REVIEW | doi:10.20944/preprints202209.0132.v1
Subject: Medicine And Pharmacology, Obstetrics And Gynaecology Keywords: tissue engineering; ovary; uterus; vagina; gynecology
Online: 9 September 2022 (07:33:27 CEST)
Female gynecological organ dysfunction can cause infertility and psychological distress, decreasing quality of life of affected women. Incidence is constantly increasing due to growing rates of cancer and delaying of childbearing age in the developed world. Current treatments are often unable to restore organ function, and occasionally are the cause for female infertility. Alternative treatment options are currently being developed in order to face the inadequacy of current practices. In this review, pathologies and current treatments of gynecological organs (ovaries, uterus, and vagina) will be described. The state-of-the-art of tissue engineering alternatives to common practices are evaluated with a focus on in vivo models. Tissue engineering is an ever-expanding field, integrating various domains of modern science to create sophisticated tissue substitutes in the hopes of repairing or replacing dysfunctional organs using autologous cells. Application to gynecology has the potential of restoring female fertility and sexual wellbeing.
REVIEW | doi:10.20944/preprints202203.0305.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: chitosan; cardiac tissue engineering; scaffolds
Online: 23 March 2022 (03:12:40 CET)
Cardiovascular diseases are the leading cause of death worldwide. Cardiovascular diseases complication can give rise to myocardial infarction which produces cell death by blockage of blood flow, leading to loss of heart function. Current treatments directed at heart repair have several disadvantages such as the lack of donors for heart transplantation or the use of non-bioactive inert materials for replacement of the damage tissue. New treatment strategies involve stimulation of heart tissue regeneration with the use of bioactive materials like chitosan, in combination with cells and biochemical factors. Chitosan scaffolds have the necessary proprieties of biocompatibility, porosity, and biodegradation, that imitates the heart extracellular matrix. Chitosan scaffolds physical proprieties, such as electrical conductivity and mechanical proprieties, can be improved by different preparation techniques and by the functionalization with other materials.
REVIEW | doi:10.20944/preprints201608.0036.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: hydrogels; tissue engineering; bioconjugation
Online: 4 August 2016 (11:00:19 CEST)
Disease, trauma, and aging account for a significant number of clinical disorders. Regenerative medicine is emerging as a very promising therapeutic option. The design and development of new cell-customized biomaterials able to mimic ECM functionalities represent one of the major strategy to control the cell fate and stimulate tissue regeneration. Recently, hydrogels have received a considerable interest for their use in the modulation and control of cell fate during regeneration processes. Several synthetic bioresponsive hydrogels are being developed in order to facilitate cell-matrix and cell-cell interactions. In this review new strategies and future perspectives of such synthetic cell microenvironment will be highlighted.
REVIEW | doi:10.20944/preprints202011.0697.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tissue engineering,; biocompatible materials; skeletal muscle
Online: 27 November 2020 (15:02:14 CET)
Tissue engineering, also called “regenerative medicine”, refers to attempt to create functional human tissue from cells in laboratory. This is a field that uses living cells, biocompatible materials, suitable biochemical and physical factors and their combinations, to create tissue-like structures.. To date, no tissue engineered skeletal muscle implants have been developed for clinical use, but it may represent a valid alternative to treat volumetric muscle loss in the near future. Herein, we reviewed the literature and showed different techniques to produce synthetic tissues with the same architectural, structural and functional properties of native tissues.
REVIEW | doi:10.20944/preprints202212.0115.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: bioactive glass; gelatin; tissue engineering; bone; composite
Online: 7 December 2022 (04:30:39 CET)
Nano/micron-sized bioactive glass (BG) particles are attractive candidates for both soft and hard tissue engineering. They can chemically bond to the host tissues, enhance new tissue formation, activate cell proliferation, stimulate the genetic expression of proteins, and trigger unique an-ti-bacterial, anti-inflammatory, and anti-cancer functionalities. Recently, composites based on bi-opolymers and BG particles have been developed with various state-of-the-art techniques for tis-sue engineering. Gelatin, a semi-synthetic biopolymer, has attracted the attention of researchers because it is derived from the most abundant protein in the body, viz., collagen. It is a polymer that can be dissolved in water and processed to acquire different configurations, such as hydro-gels, fibers, films, scaffolds, etc. Searching "bioactive glass gelatin" in the tile on Scopus renders 80 highly relevant articles published in the last ~10 years, which signifies the importance of such composites. First, this review addresses the basic concepts of soft and hard tissue engineering, in-cluding the healing mechanisms and limitations ahead. Then, current knowledge on gelatin/BG composites including composition, processing and properties is summarized and discussed both for soft and hard tissue applications. This review explores physical, chemical and mechanical features and ion-release effects of such composites concerning osteogenic and angiogenic respons-es in vivo and in vitro. Additionally, recent developments of BG/gelatin composites using 3D/4D printing for tissue engineering are presented. Finally, the perspectives and current challenges in developing desirable composites for the regeneration of different tissues are outlined.
REVIEW | doi:10.20944/preprints202111.0389.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: 3D Bioprinting; Extracellular Matrix; Extrusion; Biomaterials; Tissue Engineering
Online: 22 November 2021 (12:26:49 CET)
There is need to address the challenges of organ shortage, through development of tissues and organs with alternatives to those of the allograft-kind. This illustrates the quest behind novel biofabrication strategies such as 3D bio-printing, which is necessary to create artificial multi-cellular tissues/organs. Several findings have been reported in this review. First, the role of ECM components in tissue regenerative medicine is presented. Different ECM components such as collagen, gelatin, elastin, fibronectin, laminins and glycosaminoglycans are concisely examined for their tissue regenerative medicine applications. Next, current state of research on extrusion-based 3D bio-printing techniques and their limitations are reviewed. For example, we show that cell viability is still a challenge with extrusion, while the use of natural polymers such as collagen in improving composites’ mechanical properties is limited. Lastly, we examine unresolved research questions necessary to advance the present state of research in the field.
BRIEF REPORT | doi:10.20944/preprints202311.0315.v1
Subject: Engineering, Bioengineering Keywords: Regenerative medicine, Adhesion barriers, Tissue engineering
Online: 6 November 2023 (07:56:04 CET)
Regenerative Medicine and Tissue Engineering are interdisciplinary fields that combine cell biology, material science, and bioengineering to develop therapies for tissue repair and regeneration. This field has made significant advances in recent years, particularly in the use of stem cells and biomaterials. Advancements in cell-based therapies have involved the use of cells to repair or replace damaged tissues and organs. Tissue engineering involves using scaffolds and growth factors to promote tissue regeneration. However, a major challenge in this field is the formation of adhesions, which can cause complications, such as intestinal obstruction and chronic pain. Adhesion barriers are used to prevent adhesion of tissues and organs during recovery, thereby reducing the risk of complications. Anti-adhesion materials, such as polysaccharides, proteins, and synthetic polymers, are used to create a physical barrier between tissues and prevent adhesion. These materials can be used alone or in combination, but their effectiveness varies.
REVIEW | doi:10.20944/preprints202305.0712.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: scaffold; cell therapy; tissue-engineered vascular graft; clinical translation of tissue-engineered vascular grafts
Online: 10 May 2023 (08:35:23 CEST)
Cardiovascular diseases remain the leading cause of mortality worldwide. Although new therapies are actively being developed and used for cardiovascular pathologies, these attempts have not significantly decreased mortality rates. Regenerative medicine has made enormous progress and set promising approaches over the past half-century. However, since autologous (donor-derived) vascular grafts are lacking, an alternative prosthesis must be constructed for cardiovascular disease patients. In vascular tissue manufacturing and regenerative medicine, scientists seek to improve this significant clinical challenge using bio-fabrication techniques combining additive manufacturing, biomaterials science, and advanced cellular biology. In the last few decades, many improvements and changes in various approaches have helped develop bioengineered concepts that reflect native blood vessels’ structure and function. However, numerous challenges must be overcome to clinically translate the next generation of tissue-engineered vascular transplants. This review provides update on the cell sources, scaffold essential for cardiovascular tissue engineering, and tissue engineering approaches as prospective options for curative therapy for blood vessel disease.
ARTICLE | doi:10.20944/preprints202308.0367.v1
Subject: Engineering, Bioengineering Keywords: cartilage; autologous chondrocyte implantation; tissue engineering; hydrogels
Online: 4 August 2023 (08:36:15 CEST)
Focal cartilage defects are a prevalent knee problem affecting people of all ages. Due to its avascular nature, cartilage has limited self-repair capacity, and osteochondral defects can lead to pain and long-term complications such as osteoarthritis. Autologous chondrocyte implantation (ACI) has been a successful surgical approach for repairing osteochondral defects over the past two decades. However, a major drawback of ACI is the de-differentiation of chondrocytes during their in vitro expansion. In this study, we isolated ovine chondrocytes and cultured them in a two-dimensional environment as for ACI procedures. We hypothesised that the 3D scaffolds would support the cells re-differentiation without the need for growth factors and so we encapsulated them into soft collagen and alginate (col/alg) hydrogels. Chondrocytes embedded into hydrogels were viable and proliferated. After 7 days they acquired a rounded morphology and started to aggregate. Gene expression studies showed that the genes associated with chondrogenesis started to be up regulated as early as day one. At 21 days chondrocytes had extensively colonized the hydrogel, forming large cell clusters and started to deposit collagen II and aggrecan with limited collagen type I deposition. These findings highlight the potential of soft col/alg hydrogels to enhance ACI outcomes by creating a favourable microenvironment for chondrocyte reprogramming and re-differentiation, eliminating the dependency on growth factors.
REVIEW | doi:10.20944/preprints202211.0261.v1
Subject: Engineering, Bioengineering Keywords: Tissue Engineering; Gastrointestinal tract; urinary tract; female genital tract; hollow structure.
Online: 15 November 2022 (01:02:10 CET)
The gastrointestinal and genitourinary tracts share several similarities. Primarily, these tissues are composed of hollow structures lined by an epithelium through which materials need to flow with the help of peristalsis brought by muscle contraction. In the case of the gastrointestinal tract, solid or liquid food must circulate to be digested and absorbed and the waste products eliminated. In the case of the urinary tract, the urine produced by the kidneys must flow to the bladder, where it is stored until its elimination from the body. Finally, in the case of the vagina, it must allow the evacuation of blood during menstruation, accommodate the male sexual organ during coitus, and is the natural way to birth a child. The present review describes the anatomy, pathologies and treatments of such organs, emphasizing tissue engineering strategies.
ARTICLE | doi:10.20944/preprints202205.0396.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: scaffold; collagen vitrigel; tissue engineering; cornea; corneal endothelium
Online: 30 May 2022 (11:25:19 CEST)
We set a feasible method to produce tailored collagen scaffolds and analyzed its potential for corneal engineering. Collagen-vitrigel membranes (CVM) were produced with a 1:1 ratio of Dulbecco’s Modified Eagle’s medium (DMEM), 1% antibiotics and 8% fetal bovine serum, and 5mg/mL collagen type I. Three volumes of collagen were used: 1X (2.8 L/mm2 of collagen), 2X, and 3X. Vitrification was done at 40% relative humidity (RH), 40° C, and 30 rpm using a matryoshka system set with a shaking-oven and a desiccator with a saturated K2CO3 solution. The CVM was characterized for width, microstructure, transparency, and biocompatibility using NIH3T3 cells. Surgical manipulation was assessed in an ex vivo corneal model. Constructs of corneal endothelial cells (CECs) and 2X-CVM were transplanted into five 18-month-old White New Zealand rabbits. CVM exhibited homogeneous surface and laminar organization. Membrane width increased with gel volume from 3.65µm to 7.2µm. 1X and 2X-CVM exhibited a 99% transmittance. NIH3T3 cells concentration increased 3-fold within 48 h with no significant difference among the 3 CVM (p = 0.323). The 2X-CVM was surgically manipulable. Transplantation of corneal endothelial cells (CECs) seeded over 2X-CVM restored corneal endothelium. The matrioshka system is a feasible method that yields CVM suitable for corneal engineering.
REVIEW | doi:10.20944/preprints201808.0280.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: conductive hydrogel; tissue engineering; biomaterials; physical and electrical properties
Online: 15 August 2018 (16:12:51 CEST)
In the field of tissue engineering, conductive hydrogels have been the most effective biomaterials to mimic the biological and electrical properties of tissues in the human body. The main advantages of conductive hydrogel include not only its physical properties, but also its adequate electrical properties, thus providing electrical signals to cells efficiently. However, when introducing a conductive material into a non-conductive hydrogel, a conflicting relationship between the electrical and mechanical properties may develop. This review examines the strengths and weaknesses of the generation of conductive hydrogels using various conductive materials and introduces the use of these conductive hydrogels in tissue engineering applications.
REVIEW | doi:10.20944/preprints202311.1884.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bioceramics; 3Dprinting; Bone tissue engineering; Scaffold fabrication
Online: 29 November 2023 (10:51:22 CET)
3D Printing (3DP) technology has revolutionized the field of the use of bioceramics for maxillofacial and periodontal applications, offering unprecedented control over the shape, size, and structure of bioceramic implants. In addition, bioceramics have become attractive materials for these applications due to their biocompatibility, biostability, and favorable mechanical properties. However, despite their advantages, bioceramic implants are still associated with inferior biological performance issues after implantation, such as slow osseointegration, inadequate tissue response, and increased risk of implant failure. To address these challenges, researchers have been developing strategies to improve the biological performance of 3D printed bioceramic implants. The purpose of this review is to provide an overview of 3DP techniques and strategies for bioceramic materials designed for bone regeneration. The review also addresses the use and incorporation of active biomolecules in 3D printed bioceramic constructs to stimulate bone regeneration. By controlling the surface roughness, and chemical composition of the implant, the construct can be tailored to promote osseointegration and reduce the risk of adverse tissue reactions. Additionally, growth factors, such as bone morphogenic proteins (rhBMP-2) and pharmacologic agent (dipyridamole), can be incorporated to promote the growth of new bone tissue. Incorporating porosity into bioceramic constructs can improve bone tissue formation and the overall biological response of the implant. As such, by employing surface modification, combining with other materials, and incorporation of 3DP workflow can lead to better patient healing outcomes.
REVIEW | doi:10.20944/preprints202102.0184.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Retinal degenerative diseases; Age related macular degeneration; Biomaterials, Stem cells, Retinal pigment epithelium; Tissue engineering
Online: 8 February 2021 (10:46:50 CET)
The retina is a complex and fragile photosensitive part of the central nervous system which is prone to degenerative diseases leading to permanent vision loss. No proven treatment strategies exist to treat or reverse the degenerative conditions. Recent investigations demonstrate that cell transplantation therapies to replace the dysfunctional retinal pigment epithelial (RPE) cells and or the degenerating photoreceptors (PRs) are viable options to restore vision. Pluripotent stem cells, retinal progenitor cells and somatic stem cells are the main cell sources used for cell transplantation therapies. The success of retinal transplantation based on cell suspension injection is hindered by limited cell survival and lack of cellular integration. Recent advances in material science helped to develop strategies to grow cells as intact monolayers or as sheets on biomaterial scaffolds for transplantation into the eyes. Such implants are found to be more promising than the bolus injection approach. Tissue engineering techniques are specifically designed to construct biodegradable or non-degradable polymer scaffolds to grow cells as a monolayer and construct implantable grafts. The engineered cell construct along with the extracellular matrix formed, can hold the cells in place to enable easy survival, better integration and improved visual function. This article reviews the advances in the use of scaffolds for transplantation studies in animal models and its application in current clinical trials.
REVIEW | doi:10.20944/preprints202310.1126.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: hydrogel; gelatin; mechanical property; crosslinking; scaffold; tissue engineering
Online: 18 October 2023 (17:13:00 CEST)
In the last two decades, gelatin-based hydrogels have been widely used as tissue engineering scaffolds due to their excellent biocompatibility, biodegradability, easy processability, transparency, non-toxicity, and reasonable structural similarity to the natural extracellular matrix (ECM). However, intrinsic low mechanical properties of gelatin are not structurally and mechanically suitable to support cell growth and proliferation. That’s why various crosslinking strategies including physical, chemical, enzymatic and combination of them as well as networking patterns including double network, interpenetrating network and nano reinforcing mechanism have been utilized to enhance the structural stability and mechanical integrity of gelatin. In this review, the advances in modulating the mechanical properties of gelatin-based hydrogels for the design and development of structurally stable scaffolds for tissue engineering are discussed. The optimized crosslinking parameters with the adequate mechanical properties of gelatin-based hydrogels are reviewed. Gelatin-based scaffolds for a wide range of tissue engineering applications, such as bone, cartilage, cardiac, skin, and nerve tissue engineering are also outlined. Lastly, current challenges and future perspectives in this research field are presented.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: 3D printing; tissue engineering; periodontal regeneration; scaffolds; stem cells; growth factors
Online: 24 November 2020 (16:18:17 CET)
The three-dimensional printing of scaffolds is an interesting alternative to the traditional techniques of periodontal regeneration. This technique uses computer assisted design and manufacturing after CT scan. After 3D modelling, individualized scaffolds are printed by extrusion, selective laser sintering, stereolithography, or powder bed inkjet printing. These scaffolds can be made of one or several materials such as natural polymers, synthetic polymers, or bioceramics. They can be monophasic or multiphasic and tend to recreate the architectural structure of the periodontal tissue. In order to enhance the bioactivity and have a higher regeneration, the scaffolds can be embedded with stem cells and/or growth factors. This new technique could enhance a complete periodontal regeneration. This review summarizes the application of 3D printed scaffolds in periodontal regeneration. The process, the materials and designs, the key advantages and prospects of 3D bioprinting are highlighted, providing new ideas for tissue regeneration.
REVIEW | doi:10.20944/preprints201812.0170.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: bacterial nanocellulose; nanofibrillated nanocellulose; animal nanocellulose; algal nanocellulose; tissue engineering; tissue repair; wound dressing; cell delivery; drug delivery; antimicrobial properties
Online: 14 December 2018 (06:44:53 CET)
Nanocellulose is cellulose in the form of nanostructures, i.e. features not exceeding 100 nm at least in one dimension. These nanostructures include nanofibrils, e.g. in bacterial cellulose; nanofibers, e.g. in electrospun matrices; nanowhiskers and nanocrystals. These structures can be further assembled into bigger 2D and 3D nano-, micro- and macro-structures, such as nanoplatelets, membranes, films, microparticles and porous macroscopic matrices. There are four main sources of nanocellulose: bacteria (Gluonacetobacter), plants (trees, shrubs, herbs), algae (Cladophora) and animals (Tunicata). Nanocellulose has emerged for a wide range of industrial, technology and biomedical applications, e.g. for adsorption, ultrafiltration, packaging, conservation of historical artifacts, thermal insulation and fire retardation, energy extraction and storage, acoustics, sensorics, controlled drug delivery, and particularly for tissue engineering. Nanocellulose is promising for use in scaffolds for engineering of blood vessels, neural tissue, bone, cartilage, liver, adipose tissue, urethra and dura mater, for repairing connective tissue and congenital heart defects, and for constructing contact lenses and protective barriers. This review is focused on applications of nanocellulose in skin tissue engineering and wound healing as a scaffold for cell growth, for delivering cells into wounds, and as a material for advanced wound dressings coupled with drug delivery, transparency and sensorics. Potential cytotoxicity and immunogenicity of nanocellulose are also discussed.
REVIEW | doi:10.20944/preprints201609.0091.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: biomaterial; scaffold; protein; keratin; tissue engineering
Online: 26 September 2016 (10:25:01 CEST)
In tissue engineering scaffolds take the place of the natural extra cellular matrix (ECM). The natural ECM is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The design aspect along with the choice of the material for the artificial scaffold is very crucial to cell differentiation, adhesion, proliferation, and the transport of the growth factors or other bio molecular signals. In addition to the material and design of the scaffolds, it is necessary to replicate the normal physiological situation if the scaffold has to function as an implant. The cells have to be located in the porous scaffold to form a three dimensional assembly. The article discusses the important factors to be considered while designing a scaffold for tissue engineering and regenerative medicine.
REVIEW | doi:10.20944/preprints202311.1021.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: cryogels; scaffolds; tissue engineering; bone reconstruction; cartilage reconstruction
Online: 16 November 2023 (02:51:42 CET)
Critical sized bone defects and articular cartilage injuries resulting from trauma, osteonecrosis or age-related degeneration are often nonhealing by the physiological repairing mechanisms, thus representing a clinic issue due to the relevant epidemiological incidence. Current treatment approaches consist of autologous or allogenic grafting, which are associated with painfulness, morbidity, risk of infections and rejection. Novel tissue-engineering approaches, aiming at the reconstruction of damaged tissues, have been proposed as alternative solutions to these conven-tional methods. These approaches are based on the combination of three fundamental compo-nents: autologous or allogenic cells, a scaffold and growth-stimulating signals, which are gener-ally referred to as the tissue engineering triad. Three-dimensional polymer networks are fre-quently used as scaffolds to allow cell proliferation and tissue regeneration. In this scenario, cryogels are giving promising results as cell scaffolds over other polymer networks, thanks to their peculiar properties. In particular, cryogels possess an interconnected porous structure and a typical sponge-like behaviour, which facilitate the cellular infiltration and ingrowth. Their properties can be appropriately adjusted to match the requirements of the specific tissue or or-gan that it is intended to regenerate. In this review it is reported the state of the art on the fabri-cation and employment of cryogels in supporting osteo or chondro-genic differentiation for the re-building of more organized tissues. Moreover, it will highlight current progress and future perspectives in the implementation of this technology in the clinical practice.
ARTICLE | doi:10.20944/preprints201703.0011.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: Poly (lactic acid); chitosan; calcium silicate; tissue engineering; osteogenesis
Online: 1 March 2017 (17:03:43 CET)
Electrospinning is the versatile technique to generate large quantities of micro- or nano-fibers from a wide variety of shapes and sizes of polymer. Natural bone is a hierarchically composites with the dispersion of inorganic ceramic along organic polymer. The aim of this study, the electrospun poly (lactic acid) (PLA) mats coated with chitosan (CH) and calcium silicate (CS) powder were fabricated. The morphology, chemical composition, and surface properties of CS/CH-PLA composites were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. In vitro, the CS/CH-coated PLA mats increased the formation of apatite on the surface when soaking in cell cultured medium. During culture, the adhesion and proliferation of the human mesenchymal stem cells (hMSCs) cultured on CS/CH-PLA were significantly promoted relative to those on PLA. Collagen I and fibronectin levels and promoted cell adhesion were observed upon an increase in CS content. Further, compared to PLA mats without CS/CH, CS10 and CS15 mats markedly enhanced the proliferation of hMSCs as well as their osteogenesis properties, which was characterized by bone-related gene expression. Our results demonstrated that the biodegradable and electroactive CS/CH-PLA mats had potential application as an ideal candidate for bone tissue engineering. Together, findings from this study clearly demonstrated that PLLA-C2S composite scaffold may function as an ideal candidate for bone tissue engineering.
ARTICLE | doi:10.20944/preprints201807.0021.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: biomaterials; cobalt ferrites; poly(hydroxybutyrate-co-hydroxyvalerate); tissue engineering
Online: 3 July 2018 (05:12:53 CEST)
Polymer-based piezoelectric biomaterials have already proven their relevance for tissue engineering applications. Further, the morphology of the scaffolds plays also an important role in cell proliferation and differentiation. The present work reports on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), a biocompatible, biodegradable and piezoelectric biopolymer that has been processed in different morphologies, including films, fibres, microspheres and 3D scaffolds. Further, the corresponding magnetically active PHBV-based composites were also produced. The effect of the morphology on physico-chemical, thermal, magnetic and mechanical properties of pristine and composites samples was evaluated, as well as their cytotoxicity. It was observed that the morphology does not strongly affect the properties of the pristine samples but the introduction of cobalt ferrites induces changes in the degree of crystallinity that could affect the applicability of prepared biomaterials. Young modulus is dependent of the morphology and also increases with the addition of cobalt ferrites. Both, pristine and PHBV/cobalt ferrite composite samples are no cytotoxic, indicating their suitability for tissue engineering applications.
REVIEW | doi:10.20944/preprints202102.0418.v1
Subject: Engineering, Automotive Engineering Keywords: Integrins; RGD; contractility; collagen tissue; engineering; adhesion molecules; myocardial infarct
Online: 18 February 2021 (12:23:02 CET)
Currently, the clinical impact of cell therapy after a myocardial infarction (MI) is limited by low cell engraftment due to significant cell death, including apoptosis, in an infarcted, inflammatory, poor angiogenic environment, low cell retention and secondary migration. Cells interact with their environment through integrin mechanoreceptors that control their survival/apoptosis/differentiation/migration/proliferation. Optimizing these interactions may be a way of improving outcomes. The association of free cells with a 3D-scaffold may be a way to target their integrins. Collagen is the most abundant structural component of the extracellular matrix (ECM) and the best contractility levels are achieved with cellular preparations containing collagen, fibrin, or Matrigel (i.e. tumor extract). In the interactions between cells and ECM, 3 main proteins are recognised: collagen, laminin and RGD (Arg-Gly-Asp) peptide. The RGD plays a key role in heart development, after MI, and on cardiac cells. Cardiomyocytes secrete their own laminin on collagen. The collagen has a non-functional cryptic RGD and is thus suboptimal for interactions with associated cells. The use of a collagen functionalized with RGD may help to improve collagen biofunctionality. It may help in the delivery of paracrine cells, whether or not they are contractile, and in assisting tissue engineering a safe contractile tissue.
REVIEW | doi:10.20944/preprints201807.0241.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: biomaterial; bone regeneration; drug release; hydrogel; lignin; multivariate data processing; osteogenesis; scaffolds; stem cells; tissue engineering
Online: 13 July 2018 (15:07:37 CEST)
Renewable resources gain increasing interest as source for environmentally benign biomaterials, such as drug encapsulation/release compounds, and scaffolds for tissue engineering in regenerative medicine. Being the second largest naturally abundant polymer, the interest in lignin valorization for biomedical utilization is rapidly growing. Depending on resource and isolation procedure, lignin shows specific antioxidant and antimicrobial activity. Today, efforts in research and industry are directed toward lignin utilization as renewable macromolecular building block for the preparation of polymeric drug encapsulation and scaffold materials. Within the last five years, remarkable progress has been made in isolation, functionalization and modification of lignin and lignin-derived compounds. However, literature so far mainly focuses lignin-derived fuels, lubricants and resins. The purpose of this review is to summarize the current state of the art and to highlight the most important results in the field of lignin-based materials for potential use in biomedicine (reported in 2014–2018). Special focus is drawn on lignin-derived nanomaterials for drug encapsulation and release as well as lignin hybrid materials used as scaffolds for guided bone regeneration in stem cell-based therapies.
ARTICLE | doi:10.20944/preprints202101.0594.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Hybrid scaffold; Bioactive Glass; Gelatin; GPTMS; Bone tissue engineering
Online: 28 January 2021 (16:13:18 CET)
Hybrid scaffolds based on bioactive glass (BAG) particles (<38µm), covalently linked to the gelatin (G*), using 3-glycidoxypropyltrimethoxysilane (GPTMS), have been studied for bone bioengineering. In this study, two glass compositions (13-93 and 13-93B20 [where 20% of the SiO2 was replaced with B2O3]) were introduced in the gelatin matrix. The Cfactor (Gelatin/GPTMS molar ratio) was kept constant at 500. The hybrids obtained were found to be stable at 37°C, in solution; condition at which pure gelatin is liquid. All hybrids were characterized by in vitro dissolution in TRIS solution (for up to 4 weeks) and Simulated Body Fluid (SBF) (for up to 2 weeks). Samples processed with 13-93B20 exhibit a faster initial dissolution and significantly faster precipitation of a hydroxyapatite (HA) layer. The faster ion release and HA precipitation recorded from the G*/13-93B20 samples, is attributable to the higher reactivity of borosilicate compared to the silicate glass. MC3T3-E1 cells behavior, in direct contact with the hybrids, was investigated, showing that the cells were able to proliferate and spread on the developed biomaterials. Tailoring the glass composition allows to better control the material’s dissolution, biodegradability, and bioactivity. Bioactive (especially with 13-93B20 BAG), and biocompatible, the hybrids are promising for bone application.
ARTICLE | doi:10.20944/preprints201610.0118.v1
Subject: Physical Sciences, Optics And Photonics Keywords: tissue-like phantoms; dual-modal imaging; fluorescence lifetime (FLT); FLT imaging (FLIM); diffusion reflection
Online: 27 October 2016 (11:52:21 CEST)
Tissue-like phantoms are widely used as a model for mimicking the optical properties of live tissue. This paper presents the results of a diffusion reflection method as well as fluorescence lifetime imaging microscopy measurements of fluorescein-conjugated gold nanorods in solution as well as inserted in solid tissue-imitating phantoms. A lack of consistency between the fluorescence lifetime results of the solutions and the phantoms raises a question about the ability of tissue-like phantoms to maintain the optical properties of inserted contrast agents.
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bioactive glasses; Alkali-free; Sol-gel; Bone regeneration; Tissue engineering.
Online: 1 July 2021 (11:20:51 CEST)
In bone tissue engineering, ceramics have been the choice due to their excellent biological properties. But the paradigm changed with the discovery of bioactive glasses (BGs) in 1969 by Larry Hench and co-workers, due to their ability to bond to living tissues through the formation of an interfacial bone-like hydroxyapatite layer when the bioglass was put in contact with biological fluids in vivo. Among a number of tested compositions, the one exhibiting the highest bioactivity index is the well-known trademarked 45S5 Bioglass®. The topic received increasing attention particularly after 1985 when this material entered in the market of biomedical devices, inspiring many other investigations aiming at further exploring the in vitro and in vivo performances of this BG, or developing other related BG compositions. The research efforts gradually revealed a number of shortcomings of 45S5 Bioglass®, mostly derived from its high sodium content, initially intended to decrease the melting temperature and accelerating the degradation of the silicate network over time. But the extensive release of sodium from 45S5 Bioglass® in the biological fluids creates a high pH cytotoxic environment. Other serious drawbacks include a fast degradation rate, and a poor sintering ability, which hinders the reliable fabrication of porous scaffolds. Therefore, sol-gel was regarded as an attractive alternative to prepare alkali-free BG compositions. The process uses inorganic and/or organic precursors, which undergo hydrolysis and condensation at room-temperature, being less costly. When properly conducted, the sol-gel process might result in amorphous structures with all the components intimately mixed at the atomic scale. Moreover, developing new better performing materials for bone tissue engineering is a growing concern, as the ageing of the world’s population leads to lower bone density and osteoporosis. This work describes the sol-gel synthesis of a novel quaternary silicate-based BG with the composition 60 SiO2 – 34 CaO – 4 MgO – 2 P2O5 (mol%) was prepared using acidified distilled water as single solvent. By controlling the kinetics of the hydrolysis and condensation steps, an amorphous glass structure could be obtained. The results of XRD of samples calcined within the temperature range from 600-900 ºC demonstrated that amorphous nature was maintained until 800 ºC, followed by partial crystallization at 900 ºC. The specific surface area, an important factor in osteoconduction, was also evaluated over different temperatures, ranging from 160.6 ± 0.8 m2/g at 600 ºC down to 2.2 ± 0.1 m2/g at 900 ºC, being accompanied consistent changes in average pore size and agreeing pore size distribution. The immersion of the BG particles in simulated body fluid (SBF) led to the formation of an extensive apatite layer on its surface. These overall results indicate the proposed material is very promising for biomedical applications in bone regeneration and tissue engineering.
REVIEW | doi:10.20944/preprints202310.1082.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: multi-scale; hierarchical structure; porous scaffold; bone tissue engineering; bone regeneration
Online: 18 October 2023 (02:34:08 CEST)
In recent decades, porous scaffolds for bone tissue engineering (BTE) have gained significant attention. Considerable research efforts have been dedicated to investigating the impact of scaffold pore size on a diverse array of biological processes, including cell-scaffold interactions, substance transportation, and vascularization. However, the multi-scale hierarchical porosity, a key structural characteristic of natural bone, has rarely been replicated in BTE scaffolds due to the challenges of controlling the scaffold structure across multiple length scales. With the advancement of manufacturing technology, there has been increasing research on biomimetic multi-scale hierarchical materials, which are also gaining favor in the field of BTE. Therefore, there is an urgent need to review multi-scale hierarchical porous BTE scaffolds. This paper aims to review the role and fabrication methods of multi-scale porous BTE scaffolds at different length scales, the design and manufacturing of new BTE scaffolds for bone regeneration.
REVIEW | doi:10.20944/preprints202104.0348.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: porous tantalum; clinical application; additive manufacturing; surface modification; bone tissue engineering
Online: 13 April 2021 (11:36:57 CEST)
Porous tantalum (Ta) is a promising biomaterial and has been applied in orthopedics and dentistry for nearly two decades. The high porosity and interconnected pore structure of porous Ta promise fine bone ingrowth and new bone formation within the inner space, which further guarantee rapid osteointegration and bone-implant stability in long term. Porous Ta has high wettability and surface energy that can facilitate adherence, proliferation and mineralization of osteoblasts. Meanwhile, low elastic modulus and high friction coefficient of porous Ta can effectively avoid stress shield effect, minimize marginal bone loss and ensure primary stability. Accordingly, the satisfactory clinical application of porous Ta based implants or prostheses are mainly derived from its excellent biological and mechanical properties. With the advent of additive manufacturing, personalized porous Ta based implants or prostheses have shown their clinical value in the treatment of individual patient who need specially designed implant or prosthesis. In addition, many modification methods have been introduced to enhance the bioactivity and antibacterial property of porous Ta with promising in vitro and in vivo research results. In any case, choosing suitable patients is of great importance to guarantee surgical success after porous Ta insertion.
ARTICLE | doi:10.20944/preprints201807.0387.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: membrane fouling; membrane plasticization; nutrients transport properties; perfusion bioreactors; tissue engineering
Online: 20 July 2018 (14:01:37 CEST)
High porosity and mass transport properties of microfiltration polymeric membranes benefits nutrients supply to cells when used as scaffolds in interstitial perfusion bioreactors for tissue engineering. High nutrients transport is assumed when pore size and porosity of the membrane are in the micrometric range. The present work demonstrates that the study of membrane fouling by proteins present in the culture medium, though not done usually, should be included in the routine testing of new polymer membranes for this intended application. Two poly(ε-caprolactone) microfiltration membranes presenting similar average pore size (~0.7µm) and porosity (>80%) but different external surface porosity and pore size have been selected as case study. The present work demonstrates that a membrane with lower surface pore abundance and smaller external pore size (~0.67 µm), combined with adequate hydrodynamics and tangential flow filtration mode is usually more convenient to guarantee high flux of nutrients. On the contrary, having large external pore size (~1.70µm) and surface porosity would incur in important internal protein fouling that could not been prevented with the operation mode and hydrodynamics of the perfusion system. Additionally, the use of glycerol in the drying protocols of the membranes might cause plasticization and a consequent reduction of mass transport properties due to membrane compaction by the pressure exerted to force perfusion. Therefore, preferentially, drying protocols that omit the use of plasticizing agents are recommended.
ARTICLE | doi:10.20944/preprints201611.0150.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: water-based polyurethane; hyaluronic acid; cartilage tissue engineering; scaffold
Online: 30 November 2016 (04:28:15 CET)
Diseases in articular cartilages have affected millions of people globally. Although the biochemical and cellular composition of articular cartilages is relatively simple, there is the limitation in self-repair ability of cartilage. Therefore, developing the strategies for cartilage repair is very important. Here, we reported a new manufacturing process of water-based polyurethane based photosensitive materials with hyaluronic acid and applied the materials for 3D printed customized cartilage scaffolds. The scaffold has high cytocompatibility and is one that closely mimics the mechanical properties of articular cartilages. It is suitable for culturing human Wharton's jelly mesenchymal stem cells (hWJMSCs) and the cells showed an excellent chondrogenic differentiation capacity. We consider that the 3D printing hybrid scaffolds may have potential in customized tissue engineering and facilitate the development of cartilage tissue engineering.
ARTICLE | doi:10.20944/preprints202308.1671.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: hydrogel; gelatin; chitosan; conductive carbon black; nanocomposite; cyclic compression; dissipation energy; anisotropy; tissue engineering
Online: 23 August 2023 (11:53:29 CEST)
Conductive nanocomposites play a significant role in tissue engineering by providing a platform to support cell growth, tissue regeneration, and electrical stimulation. In this present study, a set of electroconductive nanocomposite hydrogels based on gelatin (G), chitosan (CH) and conductive carbon black (CB) was synthesized with the aim to develop novel biomaterials for tissue regeneration application. Incorporation of conductive carbon black (10, 15 and 20 wt %) significantly improved electrical conductivity and enhanced mechanical properties with the increased CB content. We employed an oversimplified unidirectional freezing technique to impart anisotropic morphology with interconnected porous architecture. An investigation into whether any anisotropic morphology affects the mechanical properties of hydrogel was conducted by performing compression and cyclic compression tests in each direction parallel and perpendicular to macroporous channels. Interestingly, nanocomposite with 10 % CB produced both anisotropic morphology and mechanical property, whereas anisotropic pore morphology diminished at higher CB concentration (15 and 20 %) imparting denser texture. Collectively, the nanocomposite hydrogels showed great structural stability as well as good mechanical stability and reversibility. Under repeated compressive cyclic at 50 % deformation, the nanocomposite hydrogels showed preconditioning, characteristic hysteresis, nonlinear elasticity, and toughness. Overall, the collective mechanical behavior resembled the mechanics of soft tissues. Electrical impedance associated to the hydrogels was studied in terms of modulus and phase in dry and wet condition. The electrical properties conducted in wet conditions, which is more physiologically relevant, showed low impedance at high frequencies due to capacitive currents. Overall, impedance of the nanocomposite hydrogels decreased with increased CB concentrations. These gelatin-chitosan–carbon black nanocomposite hydrogels show great promise for use as conducting substrates for the growth of electro-responsive cells in tissue engineering.
ARTICLE | doi:10.20944/preprints202305.1473.v1
Subject: Engineering, Bioengineering Keywords: Decellularization; heart valve; tissue engineering; xenograft; biomaterial
Online: 22 May 2023 (08:26:48 CEST)
In order to overcome the disadvantages of existing treatments in heart valve tissue engineering, decellularization studies are carried out. The main purpose of decellularization is to eliminate the immunogenicity of biologically derived grafts and to obtain a scaffold that allows recellularization while preserving the natural tissue architecture. SD and SDS are detergent derivatives frequently used in decellularization studies. The aim of our study is to decellularize the pulmonary heart valves of young Merino sheep by using low-density SDS and SD detergents together, and then to perform their detailed characterization to determine whether they are suitable for clinical studies. Pulmonary heart valves of 4-6 month old sheep were decellularized in detergent solution for 24 hours. The amount of residual DNA was measured to determine the efficiency of decellularization. Then, the effect of decellularization on the ECM by histological staining was examined. In addition, the samples were visualized by SEM to determine the surface morphologies of the scaffolds. Uniaxial tensile test was performed to examine the effect of decellularization on biomechanical properties. The results showed DNA removal of 94% and 98% from the decellularized leaflet and artery portions after decellularization relative to the control group. No cell nuclei were found in histological staining and it was observed that the 3-layer leaflet structure was preserved. As a result of the tensile test, it was determined that there was no statistically significant difference between the control and decellularized groups in the UTS and elasticity modulus, and the biomechanical properties did not change. In conclusion, we suggest that the pulmonary valves of decellularized young Merino sheep can be used as a initial matrix in heart valve tissue engineering studies.
REVIEW | doi:10.20944/preprints202202.0176.v1
Subject: Engineering, Bioengineering Keywords: Polymeric Biomaterials; Natural Cellulose; Tissue Engineering; Differentiation; Bone Regeneration; Skin Regeneration; Cardiac Regeneration; Vascular Regeneration; Neural Regeneration
Online: 14 February 2022 (14:02:16 CET)
In the recent years, tissue engineering researchers have exploited a variety of biomaterials that can potentially mimic extracellular matrix (ECM) for tissue regeneration. Natural cellulose, mainly obtained from bacterial (BC) and plant-based (PC) sources, can serve as a high potential scaffold material for different regenerative purposes. Natural cellulose has drawn the attention of researchers due to its advantage over synthetic cellulose in terms of availability, cost-effectiveness, perfusablility, biocompatibility, negligible toxicity, mild immune response and due to imitating native tissues. In this article, we will review the recent in vivo and in vitro studies aimed to assess the potentials of natural cellulose for the purpose of soft (skin, heart, veins, nerve, among others) and hard (bone and tooth) tissue engineering.
ARTICLE | doi:10.20944/preprints202104.0047.v2
Subject: Chemistry And Materials Science, Biomaterials Keywords: Hydrogels; Sodium alginate; Betamethasone; Drug delivery; Cartilage tissue engineering
Online: 6 April 2021 (10:03:04 CEST)
Hydrogels obtained from the combination of different polymers are an interesting strategy for the development of controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using different concentration of the components. The hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and swelling degree; betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay shown that almost all hydrogels are cytocompatibles and an increase the proliferation in both cell types after one week of incubation was observed by Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics and biocompatibility.
ARTICLE | doi:10.20944/preprints202310.1438.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: peripheral nerve tissue engineering; electrical stimulation; hydrogels; PC12 cells
Online: 23 October 2023 (11:14:08 CEST)
Extensive damage to peripheral nerves is a health problem with few therapeutic alternatives. In this context, the development of tissue engineering seeks to obtain materials that can help recreate environments conducive to cellular development and functional repair of peripheral nerves. Different hydrogels have been studied and presented as alternatives for future treatments to emulate the morphological characteristics of nerves. Along with this, other research proposes the need to incorporate electrical stimuli into treatments as agents that promote cell growth and differentiation; however, no precedent correlates the simultaneous effects of the types of hydrogel and electrical stimuli. In this research, the neural differentiation of PC12 cells we are evaluated, relating the effect of collagen, alginate, GelMA, and PEGDA hydrogels with electrical stimulation modulated in four different ways. Our results show significant correlations for different culture conditions, allowing us to develop new experimental schemes for new materials in peripheral nerve engineering.
COMMUNICATION | doi:10.20944/preprints202306.0887.v1
Subject: Engineering, Bioengineering Keywords: 3D Bioprinting; neuro-cardiac junctions; 3D tissue model; Cardiomyocytes; Neuroblastoma cells
Online: 13 June 2023 (08:33:59 CEST)
In this study, we designed a functional neuro-cardiac model to help us examine the role of neuronal regulation and confirm the importance of neural innervation techniques for cardiac tissue regeneration. A three-dimensional (3D) bioprinted neuro-cardiac scaffold composed of a mixture of gelatin-alginate and alginate-genipin-fibrin hydrogels was developed with a 2:1 ratio of AC16 cardiomyocytes (CMs) and retinoic acid differentiated SH-SY5Y neuronal cells (NCs) respectively. A unique semi-3D bioprinting approach was adopted where the CMs were mixed in the cardiac bioink and printed using an anisotropic accordion design to mimic the physiological tissue architecture in vivo. The voids in this 3D structure were methodically filled in using a NCs-gel mixture and cross-linked. Confocal fluorescent imaging using Microtubule-associated protein 2 (MAP-2) antibodies for labeling NCs, and the MyoD1 antibody for CMs revealed functional coupling between the two cell types in the final cross-linked structure. This data confirmed the development of a physiologically functional neuro-cardiac model that can be used to study neuro-cardiac modulation under physiological and pathological conditions.
ARTICLE | doi:10.20944/preprints201701.0137.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: cell culture; bioreactor; live cell imaging; tissue engineering
Online: 31 January 2017 (12:39:46 CET)
Here, we present a staged approach for an innovative repurposing of a portable infant humidicrib into a live cell growth, observation, and imaging system. Furthmore, humidicrib can support different variations of “umbilical” bioreactors, and can be used to conduct electrophysiology experiments and in situ immunohistochemistry. Modifications incorporate a closed loop carbon dioxide (CO2) concentration control system with umbilical CO2 and heating support for tailored bioreactors. The repurposing cost is inexpensive and allows for the continued observation and imaging of cells. This prototype unit has been used to continuously observe and image live primary neurons for up to 21 days. This demonstrates the repurposed units’ suitability for use in tissue culture based research, particularly where modifications to microscopes are required or where sensitive manipulation outside of a standard incubator is needed.
ARTICLE | doi:10.20944/preprints202201.0221.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Polycaprolactone; Hydroxyapatite; Composites; Solvent casting; Melt blending; 3D printing; Cytocompatibility; Bone tissue engineering
Online: 17 January 2022 (11:29:33 CET)
Bone tissue engineering has been developed in the past decades, with the engineering of bone substitutes on the vanguard of this regenerative approach. PCL based scaffolds are fairly applied for bone regeneration, and several composites have been incorporated, as to improve the devices’ mechanical properties and tissue ingrowth. In this study, HA was incorporated on PCL based scaffolds with two different proportions, 80:20 and 60:40. Devices were produced with two different techniques, SC and MB, and further investigated with regards to their mechanical characteristics and in vitro cytocompatibility. Results show the MB devices to present more promising mechanical properties, along with the incorporation of HA. The latter is also related to an increase in osteogenic activity and promotion. Overall, this study suggest PCL:HA scaffolds to be promising candidates for bone tissue engineering, particularly when produced by the MB method.
ARTICLE | doi:10.20944/preprints202109.0085.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: chick embryo; 3D culture; tumor models in vitro; tissue engineering; metastasis; triple-negative breast cancer; liver; mesoporous silica nanoparticles; doxorubicin; micrometastasis
Online: 6 September 2021 (11:46:54 CEST)
Colonization of distant organs by tumor cells is a critical step of cancer progression. The initial avascular stage of this process (micrometastasis) remains almost inaccessible to study due to the lack of relevant experimental approaches. Here, we introduce an in vitro/in vivo model of organ-specific micrometastases of triple-negative breast cancer (TNBC) that is fully implemented in a cost-efficient chick embryo (CE) experimental platform. The model is built as three-dimensional (3D) tissue engineering constructs (TECs) combining human MDA-MB-231 cells and decellular-ized CE organ-specific scaffolds. TNBC cells colonized CE organ-specific scaffolds in 2-3 weeks, forming tissue-like structures. The feasibility of this methodology for basic cancer research, drug development and nanomedicine was demonstrated on a model of hepatic micrometastasis of TNBC. We revealed that MDA-MB-231 differentially colonize parenchymal and stromal com-partments of the liver-specific extracellular matrix (LS-ECM) and become more resistant to the treatment with molecular Doxorubicin (Dox) and Dox-loaded mesoporous silica nanoparticles than in monolayer cultures. When grafted on CE chorioallantoic membrane, LS-ECM-based TECs induced angiogenic switch. These findings may have important implications for the diag-nosis and treatment of TNBC. The methodology established here is scalable and adaptable for pharmacological testing and cancer biology research of various metastatic and primary tumors.
ARTICLE | doi:10.20944/preprints201903.0087.v2
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: tissue hypoxia; sleep disordered breathing; primary snoring; molecular tissue oximeter
Online: 16 August 2019 (06:27:46 CEST)
Pulse oximetry is the current standard for detecting drops in arterial blood oxygen saturation (SpO2) associated with obstructive sleep apnea and hypopnea events in polysomnographic (PSG) testing. In cases of hypoxic challenge, such as occurs during apneic events, regulatory mechanisms restrict blood flow to the skin to preferentially maintain SpO2 for more vital organs. As a result, a measure related to skin tissue oxygenation is likely to be more sensitive to inadequate breathing during sleep than pulse oximetry. Energy Conversion Monitoring (ECM) provides a method for measuring skin tissue oxygen-dependent energy conversion and, as such, is promising for more sensitively detecting sleep disordered breathing (SDB) events compared to pulse oximetry. We hypothesized that ECM would detect hypoxia occurring with SDB events associated with drops in SpO2 but also would detect hypoxic challenge occurring with SDB events not associated with drops in SpO2 (hypopneas defined by a drop in nasal pressure occurring in conjunction with an arousal, respiratory-related arousals, and primary snoring). Primary snoring is of particular interest with respect to the potential of ECM because it is statistically associated with co-morbidities of SDB, such as hypertension, but is not considered pathological because of the lack of a proximal measure of pathology occurring with PSG. In this article we review ECM technology and methodology, present preliminary data indicating that it detects hypoxia occurring in the skin during SDB events that is not detected as blood desaturation by pulse oximetry, and make the case that it is a promising tool for identifying pathology occurring at the mild end of the SDB spectrum.
ARTICLE | doi:10.20944/preprints202302.0443.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: carcass quality; beef cattle; adipose tissue; muscle tissue; transcriptomics
Online: 27 February 2023 (04:56:02 CET)
Targets for finished livestock are often determined by expected fat, either subcutaneous or intramuscular. These targets are used frequently to improve the chances of acceptable eating quality. Lower intramuscular fat, lack of product uniformity, and reduced or insufficient tenderness can negatively impact beef acceptability. This study aimed to investigate differences in gene expression that potentially alter subsequent metabolism and intercellular signaling in the muscle and proximate intermuscular and subcutaneous adipose tissue in beef carcasses at different fat endpoints. In this study, Longissimus thoracis muscle samples and associated adipose tissue were collected at harvest. RNA was harvested from both tissues, and individual samples were sequenced using RNAseq. Differential expression was determined using edgeR, and p-values were adjusted using the Benjamini-Hochberg method. A corrected p-value of 0.005 and log₂ (fold change) of 1 was set as the threshold to identify differential expression of genes. Comparison between intermuscular fat and subcutaneous fat showed no differences between the genes activated in the two adipose tissue depots, suggesting that subcutaneous fat could be sampled to evaluate changes in adipose tissue. Carcass data allowed the classification of carcasses by projected USDA quality grades (marbling targets). In the comparison between muscle from Standard and Choice carcasses, 15 genes were downregulated, and 20 were upregulated. The insulin receptor substrate 1 (IRS 1) gene was the only known functionally important gene to be differentially expressed. There were 49 downregulated genes and 113 upregulated genes in the comparison between adipose tissue from Standard and Choice carcasses. These genes are mostly related to the metabolism of fat and energy. This potentially indicates that muscle is not changing at the transcript level as much as the adipose tissue at the sampled endpoints. Also, subcutaneous fat can be used to evaluate transcript changes in both subcutaneous and intermuscular fat. However, it is not clear if these fat tissues can be used as surrogates for intramuscular fat or marbling.
ARTICLE | doi:10.20944/preprints202111.0171.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Hyaluronic acid; hydrogels; injectable; tissue engineering; endodontic tissue regeneration
Online: 9 November 2021 (13:27:21 CET)
Dental pulp tissue engineering (TE) quests to regenerate dentin/pulp complex by combining a suitable supporting matrix, stem cells, and biochemical stimuli. Such procedures foresee a matrix that can be easily introduced into the root canal system (RCS) and tightly adhere to dentin walls to assure the dentin surface's proper colonization with progenitor cells capable of restoring the dentin/pulp complex. Herein was investigated an injectable self-setting hyaluronic acid-based (HA) hydrogel system, formed by aldehyde-modified (a-HA) with hydrazide-modified (ADH), enriched with platelet lysate (PL), for endodontic regeneration. The hydrogels' working (wT) and setting (sT) times, the adhesion to the dentine walls, the hydrogel's microstructure, and the delivery of human Dental Pulp Cells (DPCs) were studied in vitro. Hydrogels incorporating PL showed a suitable wT and sT and a porous microstructure. The tensile tests showed that the breaking point occurs after 4.13 mm deformation. While in the indentation test after 1.3 mm deformation. Both breaking points occur in the hydrogel extension. The HA/PL hydrogels exhibited supportive properties and promoted cell migration toward dentin surfaces in vitro. Overall, these results support using PL-laden HA injectable hydrogels (HA/PL) as a biomaterial for DPCs encapsulation, thereby displaying great clinical potential towards endodontic regenerative therapies.
DATA DESCRIPTOR | doi:10.20944/preprints202108.0388.v1
Subject: Engineering, Mechanical Engineering Keywords: Sclera tissue; biaxial testing; soft tissue mechanics; mechanical properties
Online: 18 August 2021 (14:25:26 CEST)
A better understanding of diseases progress in tissues vest on the accurate understanding of tissues under mechanical loading. Also, development of therapies for injuries may depend on the available mechanical data for soft tissues. In this study, the raw data of biaxial tensile testing of sclera soft tissue is presented in this paper. Biaxial mechanical testing of soft tissues presents details understanding of how soft tissues behave when compared to uniaxial testing. Biomechanical properties of soft tissues are vital in the development of accurate computational models. Reliable computational models of studying mechanisms of diseases depends mainly on the accurate and more details mechanical behavior of soft tissues. These accurate and detailed computational models may be utilized to further develop the understanding and therapies of various diseases. The mechanical tensile testing was conducted on the passive sheep sclera. Engineering stress vs strain of several samples of the sheep sclera are further presented determined from force and displacement experimental data. The goal of this paper is to make available biaxial data of sheep sclera soft tissue that can be further utilized.
ARTICLE | doi:10.20944/preprints202010.0428.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Injured tissue; Tissue remodeling; Treatment resistance; Radioisotope; Cancer stroma
Online: 21 October 2020 (10:36:25 CEST)
Background: In treatment-refractory cancers, tumor tissues damaged by therapy initiate the repair response; therefore, tumor tissues must be exposed to an additional burden before successful repair. We hypothesized that an agent recognizing a molecule that responds to anticancer treatment–induced tissue injury could deliver an additional antitumor agent including a radionuclide to damaged cancer tissues during repair. We selected the extracellular matrix glycoprotein tenascin-C (TNC) as such a molecule, and three antibodies recognizing human and murine TNC were employed to evaluate X-irradiation–induced changes in TNC uptake by subcutaneous tumors. Methods: TNC expression was assessed by immunohistochemical staining of BxPC-3 tumors treated with or without X-irradiation (30 Gy) for 7 days. Antibodies against TNC (3-6, 12-2-7, TDEAR) and a control antibody were radiolabeled with 111In and injected into nude mice having BxPC-3 tumors 7 days after X-irradiation, and temporal uptake was monitored for an additional 4 days by biodistribution and single-photon emission computed tomography with computed tomography (SPECT/CT) studies. Intratumoral distribution was analyzed by autoradiography. Results: The immunohistochemical signal for TNC expression was faint in nontreated tumors but increased and expanded with time until day 7 after X-irradiation. Biodistribution studies revealed increased tumor uptake of all three 111In-labeled antibodies and the control antibody. However, a statistically significant increase in uptake was evident only for 111In-labeled 3-6 (35%ID/g for 30 Gy vs. 15%ID/g for 0 Gy at day 1, P < 0.01; ID, injected dose), whereas limited changes in 111In-labeled TDEAR2, 12-2-27, and control antibody were observed (several %ID/g for 0 and 30 Gy). Serial SPECT/CT imaging with 111In-labeled 3-6 or control antibody provided consistent results. Autoradiography revealed noticeably stronger signals in irradiated tumors injected with 111In-labeled 3-6 compared with each of nonirradiated tumors and the control antibody. The signals were observed in TNC-expressing stroma. Conclusion: Markedly increased uptake of 111In-labeled 3-6 in irradiated tumors supports our concept that an agent, such as an antibody, that recognizes a molecule, such as TNC, involved in tissue-injury repair could enhance drug delivery to therapy-experienced tumor tissues. The combination of antibody 3-6 coupled to a tumoricidal drug and conventional therapy has the potential to achieve better outcomes for patients with refractory cancer.
ARTICLE | doi:10.20944/preprints202203.0323.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: Apolipoprotein A-1; High-density lipoprotein; Brown adipose tissue; White adipose tissue; Beige (Hybrid) adipose tissue
Online: 24 March 2022 (05:26:34 CET)
In the present study, we studied the effect of apolipoprotein A-1 (APOA1) on the spatial and molecular characteristics of bone marrow adipocytes, using well-characterized ApoA1 knockout mice. APOA1 is a central regulator of high-density lipoprotein cholesterol (HDL-C) metabolism, and thus HDL; our recent work showed that deficiency of APOA1 increases bone marrow adiposity in mice. We found that ApoA1 deficient mice have greatly elevated adipocytes within their bone marrow compared to wild type counterparts. Morphologically, the increased adipocytes were similar to white adipocytes, and displayed proximal tibial-end localization. Marrow adipocytes from wild type mice were significantly fewer and did not display bone-end distribution pattern. The mRNA levels of the brown/beige adipocyte-specific markers Ucp1, Dio2, Pat2, Pgc1a, and the expression of leptin were greatly reduced in the ApoA1 knock-out in comparison to the wild-type mice. In the knock-out mice adiponectin was remarkably elevated. In keeping with the close ties of hematopoietic stem cells and marrow adipocytes, we found that the elevated adiposity in the ApoA1 knock out mice is associated with a significant reduction of the hematopoietic stem cells and common myeloid, but not common lymphoid, progenitors. Moreover, the “beiging”-related marker osteopontin and the angiogenic factor VEGF were also reduced in the ApoA1 knock-out mice, further supporting the notion that APOA1, and most probably HDL-C, regulate bone marrow microenvironment, favouring beige/brown adipocyte characteristics.
REVIEW | doi:10.20944/preprints202308.0491.v1
Subject: Engineering, Bioengineering Keywords: Extracellular matrix; Cell-tissue interactions; Tissue engineering; Regenerative medicine; scaffolds
Online: 7 August 2023 (07:26:41 CEST)
The advancements achieved in Tissue Engineering are based on a careful and in-depth study of cell-tissue interaction. The choice of a certain biomaterial in Tissue Engineering is fundamental as it represents an interface for adherent cells in the creation of a microenvironment suitable for cell growth and differentiation. The knowledge of the biochemical and biophysical properties of the extracellular matrix is a useful tool for the optimization of polymeric scaffolds. The aim of this re-view is to analyse the chemical, physical and biological parameters on which it is possible to act in Tissue Engineering for the optimization of polymeric scaffolds. Understanding the scaffold impact on cell fate is of paramount importance for the successful advancement of Tissue Engineering.
REVIEW | doi:10.20944/preprints202309.0501.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: Epicardial Adipose Tissue; Pericoronary Adipose Tissue; Coronary Inflammation; Acute Coronary Syndromes.
Online: 7 September 2023 (10:14:44 CEST)
Vascular inflammation is recognized as the primary trigger of acute coronary syndrome (ACS). However, current noninvasive methods are not capable of accurately detecting coronary inflammation. Epicardial adipose tissue (EAT) and pericoronary adipose tissue (PCAT), in addition to their role as an energy reserve system, have been found to contribute to the development and progression of coronary artery calcifica-tion, inflammation, and plaque vulnerability. They also participate in the vascular re-sponse during ischemia, sympathetic stimuli, and arrhythmia. As a result, the evalua-tion of EAT and PCAT using imaging techniques such as computed tomography (CT), cardiac magnetic resonance (CMR), and nuclear imaging has gained significant atten-tion. PCAT-CT attenuation, which measures the average CT attenuation in Hounsfield units (HU) of the adipose tissue, reflects adipocyte differentiation/size and leukocyte infiltration. It is emerging as a marker of tissue inflammation and has shown prognos-tic value in coronary artery disease (CAD), being associated with plaque development, vulnerability, and rupture. In patients with acute myocardial infarction (AMI), an in-flammatory pericoronary microenvironment promoted by dysfunctional EAT/PCAT has been demonstrated, and more recently, it has been associated with plaque rupture in non-ST-segment elevation myocardial infarction (NSTEMI). Endothelial dysfunc-tion, known for its detrimental effects on coronary vessels and its association with plaque progression, is bidirectionally linked to PCAT. PCAT modulates the secretory profile of endothelial cells in response to inflammation and also plays a crucial role in regulating vascular tone in the coronary district. Consequently, dysregulated PCAT has been hypothesized to contribute to type 2 myocardial infarction with non-obstructive coronary arteries (MINOCA) and coronary vasculitis. Recently, quan-titative measures of EAT derived from coronary CT angiography (CCTA) have been included in artificial intelligence (AI) models for cardiovascular risk stratification. These models have shown incremental utility in predicting major adverse cardiovas-cular events (MACE) compared to plaque characteristics alone. Therefore, the analysis of PCAT and EAT, particularly through PCAT-CT attenuation, appears to be a safe, valuable, and sufficiently specific noninvasive method for accurately identifying cor-onary inflammation and subsequent high-risk plaque. These findings have been sup-ported by biopsy and in vivo evidence. Although speculative, these pieces of evidence open the door to a fascinating new strategy in cardiovascular risk stratification. The incorporation of PCAT and EAT analysis, mainly through PCAT-CT attenuation, could potentially lead to improved risk stratification and guide early targeted primary pre-vention and intensive secondary prevention in patients at higher risk of cardiac events.
ARTICLE | doi:10.20944/preprints202106.0545.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bone tissue regeneration; injectable; bone graft; fracture; osteoblast; bone tissue engineering
Online: 22 June 2021 (14:22:33 CEST)
The occurrence of bone-related disorders and diseases has increased dramatically in recent years around the world. Demineralized bone matrix (DBM) has been widely used as a bone implant due to its osteoinduction and bioactivity. However, the use of DBM is limited because it is a particulate material, which makes it difficult to manipulate and implant with precision, in addition, these particles are susceptible to migrate to other sites. To address this situation, DBM is commonly incorporated into a variety of carriers. An injectable scaffold has advantages over bone grafts or preformed scaffolds, such as the ability to flow and fill the bone defect. The aim of this research is to develop a DBM carrier with such viscoelastic properties to obtain an injectable bone substitute (IBS). The DBM carrier developed consisted of a PVA/glycerol network cross-linked with borax and reinforced with CaCO3 as a pH neutralizer, porosity generator, and source of Ca. The physicochemical properties were determined by the injectability test, FTIR, SEM, and TGA. Porosity, degradation, bioactivity, possible cytotoxic effect, and proliferation in osteoblasts were also determined. The results show that the developed material has great potential to be used in bone tissue regeneration
REVIEW | doi:10.20944/preprints202010.0620.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Bioprinting; Bioinks; Tissue engineering
Online: 29 October 2020 (14:50:51 CET)
Bioprinting is a relatively new yet evolving technique predominantly used in regenerative medicine and tissue engineering. 3D bioprinting techniques combine the advantages of creating Extracellular Matrix (ECM) like environments for cells and computer-aided tailoring of predetermined tissue shapes and structures. The essential application of bioprinting is for the regeneration or restoration of damaged and injured tissues by producing implantable tissues and organs. The capability of bioprinting is yet to be fully scrutinized in sectors like the patient-specific spatial distribution of cells, bio-robotics, etc. In this review, currently developed experimental systems and strategies for the bioprinting of different types of tissues as well as for drug delivery and cancer research are explored for potential applications. This review also digs into the most recent opportunities and future possibilities for the efficient implementation of bioprinting to restructure medical and technological practices.
REVIEW | doi:10.20944/preprints202311.1109.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: Intermittent Cold Exposure; ICE; cold exposure; adipose tissue; brown adipose tissue; beiging
Online: 16 November 2023 (13:12:10 CET)
Intermittent cold exposure has garnered increased attention in popular culture, largely for its proposed effects on mood and immune function, but there are also suggestions that the energy wasting mechanisms associated with thermogenesis may decrease body weight and fat mass. Considering the continued and worsening prevalence of obesity and type II diabetes, any protocol that can reduce body weight and/or improve metabolic health would be a substantial boon. Here, we present a narrative review exploring the research related to ICE and adipose tissue. Any publicly available original research examining the effects of repeated bouts of ICE with adipose related outcomes was included. While ICE does not consistently lower bodyweight or fat mass, there does seem to be evidence for ICE as a positive modulator of the metabolic consequences of obesity, such as glucose tolerance and insulin signaling. Further, ICE consistently increases the activity of brown adipose tissue (BAT) and transitions white adipose tissue to a phenotype more in line with BAT. Lastly, the combined effects of ICE and exercise do not seem to provide any additional benefit, at least when exercise is done during ICE bouts. The majority of the current literature on ICE is based in rodent models where animals are housed in cold rooms, which does not reflect protocols likely to be implemented in humans such as cold-water immersion. Future research could specifically characterize ICE via cold water immersion in combination with controlled calorie intake to clearly determine the effects of ICE as it would be implemented in humans looking to lower bodyweight via reductions in fat mass.
REVIEW | doi:10.20944/preprints202306.0515.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: epigenetic; genomic imprinting; ovarian tissue cryopreservation; testicular tissue cryopreservation; Medically Assisted Reproduction
Online: 7 June 2023 (08:32:11 CEST)
Ovarian tissue cryopreservation (OTC) or testicular tissue cryopreservation (TTC) are effective and often the only options for fertility preservation in female or male patients due to oncological, medical, or social aspects. While TTC and resumption of spermatogenesis, either in vivo or in vitro, has still be considered an experimental approach in humans, OTC and autotransplantation has been applied increasingly to preserve fertility with more than 200 live births worldwide. However, the cryopreservation of reproductive cells followed by the resumption of gametogenesis, either in vivo or in vitro, may interfere with sensitive and highly regulated cellular processes. In particular, the epigenetic profile, which includes not just reversible modifications of the DNA itself but also post-translational histone modifications, small non-coding RNAs, gene expression and availability, and storage of related proteins or transcripts, have to be considered in this context. Due to complex reprogramming and maintenance mechanisms of the epigenome in germ cells, growing embryos, and offspring, OTC and TTC are carried out at very critical moments early in the life cycle. Given this background, the safety of OTC and TTC taking into account the epigenetic profile has to be clarified. Cryopreservation of mature germ cells (including Metaphase II oocytes and mature spermatozoa collected via ejaculation or more invasively after testicular biopsy) or embryos has been used successfully for many years in Medically Assisted Reproduction (MAR). However, tissue freezing followed by in vitro or in vivo gametogenesis has become more attractive in the past, while few human studies have analysed the epigenetic effects, with most data deriving from animal studies. In this review, we highlight the potential influence of the cryopreservation of immature germ cells and subsequent in vivo or in vitro growth and differentiation on the epigenetic profile in humans and animals.
ARTICLE | doi:10.20944/preprints201611.0121.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tissue microarray; immunohistochemistry; cancer imaging; tyrosine kinase receptor; normal tissue; colon cancer
Online: 24 November 2016 (11:07:23 CET)
Targeted image-guided oncologic surgery (IGOS) relies on the recognition of cell surface-associated proteins, which should be abundantly present on the tumor cells but preferably absent on cells in surrounding healthy tissue. The transmembrane receptor tyrosine kinase EphA2, a member of the A class of the Eph receptor family, has been reported to be highly overexpressed in several tumor types including breast, lung, brain, prostate, and colon cancer, and is considered amongst the most promising cell membrane-associated tumor antigens by the NIH. Another member of the Eph receptor family belonging to the B class, EphB4, has also been found to be up-regulated in multiple cancer types. In this study, EphaA2 and EphB4 are evaluated as target for IGOS of colorectal cancer by immunohistochemistry (IHC) using a tissue microarray (TMA) consisting of 168 pairs of tumor and normal tissue. The IHC sections were scored for staining intensity and percentage of cells stained. The results show a significantly enhanced staining intensity and more widespread distribution in tumor tissue compared with adjacent normal tissue for EphA2 as well as EphB4. Based on its more consistently higher score in colorectal tumor tissue compared to normal tissue, EphB4 appears to be an especially promising candidate for IGOS of colorectal cancer.
ARTICLE | doi:10.20944/preprints202309.0742.v1
Subject: Biology And Life Sciences, Aging Keywords: aging; angiogenesis; elderly; ischemia; microRNA; myocardial infarction; thymus adipose tissue; subcutaneous adipose tissue
Online: 12 September 2023 (07:09:18 CEST)
Adult human thymus degenerates into adipose tissue (TAT). In contrast to subcutaneous adipose tissue (SAT), TAT has been reported to exhibit enhanced angiogenic properties in elderly people. We have previously shown that vascular endothelial growth factor A (VEGFA) is the most abundant angiogenic growth factor in TAT of patients with ischemic cardiomyopathy (IC), and that VEGFA levels are increased in elderly (>70 years) compared with middle-aged patients. This makes TAT a promising candidate for angiogenic therapies and the regeneration of ischemic tissues following coronary surgery. MicroRNAs (miRNAs) have emerged as attractive therapeutic targets, especially those that regulate angiogenic processes. The study's purpose is to determine the miRNA network associated with both VEGFA pathway regulation and enrichment of age-linked angiogenesis in the TAT.
REVIEW | doi:10.20944/preprints202012.0220.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: chromatography; amino acids; fatty acids; pork analysis; adipose tissue; muscle tissue; nutritional factors.
Online: 9 December 2020 (11:14:18 CET)
The increasing demand for high-quality livestock products dictates to develop approaches to assessing the composition of the fatty acids (CFAs) and amino acids (CAAs) in animal tissues. The review considers the following issues: chromatographic methods for the determination of CAAs and CFAs of pig tissues; factors influencing the CAAs and CFAs of pig tissues; methods of regulating CAAs and CFAs of pork using nutritional factors; the effect of CAAs and CFAs on formation of meat properties. The main methods for determining CAAs or CFAs are the ion-exchange or gas chromatography, respectively. The total FA amount and individual FAs have significant effects on the tenderness, taste, color and juiciness of pork meat (due to the different melting points of particular fatty acids, formation of lipid oxidation products during cooking, etc.). Muscle proteins of pigs with regulated fatness differ also in CAAs (decreasing by increase in “pork fat” and decrease in the protein’s amount. The significance of this review is also determined by high popularity of pork in Russia and in a number of other countries of the world.
ARTICLE | doi:10.20944/preprints202311.0687.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: Metformin; tendon injury; scar tissue
Online: 10 November 2023 (11:06:59 CET)
Tendon injuries, while prevalent, present a significant challenge in fully restoring their structural and functional integrity. Utilizing alpha-smooth muscle actin (α-SMA)-Ai9-scleraxis (Scx)-green fluorescent protein (GFP) transgenic mice, which exhibit both Scx (a tendon cell marker) and α-SMA (a myofibroblast marker), we explored Met's effects on tendon healing and repair and its mechanisms of action. Our findings revealed that intraperitoneal (IP) injections of Met -administered before or after injury, as well as both - effectively prevent the release of HMGB1 into the tendon matrix and reduce circulating levels of HMGB1. Additionally, Met treatment increased and activated AMPK and suppressed TGF-β1 levels within the healing tendon. These interventions also improved tendon healing by blocking the migration of α-SMA+ myofibroblasts, reducing the prevalence of disorganized collagen fibers and collagen type III, and enhancing the presence of collagen type I. These outcomes highlight Met's anti-fibrotic properties on acutely injured tendons and suggest its potential for repurposing as a therapeutic agent to minimize scar tissue formation in tendon injuries, which could have profound implications in clinical practice.
ARTICLE | doi:10.20944/preprints202103.0512.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Endurance training; angiogenesis; cardiac tissue
Online: 22 March 2021 (10:49:50 CET)
Exercise can ameliorate cardiovascular dysfunctions in diabetes condition, but its precise molecular mechanisms have not been entirely understood. The aim of the present study was to determine the impact of endurance training on expression of angiogenesis-related genes in cardiac tissue of diabetic rats. Thirty adults male Wistar rats were randomly divided into three groups (N=10) including diabetic training (DT), sedentary diabetes (SD), and sedentary healthy (SH) in which diabetes was induced by a single dose of streptozotocin (30 mg/kg). Endurance training (ET) with moderate-intensity was performed on a motorized treadmill for six weeks. Training duration and treadmill speed were increased during five weeks, but they were kept constant at the final week and slope was zero at all stages. Real-time polymerase chain reaction (RT- PCR) analysis was used to measure the expression of myocyte enhancer factor-2C (MEF2C), histone deacetylase-4 (HDAC4) and Calmodulin-dependent protein kinase II (CaMKII) in cardiac tissues of the rats. Our results demonstrated that six weeks of ET increased gene expression of MEF2C significantly (P<0.05), and caused a significant reduction in HDAC4 and CaMKII gene expression in the DT rats compared to the SD rats (P<0.05). We concluded that moderate-intensity ET could play a critical role in ameliorating cardiovascular dysfunction in a diabetes condition by regulating the expression of some angiogenesis-related genes in cardiac tissues.
ARTICLE | doi:10.20944/preprints202101.0432.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: skeletal muscle; adipose tissue; aging
Online: 22 January 2021 (08:40:26 CET)
We have previously demonstrated that the acute ingestion of essential amino acids may augment net protein balance in the elderly. Using a double blind, randomized controlled trial, our objective was to compare an experimental meal replacement enriched with essential amino acids (EMR) compared to a commercial meal replacement (Optifast®) provided once/day (q.d.) for four weeks on body composition and physical function in older, obese participants. Twenty-seven individuals (69±5 yrs; body mass index of 32±4 kg/m2) were randomly assigned to EMR (n=13) or Optifast® (n=15) supplementation. Measurements of body composition, skeletal muscle cross-sectional area (CSA), intrahepatic lipid and physical function were completed pre- and post-supplementation. Body mass, fat mass, and visceral fat mass were reduced with EMR but not altered with Optifast®. Thigh muscle CSA increased ( 4.1 ± 1.9 cm2, P = 0.03) with EMR but not Optifast®. There was a significant increase in the distance covered during the six-minute walk test with EMR ( 21±26 m) but no change in Optifast® ( 22±54 m). Improvements in body composition and physical function support the efficacious use of EMR-based meal replacements in the obese elderly.
ARTICLE | doi:10.20944/preprints202211.0366.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: Silk Fibroin; Sil-MA; 3D Printing; Additive Manufacturing; Tissue Engineering; Bioprinting; Bone Tissue Engineering
Online: 21 November 2022 (03:36:19 CET)
Methacrylated silk (Sil-MA) is a chemically modified silk fibroin specifically designed to be crosslinkable under UV light. This allows the structuring of this material throught additive manufacturing techniques and then to easily prototype patient specific construct. In this study we used Sil-MA to produce single layer crosslinked structures that can be withdrawal and ejected recovering their shape after rehydration. A complete chemical and physical characterization of the material has been conducted. Additionally, we tested the material biocompatibility according to the International Standard Organization protocols (ISO 10993) ensuring the possibility to use it in future trials. The material was also tested to verify its ability to support the osteogenesis. Two different additive manufacturing techniques have been tested (a Digital Light Processing (DLP) UV projector and a pneumatic extrusion technique) to develop Sil-MA grid. Finally, we provide a proof-of-concept that the printed Sil-MA structures are injectable.
ARTICLE | doi:10.20944/preprints202106.0707.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tissue spectroscopy; tissue optical properties; scattering coefficient; absorption coefficient; DNA content; blood content; pigment detection
Online: 29 June 2021 (12:57:34 CEST)
The knowledge of the optical properties of biological tissues in a wide spectral range is highly important for the development of noninvasive diagnostic or treatment procedures. The absorption coefficient is one of those properties, from which various information about tissue components can be retrieved. Using transmittance and reflectance spectral measurements acquired from ex vivo rabbit brain cortex samples, allowed to calculate its optical properties in the ultraviolet to the near infrared spectral range. Melanin and lipofuscin, the two pigments that are related to the ageing of tissues and cells were identified in the cortex absorption. By subtracting the absorption of these pigments from the absorption of the brain cortex, it was possible to evaluate the true ratios for the DNA/RNA and hemoglobin bands in the cortex – 12.33 fold (at 260 nm), 12.02 fold (at 411 nm) and 4.47 fold (at 555 nm). Due to the fact that the accumulation of melanin and lipofuscin increases with the ageing of the brain tissues and are related to the degeneration of neurons and their death, further studies should be performed to evaluate the evolution of pigment accumulation in the brain to prevent the development of Alzheimer, Parkinson and stroke pathologies in the brain.
REVIEW | doi:10.20944/preprints202310.1589.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Pectin; Tissue Engineering; Composites; Biomedical Applications
Online: 25 October 2023 (08:11:48 CEST)
Due to its distinctive chemical and biological properties, pectin has recently drawn much attention in biomedical and tissue engineering applications. Polymers like pectin with cell-instructive properties are attractive natural biomaterials for tissue repair and regeneration. Besides, bioactive pectin and pectin-based composites exhibit improved characteristics to deliver active molecules. Pectin and pectin-based composites serve as interactive matrices or scaffolds by stimulating cell adhesion and cell proliferation and enhancing tissue remodeling by forming an extracellular matrix in vivo. Several bioactive properties, such as immunoregulatory, antibacterial, anti-inflammatory, anti-tumor, and antioxidant activities, contribute to the pectin's and pectin-based composite's enhanced applications in tissue engineering and drug delivery systems.This paper reviews the promising characteristics of pectin or pectic polysaccharides and highlights its potential applications in drug delivery and tissue engineering. Tissue engineering scaffolds containing pectin and pectin-based conjugates or composites demonstrate essential features such as non-toxicity, tunable mechanical properties, biodegradability, and suitable surface properties. The design and fabrication of pectic composites are versatile for tissue engineering and drug delivery applications.
ARTICLE | doi:10.20944/preprints202306.1507.v1
Subject: Biology And Life Sciences, Toxicology Keywords: Imidacloprid; Goldfish; Metabolites; Tissue Distribution; Toxicity
Online: 21 June 2023 (08:57:58 CEST)
Imidacloprid is the first-generation neonicotinoid insecticide. But, the long-term use of im-idacloprid as a pesticide has caused severe water pollution. Recently, the toxicity of imidacloprid to aquatic organisms has received increasing attention. This study aimed to investigate the ab-sorption and distribution of imidacloprid in various tissues (gills, intestine, liver, muscle, brain, and gonads) of goldfish through short-term and continuous exposure tests for 28 days. The re-sults of short-term exposure indicated that the concentration of imidacloprid and its metabolites in tissues at the transfer stage decreased steadily after 1 day of 40 mg/l imidacloprid water treatment and was below the detection limit after 3 days. Continuous exposure for 28 days at various treatment concentrations showed that the concentrations of imidacloprid and its metab-olites differed significantly among the different tissues of the goldfish. In the 20 mg/l treatment group (S1), the highest concentration of imidacloprid was found in the liver (12.04 μg /gtissue), followed by the intestine (9.91 μg /gtissue), muscle (6.20 μg /gtissue), gill (6.11 μg /gtissue), gonads (5.22 μg /gtissue), and brain (2.87 μg /gtissue). In the 40 mg/l treatment group (S2), the order of tissue concentrations was similar to that of the S1 group, with the highest concentration observed in the liver (12.04 μg/gtissue), followed by the intestine (9.91 μg/gtissue), muscle (6.20 μg/gtissue), gill (6.11 μg/gtissue), gonads (5.22 μg/gtissue), and brain (2.87 μg/gtissue). Fur-thermore, the study detected 5-hydroxyimidacloprid, imidacloprid urea, and 6-chloronicotinic acid in imidacloprid metabolites in all tissues, while imidacloprid was detected only in the intes-tine and liver. Overall, the results of this study contribute to a better understanding of the met-abolic behavior of imidacloprid in organisms and provide new data to support the assessment of imidacloprid toxicity in fish.
ARTICLE | doi:10.20944/preprints202305.1813.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: rh-BMP2; Ki67-Proliferation – Gingival Tissue
Online: 25 May 2023 (14:36:37 CEST)
Bone morphogenetic proteins (BMPs), belonging to the transforming growth factor-β superfamily, regulate many cellular activities including proliferation and neovascularization. The use of recombinant human bone morphogenic protein 2 (rh-BMP 2) in oral and maxillofacial surgery has seen a tremendous increase, especially with bone grafting materials to promote bone reconstruction processes; even though its interactions with the other essential processes in the human tissues are still not fully clear. investigating the effect of administrating rh-bmp2 on the clinical values of the gingival cell proliferation index Ki67 marker expression in the gingival tissue in comparison with normal human gingival tissue. The study includes 2 groups in a randomized controlled Clinical Trial: 40 gingival samples; 20 normal and 20 have been treated with 0.25µg of rh-BMP2 during dental implantation in the posterior mandible area, taken 3 months later in the time of healing abutments installation using a tissue puncher. Samples will be stained with hematoxylin-eosin and immunohistochemically. The expression of Ki67 will be measured in one way: the number of cells that express the marker. The comparison between groups will be done using One -a way ANOVA test in the numerical data SPSS 17.0 will be used as software. Differences would be considered significant at P=0.05. It is considered that rh-BMP2 can improve gingival tissue proliferation in patients undergoing dental implant treatment, and indicates better healing.
REVIEW | doi:10.20944/preprints202302.0223.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: Obesity; Hyperpalatability; Adipose tissue; Hormonal imbalance
Online: 14 February 2023 (02:17:02 CET)
Obesity is characterized by surplus buildup of body lipids primarily in adipose tissue. Prevalence and incidence of obesity are ascending persistently at an alarming rate. Unusual eating behaviors like compulsion to eat (food addiction) and excessive consumption are the premier contributors to obesity. Both are under influence of a variety of stimuli, mainly being stress, emotions, dietary restrictions, sweetness, hyperpalatability, neural pathways, hormonal imbalance and genetics. This review summarizes the potential driving factors behind overeating and food addiction for understanding and exploring obesity linked novel agents and processes as an endeavor to advance treatment approaches. Obesity has been studied extensively throughout the world due to high incidence and association with several metabolic disorders including cardiovascular disorders. The food addition has considered one of potential key factor of obesity and excessive weight gain. Sedentary life style and availability of food also induce obesity.
ARTICLE | doi:10.20944/preprints202009.0531.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: polystyrene; tissue culture; cell membrane stability
Online: 23 September 2020 (03:46:57 CEST)
Unanticipated errors in scientific research data can be attributed to the unwarranted assumption of uniformity in the polystyrene surface that is ubiquitously used in tissue culture flasks and dishes. We have shown that when adherent cells are subjected to fluid shear force, equivalent to rinsing the culture with a balanced salt solution, cells on some areas of the polystyrene surface will immediately rupture while still adherent on the surface. This heterogeneity on the polystyrene surface can cause unexpected variability in experimental results and in replicating experiments among labs. In this paper a novel quantitative method is described to measure the degree of heterogeneity on the polystyrene surface of tissue culture flasks. The results show significant variation among several brands of tissue culture flasks as well as large variability within the production lot of a manufacturer. The assay method involves loading the cells with a fluorescent marker that is released upon membrane rupture. Cell membrane rupture also causes the loss of marker proteins used in Westernblots. This novel assay method can be used to monitor the batch consistency and the manufacturing process of flasks and dishes. It may also be used to test new biomaterials.
ARTICLE | doi:10.20944/preprints202002.0315.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: COVID-19; adipose tissue; cancer; ACE2
Online: 23 February 2020 (10:30:06 CET)
The spread of 2019 novel coronavirus disease (COVID-19) throughout the world has been a severe challenge for public health. The human angiotensin-converting enzyme 2 (ACE2) has a remarkably high affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). By the search for network database and re-analysis of pubic data, we found the level of ACE2 expression in adipose tissue was higher than that in lung tissue, which indicated the adipose tissue might be vulnerable to SARS-CoV-2 as well; the levels of ACE2 expressed by adipocytes and adipose progenitor cells were similar between non-obese individuals and obese individuals, but obese individuals have more adiposes so as to increase the number of ACE2-expressing cells; the expression of ACE2 in tumor tissues posed by five different types of cancers increased significantly compared with that in adjacent tissues. Thus, we suggest that more attentions might be given to obese individuals and the five types of cancer patients during the outbreak of COVID-19.
ARTICLE | doi:10.20944/preprints201901.0116.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Adipose tissue, Bioavailable, Menthol, Topical, TRPM8.
Online: 11 January 2019 (15:47:35 CET)
Recent evidences support a role of menthol, a TRPM8 agonist, in enhanced energy expenditure, thermogenesis and BAT-like activity in classical WAT depots in TRPM8 dependent and independent manner. The present study was designed to analyze whether oral and topical administration of menthol is bioavailable at subcutaneous adipose tissue and is sufficient to induce desired energy expenditure effects directly. GC-FID was performed to study menthol bioavailability in serum and subcutaneous white adipose tissue following oral and topical administration. Further, 3T3L1 adipocytes were treated with bioavailable menthol doses and different parameters (lipid accumulation, “browning/brite” and energy expenditure gene expression, metal analysis, mitochondrial complex’s gene expression) were studied. No difference was observed in serum levels but significant difference was seen in the menthol concentration on subcutaneous adipose tissues after oral and topical application. Menthol administration at bioavailable doses significantly increased “browning/brite” and energy expenditure phenotype, enhanced mitochondrial activity related gene expression, increased metal concentration but didn’t alter the lipid accumulation. Further, we used pharmacological antagonism based approach to study the TRPM8 involvement in menthol effect. In conclusion, the present study provides an evidence that bioavailable menthol after single oral and topical administration is sufficient to induce “brite” phenotype in subcutaneous adipose tissue.
ARTICLE | doi:10.20944/preprints201703.0226.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: hydroxyapatite; xenografts; physicochemical-characterization; tissue reaction
Online: 31 March 2017 (08:35:07 CEST)
Detailed information about graft material characteristic is crucial to evaluate their clinical outcomes. The present study evaluates the physicochemical characteristics of two xenografts manufactured on an industrial scale deproteinized at different temperatures (non-sintered and sintered) in accordance with a protocol previously used in sinus lift procedures. It compares how the physico-chemical properties influence the material performance in vivo with a histomorphometric study in retrieved bone biopsies following maxillary sinus augmentation, in 10 clinical cases. X-ray diffraction analysis revealed typical structure of hydroxyapatite for both materials. Both xenografts are porous and exhibit intraparticle pores. Strong differences were observed in terms of porosity, cristallinity, and calcium/phosphate. Histomorphometric measurements on the bone biopsies showed statistically significant differences. The physicochemical assessment of both xenografts in accordance with the protocol developed at industrial scale confirmed that these products present excelent biocompatibilitity, with characteristics similar to natural bone. The sintered HAs xenograft exhibit higher osteoconductivity although were not complete resorbable (30.80±0.88% residual material). On the other hand, the non-sintered HAs xerograft induced about 25.92±1.61% of new bone and almost complete degradation after 6 months implantation. Differences in physico-chemical characteristics found between the two HAs xenograft determine different behavior of this material.
ARTICLE | doi:10.20944/preprints202309.1333.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: dental implant; implant surgery; soft tissue management; immediate implant placement; early implant placement; connective tissue graft
Online: 19 September 2023 (16:29:43 CEST)
The clinical requirement for a good esthetic result for immediate implant placement is the absence of dehiscence in the anterior facial alveolar bone. In the presence of a dehiscence, it is recommend-ed to use a connective tissue graft in addition to immediate implant placement or to change to ear-ly implant placement. However, the literature focusing on dehiscence is scarce, and the influence of different placement times and combined use of connective tissue graft on postoperative esthetics in cases with dehiscence is unclear. Therefore, we quantitatively evaluated the pre-extraction de-hiscence morphology and postoperative changes in the facial tissue of implants in three groups: immediate implant placement (Group I), immediate implant placement with connective tissue graft (Group IC), and early implant placement (Group E). Fifty-two implants were obtained (20 in Group I, 16 in Group IC, and 16 in Group E). A wider dehiscence increases the risk of soft tissue regression, which was one reason for choosing early implant placement. A combination of imme-diate implant placement and connective tissue graft, or early implant placement, tended to result in less soft tissue regression due to the thicker postoperative facial soft tissue volume.
REVIEW | doi:10.20944/preprints202005.0460.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: extracellular vesicles; exosomes; neural tissue repair; neuroregeneration; non-human primates; hydrogels; neural tissue engineering; stroke; cortical injury
Online: 28 May 2020 (13:08:32 CEST)
Neural tissue engineering, nanotechnology and neuroregeneration are diverse biomedical disciplines that have been working together in recent decades to solve the complex problems linked to central nervous system (CNS) repair. It is known that the CNS demonstrates a very limited regenerative capacity because of a microenvironment that impedes effective regenerative processes, making development of CNS therapeutics challenging. Given the high prevalence of CNS conditions such as stroke that damage the brain and place a severe burden on afflicted individuals and on society, it is of utmost significance to explore the optimum methodologies for finding treatments that could be applied to humans for restoration of function to pre-injury levels. Extracellular vesicles (EVs), also known as exosomes, when derived from mesenchymal stem cells, are one of the most promising approaches that have been attempted thus far, as EVs deliver factors that stimulate recovery by acting at the nanoscale level on intercellular communication while avoiding the risks linked to stem cell transplantation. At the same time, advances in tissue engineering and regenerative medicine have offered the potential of using hydrogels as bio-scaffolds in order to provide the stroma required for neural repair to occur, as well as the release of biomolecules facilitating or inducing the reparative processes. This review introduces a novel experimental hypothesis regarding the benefits that could be offered if EVs were to be combined with biocompatible injectable hydrogels. The rationale behind this hypothesis is presented, analyzing how a hydrogel might prolong the retention of EVs and maximize the localized benefit to the brain. This sustained delivery of EVs would be coupled with essential guidance cues and structural support from the hydrogel until neural tissue remodeling and regeneration occur. Finally, the importance of including non-human primate (NHP) models in the clinical translation pipeline, as well as the added benefit of multi-modal neuroimage analysis to establish non-invasive, in vivo, quantifiable imaging-based biomarkers for CNS repair are discussed, aiming for more effective and safe clinical translation of such regenerative therapies to humans.
ARTICLE | doi:10.20944/preprints202307.1410.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: mantle tissue; novel toxin; scallop; small intestine
Online: 20 July 2023 (10:22:45 CEST)
We previously showed that feeding mice a diet containing 1% mantle tissue decreased food consumption, leading to death. We also isolated and identified toxic substances in the mantle tissue. In the present study, we investigated the characteristics and stability of mantle tissue toxicity. Treatment of mantle tissue with 1 mM HCl, 1 mM NaOH, 1 mM dithiothreitol, and 1 mM H2O2 and heating did not reduce the toxicity of mantle tissue in mice. These results suggest that mantle toxins are stable in tissues, particularly when exposed to acidic and digestive enzymes. We examined whether mantle tissue exhibited acute toxicity. Diets containing 1% and 20% mantle extract showed similar levels of toxicity, demonstrating that feeding of mantle tissue does not lead to acute toxicity. Finally, we examined the toxicity of the mantle tissue against small intestinal tissue. Chronic feeding of mantle tissue to mice changed the color of the small intestine. Real-time PCR analysis showed that mantle tissue feeding caused changes of inflammation and endoplasmic reticulum stress markers in the small intestine. These results suggest that feeding of mantle tissue causes toxicity after causing initial damage to the small intestinal tissue.
REVIEW | doi:10.20944/preprints202307.0999.v2
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: prostate cancer; metastasis; tissue-based genomic biomarker
Online: 18 July 2023 (07:17:24 CEST)
Background: The incidence of prostate cancer (PC) has been risen annually. Despite the diagnosis is made mainly with non-metastatic PC, mortality is explained by the metastatic disease (mPC). Without a doubt there is an intermediate scenario in which patients have no mPC but will have initiated a metastatic cascade through an epithelial-mesenchymal transition. There is indeed a need for more and better tools to predict what patients will progress in the future to non-localized clinical disease or already have micrometastatic disease, and therefore, will clinically progress after primary treatment. Biomarkers for predicting mPC are still under development; there are few studies and not much evidence of their usefulness. Summary: This review is focused on tissue-based genomic biomarkers (TBGB) for predicting metastatic disease. We developed four main research questions that will attempt to answer according to the current evidence. Why is important to predict metastatic disease? Which tests are available to predict metastatic disease? What impact should there be on clinical guidelines and clinical practice in predicting metastatic disease? What are current prostate cancer treatments? Key Messages: Knowing useful predict tools could help determine which patients may need multimodal or adjuvant treatment even with a localized disease, and in consequence, what patients do not need more than a single modality of treatment. The importance of predicting metastasis is fundamental, given that once metastasis is diagnosed, the quality of life (QoL) and survival drop dramatically.
ARTICLE | doi:10.20944/preprints202307.0236.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: fibroblasts; endothelial cell; differentiation; tissue engineering; matrigel
Online: 5 July 2023 (08:38:25 CEST)
The role of mesenchymal-to-endothelial transition in the angiogenic response is controversial. Toward this, the present study aimed to determine if fibroblasts contribute to angiogenesis. Endothelial differentiation of fibroblasts was induced by culturing MRC-5 cells (human fetal lung fibroblast cells) on top of Matrigel hydrogel or embedded inside the hydrogel. The formation of ca-pillary-like networks in response to angiogenic signals was observed. The tube formation occurs quickly and can be visualized us-ing a phase-contrast inverted microscope, and/or the cells can be treated with DAPI before the assay and tubes can be visualized through fluorescence or confocal microscopy. Furthermore, fibroblasts cultured in a higher concentration invaded the Matrigel hydrogel and formed stem-cell-like spheroids. These spheroids embedded in matrigel matrices of varying densities sprouted to form 3D connective-tissue networks. Collectively, our results highlight the endothelial differentiation capacity of human lung fibroblasts. The results obtained in this work may have an impact on the search for alternative cell sources for vascular tissue engineering and the overcome of obstacles to vascularization of autologous tissue-engineered constructs and the production of functional grafts for clinical use.
ARTICLE | doi:10.20944/preprints202305.1695.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Industry; micropropagation; plant tissue culture; Sri Lanka
Online: 24 May 2023 (04:53:43 CEST)
Lack of reliable information on PTC industry in Sri Lanka is hampering the advancement of the technology. Hence, this study attempted to assess the current status of PTC industry in Sri Lanka in order to ascertain the type and the level of interventions needed to broaden the horizons of the industry. Data of last 05 years were collected through qualitative research methods including a questionnaire-based survey, personal interviews, etc. and personal interviews to identify product diversity, R&D, available facilities, production capacity, and markets. Information was analyzed qualitatively using descriptive statistical software to assess the current status, and identify gaps, challenges and opportunities. COVID pandemic and the economic crisis had a heavy toll on the PTC industry. Six major challenges experienced by business owners were identified as increasing capacity, opportunities to build market linkages, demand fluctuations, issues relating to awareness and insufficient support given by the government. Proper identification and screening of mother plants, determining the production capacities and marketing, knowledgeable and skilled human resources, were identified as important contributory factors for success. Development strategies identified mainly include instinctive decision making and government support. Embracing the significant trade achievements through resource reallocation, prioritization and improvisation processes at individual, family group, inter-organizational levels and across these levels need to be regulated through a responsible authority. These interpretations and recommendations of this research can be utilized both by the policy makers and public and private sector organizations for decision making purposes targeting commercial scale advancements.
REVIEW | doi:10.20944/preprints202305.1531.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Biomaterials; Hybrid Materials; Tissue Engineering; Regenerative Medicine
Online: 22 May 2023 (16:19:46 CEST)
The main purpose of tissue engineering is to fabricate and exploit engineered constructs suitable for the effective replacement of damaged tissues and organs, and able to perfectly integrate with the host’s organism without eliciting any adverse reaction. Ideally, autologous materials represent the best option, but they are often limited due to the low availability of compatible healthy tissues. So far, one therapeutic approach relies on the exploitation of synthetic materials: they exhibit good features in terms of impermeability, deformability and flexibility, but present chronic risks of infections and inflammations. Alternatively, biological materials, including naturally derived ones and acellular tissue matrices of human or animal origin, can be used to induce cells growth and differentiation, which are needed for tissue regeneration: however, this kind of materials lacks satisfactory mechanical resistance and reproducibility, affecting their clinical application. In order to overcome the above-mentioned limitations, hybrid materials, which can be obtained by coupling synthetic polymers and biological materials, have been investigated with the aim to improve biological compatibility and mechanical features. Currently, the interest in these mate-rials is growing, but the ideal ones have not been found yet. The present review aims at exploring some applications of hybrid materials, with particular mention to urological and cardiovascular fields: in the first case, the efforts to find a construct that can guarantee impermeability, mechanical resistance and patency will be herein illustrated; in the second case, the search for impermeability, hemocompatibility and adequate compliance will be been disclosed.
ARTICLE | doi:10.20944/preprints202303.0176.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: laser therapy; musculoskeletal system; tissue penetration depth
Online: 9 March 2023 (11:03:09 CET)
The choice of parameters for laser beams used in the treatment of musculoskeletal diseases is of great importance. First, to reach high penetration depths into biological tissue and, secondly, to achieve the required effects on a molecular level. The penetration depth depends on the wavelength since there are multiple light-absorbing and scattering molecules in tissue with different absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology. Penetration depths in two types of tissue (porcine skin and bovine muscle) were investigated. The transmittance of 1064 nm light through both tissue types was consistently higher than of 905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the difference vanished with increasing tissue thickness. The higher penetration was most likely due to a combination of lower absorption in hemoglobin and less scattering at larger wavelengths, and not due to absorption in melanin. Overall, differences in penetration depth were comparably small and high peak power and short pulse lengths of laser light seem to be more important to efficiently treat deep musculoskeletal diseases.
REVIEW | doi:10.20944/preprints202303.0091.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: FNDC5; Irisin; Degenerative disease; Regeneration; Tissue repair.
Online: 6 March 2023 (06:06:09 CET)
Physical activity is well-established as an important protective factor against degenerative conditions and a promoter of tissue growth and renewal. The discovery of FNDC5 as the precursor of irisin in 2012 sparked significant interest in its potential as a diagnostic biomarker and a therapeutic agent for various diseases. Clinical studies have examined the correlation between plasma irisin levels and pathological conditions using a range of assays, but the lack of reliable measurements for endogenous irisin has led to uncertainty about its prognostic/diagnostic potential as an exercise surrogate. Animal and tissue-engineering models have shown the protective effects of irisin treatment in reversing functional impairment and potentially permanent damage, but dosage ambiguities remain unresolved. This review provides a comprehensive examination of the clinical and basic studies of irisin in the context of degenerative conditions and explores its potential as a therapeutic approach in the physiological processes involved in tissue repair/regeneration.
ARTICLE | doi:10.20944/preprints202212.0074.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: tissue engineering; bone; laser; femtosecond; patterning; direct
Online: 5 December 2022 (10:26:46 CET)
Laser patterning of implant materials for bone tissue engineering purposes has shown to be a promising technique to control cell properties such as adhesion or differentiation, resulting in an enhanced osteointegration. However, the perspective of patterning the bone tissue side interface to generate microstructure effects has never been investigated. In the present study, three different laser-generated patterns were machined on the bone surface with the aim to identify the best surface morphology compatible with osteogenic-related cells recolonization. The laser patterned bone tissue was characterized by electron scanning microscopy and confocal microscopy in order to obtain a comprehensive picture of the bone surface morphology. Cortical bone patterning impact upon cell compatibility and cytoskeleton rearrangement to the patterned surfaces was performed with Stromal Cells from Apical Papilla (SCAPs). Results indicated that laser machining had no detrimental effect upon consecutively seeded cells metabolism. Orientation assays revealed that surface patterning characterized by larger hatch distances was correlated with a higher cell cytoskeletal conformation to the laser-machined patterns. For the first time, to our knowledge, bone is considered and assessed here as a potentially engineered-improvable biological interface. Further studies shall focus on in vivo implications of this direct patterning.
ARTICLE | doi:10.20944/preprints202207.0297.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Wharton's Jelly; Minimal Manipulation; Structural Tissue Defect
Online: 20 July 2022 (07:39:43 CEST)
One in four adults in the US suffer from cartilage degeneration of the Intervertebral Disc (DDD) or load bearing joints (DJD). Combined DDD and DJD leads to billions of dollars in surgical health care costs annually. Since cartilage is avascular, it has a limited regenerative capacity. Conventional non-surgical treatment modalities provide brief symptomatic relief, have sided effects, and do not address the actual structural tissue defect in the cartilage itself. As such, new alternatives are needed. Perinatal tissue allografts have emerged as a novel frontier for bio-mechanical cartilage engineering research. Birth product-specific therapeutic roles and clinical outcomes are actively being investigated. The tissues of interest include umbilical cord-derived Wharton’s Jelly (WJ). This study assessed WJ tissue samples via ZEISS Supra 55VP Field-Emission Scanning Electron Microscope (SEM) at 100 and 300nm resolution scales. The captured images of pre and post-processed structural tissue matrices in WJ allografts were analyzed against themselves and peer-reviewed SEM images of articular cartilage, intervertebral disc cartilage, and muscle fascia. SEM images of post-processed WJ structural tissue matrices were analogous to structural tissue matrices in human articular cartilage, intervertebral disc cartilage, and muscle fascia. Relevant characteristics of pre- and post-processed structural tissue matrices in WJ allografts were comparable. This is the first study, that we are aware of, to utilize SEM to compare the pre-and post-processing relevant structural characteristics of WJ allografts and additionally demonstrate that structural collagen matrices in post-processed WJ allografts are analogous in structure to the cartilage in articular joints, intervertebral discs, and muscle fascia.
ARTICLE | doi:10.20944/preprints202101.0192.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: naturally infected; hantavirus detection; urine; rodent; tissue
Online: 11 January 2021 (12:45:21 CET)
The natural hosts regarding Orthohantaviruses are rodents, soricomorphs and bats, and it is well known they may cause serious or even fatal diseases among humans worldwide. The virus is persistent among animals and it is shed via urine, saliva and feces, throughout the entirety of their lives. We aim to identify the effectiveness regarding hantavirus detection from rodent tissue samples and urine originating from naturally infected rodents. Initially, animals were trapped at five distinct locations throughout the Transdanubian region in Hungary. Lung, liver, kidney and urine samples were obtained from 163 perished animals. All organs and urine were tested using nested reverse transcriptase-polymerase chain reaction (nRT-PCR). Furthermore, sera were examined for IgG antibodies against DOBV and PUUV viruses by Western Blot assay. IgG antibodies against hantaviruses and/or nucleic acid were detected in 25 (15.3%) cases. Among Apodemus, Myodes, and Microtus rodent species, DOBV, PUUV, TULV were all clearly identified. The virus nucleic acid was detected most effectively from the kidney (100%), while only 55% of screened lung tissues were positive. Interestingly, only 3 out of 20 rodent urine samples were positive regarding nRT-PCR. Moreover, five rodents were seropositive without detectable virus nucleic acid from any of the tested organs.
ARTICLE | doi:10.20944/preprints201907.0142.v3
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: glaucoma; tissue engineering; trabecular meshwork; outflow facility
Online: 8 December 2020 (10:09:17 CET)
Glaucoma is a blinding disease largely caused by increased resistance to drainage of fluid from the eye’s anterior chamber, resulting in elevated intraocular pressure (IOP). A major site of fluid outflow regulation and pathology is the trabecular meshwork (TM) at the entrance of the eye’s drainage system. We aimed to characterize the structural and functional properties of a newly developed tissue-engineered anterior segment eye culture model. We hypothesized that repopulation of a decellularized TM with non-native TM cells could restore aspects of normal TM. The decellularization protocol removed all cells and debris while preserving the ECM. Seeded cells localized to the TM region and progressively infiltrated the meshwork ECM. Cells reached a distribution comparable to control TM after four days of perfusion culture. After a perfusion rate increase challenge, tissue-engineered cultures reestablished normal IOPs (reseeded = 13.7±0.4 mmHg, decellularized = 35.2±2.2 mmHg, p < 0.0001). eGFP expressing CrFK control cells caused a high and unstable IOP (27.0±6.2 mmHg). In conclusion, we describe a readily available, storable, and biocompatible scaffold for anterior segment perfusion culture of non-native cells. Tissue-engineered organs demonstrated similarities to native tissues and may reduce the need for scarce donor globes in outflow research.
HYPOTHESIS | doi:10.20944/preprints201909.0265.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: tissue polarity; Drosophila; epithelia; morphogenesis; cell adhesion
Online: 23 September 2019 (10:06:45 CEST)
The cell’s capacity to integrate and respond to spatial information is a crucial feature of morphogenesis and development. The Planar Cell Polarity (PCP) pathway is a signaling mechanism, widely conserved across metazoans, providing spatial orientation along the plane of an epithelium in morphogenic processes ranging from insect wing patterning to mammalian cochleae. Although the core genes involved in the PCP pathway have been molecularly identified in the 1990s, the PCP signaling mechanism remains controversial. In this article I discuss the main players and previous models of PCP signaling reported in the literature, and propose a new model. According to it PCP is established through an homophobic signal by transmembrane protein Frizzled (Fz): 1) a Fz signal in one cell repeals Fz itself in the adjacent cell, thereby generating symmetry breaking; 2) the instructive PCP signal is conveyed through Fz interaction with atypical cadherin Flamingo (Fmi). More broadly, homophobic signaling may represent a novel mechanism for cell-cell signaling of spatial information through modulation of cell adhesion rather than canonical ligand-receptor binding.
ARTICLE | doi:10.20944/preprints201903.0031.v1
Subject: Engineering, Bioengineering Keywords: Organ-on-Chip, tissue engineering, microfluidic technology
Online: 4 March 2019 (10:11:22 CET)
Organ-on-Chip is a game-changing technology born from the convergence of tissue engineering and microfluidic technology. Organ-on-Chip devices (OoCs) are expected to offer effective solutions to persisting problems in drug development and personalized disease treatments. This opinion paper surveys the current landscape in research, development, application and market opportunities for OoCs to help establishing a global and multi-stakeholder OoC ecosystem. Based on a bibliometric study, a market analysis, expert interviews, and panel discussions held at the ORCHID Vision Workshop (Stuttgart, 23 May 2018), we outline presently unmet needs, key challenges, barriers and perspectives of the field, and finally propose recommendations towards the definition of a comprehensive roadmap that could render OoCs realistic models of human (patho)physiology in the near future.
ARTICLE | doi:10.20944/preprints201901.0082.v3
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: dog; prostatic tissue; extracellular matrix; picrosirius; immunohistochemistry
Online: 21 February 2019 (06:52:00 CET)
This study aimed to investigate Coll-I, III, IV and elastin in canine normal prostate and PC, using Picrosirius red (PSR) and Immunohistochemical (IHC) analysis. Eight normal prostates and 10 PC from formalin-fixed, paraffin-embedded samples were used. Collagen fibers area was analyzed with ImageJ software. The distribution of Coll-I and Coll-III was approximately 80% around prostatic ducts and acini, 15% among smooth muscle and 5% surrounding blood vessels, in both normal prostate and PC. There was a higher median area of Coll-III in PC, when compared to normal prostatic tissue (p=0.001 for PSR and p= 0.05 for IHC). Immunostaining for Coll-IV was observed in the basal membrane of prostate acini, smooth muscle, blood vessels, and nerve fibers of normal and PC samples. Although there was no difference in Coll-IV area between normal tissue and PC, tumors with Gleason score 10 showed absence of Coll-IV, when compared to scores 6 and 8 (p=0.0095). Elastic fibers were found in the septa dividing the lobules and around the prostatic acini of normal samples, and was statistically higher in PC, compared to normal tissue (p=0.00229). Investigation of ECM components brings new information and should be correlated with prognosis in future studies.
ARTICLE | doi:10.20944/preprints201901.0073.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: Phenylbutyrate, PFKL, Obesity, UCP1, Brown adipose tissue
Online: 8 January 2019 (15:22:39 CET)
Obesity, which is characterized by an excessive accumulation of body fat, is one of the critical factors causing metabolic syndrome. Many studies have been performed to identify appropriate agents to control obesity, but toxicity remains a problem. Herein, we identified that phenylbutyrate (PBA), which has been used to treat urea cycle disorder with very low toxicity for a long time, efficiently inhibited high fat-induced body weight gain in a diet-induced obesity mouse model (DIO model). PBA treatment decreased body fat mass and increased lean composition. Moreover, PBA increased brown adipose tissue (BAT) activity by increasing glucose uptake, thereby improving glucose tolerance and insulin tolerance. Interestingly, PBA could induce the expression of phosphofructokinase (PFKL), a key enzyme in the glycolytic pathway, and knocking down PFKL dramatically repressed the expression level of Ucp1 as well as those of Prdm16, Cidea, Pgc1α, and Pparγ, which are marker genes for BAT activation. These results strongly suggested that PBA could increase energy expenditure by increasing BAT activity via the induction of PFKL. Taken together, PBA could be used as a therapeutic agent for people with obesity to prevent the development of metabolic syndrome.
REVIEW | doi:10.20944/preprints201802.0051.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: metals; dental regeneration; bioactivity; tissue regeneration; bone
Online: 6 February 2018 (05:25:46 CET)
The regeneration of bone tissue is a main purpose of most therapies in dental medicine. For bone regeneration, calcium phosphate (CaP)-based substitute materials based on natural (allo- and xenografts) and synthetic origins (alloplastic materials) are applied for guiding the regeneration processes. The optimal bone substitute has to act as a substrate for bone ingrowth into a defect, while it should be resorbed even in the time frame needed for complete regeneration up to the condition of restitution ad integrum. In this context, the modes of action of CaP-based substitute materials have been frequently investigated and it has been shown that such materials strongly influence regenerative processes such as osteoblast growth or differentiation and also on osteoclastic resorption due to different physicochemical properties of the materials. However, the material characteristics needed for the required ratio between the formation of new bone tissue and material degradation has not been found until now. The addition of different substances such as collagen or growth factors and also of different cell types have already been tested but did not allow for sufficient or prompt application. Moreover, metals or metal ions are differently used as basis or as supplement for different materials in the field of bone regeneration. Moreover, it has already been shown that different metal ions are integral components of bone tissue playing functional roles in the physiological cellular environment as well as in the course of bone healing. The present review focuses on frequently used metals as integral parts of materials designated for bone regeneration with the aim to give an overview of currently existing knowledge about the effects of metals in the field of bone regeneration.
ARTICLE | doi:10.20944/preprints202311.1487.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: African Swine Fever; Histopathology; Immunohistochemistry; Tissue-specific prevalence
Online: 23 November 2023 (08:42:00 CET)
African Swine Fever (ASF) poses a significant threat to domestic pig populations worldwide. This study investigates the histopathological alterations in confirmed ASF-positive domestic pigs, focusing on over 100 cases from 2018 to 2021. Biological material from 118 pigs, confirmed ASF-positive via PCR examination, was histopathologically examined. Tissue samples from various organs were processed, embedded, and analyzed using hematoxylin and eosin staining. Immunohistochemistry (IHC) was employed to detect the major capsid protein (p72) of the ASF virus.Histological examination revealed characteristic ASF lesions, including severe hemorrhages, lymphoid depletion, and inflammatory infiltrates. Vascular anomalies leading to hemorrhagic events were widespread. Microthromboses were prevalent in lymph nodes and kidneys. IHC detected p72 in various organs, with tonsils consistently showing the highest viral presence.This comprehensive study underscores the pivotal role of lymph nodes, spleen, and kidneys in ASF pathogenesis, highlighting prominent vascular involvement and hemorrhagic manifestations. The study establishes the efficacy of IHC in detecting ASF virus, even in autolyzed tissue samples. Tonsils emerge as a consistent epicenter of viral presence, shedding light on the intricate pathogenesis of ASFV.
REVIEW | doi:10.20944/preprints202311.0178.v1
Subject: Engineering, Bioengineering Keywords: scar removal; nanotechnology; nanofibers; skin repair; tissue regeneration
Online: 3 November 2023 (06:25:31 CET)
Nanotechnology has become an increasingly promising medical field, particularly scar removal. Scar removal is a complex process involving regenerating damaged skin tissue, and nanotechnology presents unique solutions to this issue. One potential application of nanotechnology is using nanofibers as scaffolds to support the growth of new skin tissue. These fibres can also be loaded with drugs or growth factors to promote tissue regeneration and reduce scarring. Another potential application is nanocarriers for drug delivery to specific body areas, which can promote tissue regeneration and reduce scarring.Additionally, nanotechnology has been utilized to create new materials for skin regeneration, such as "nano skin" that mimics the structure of natural skin. Nanoprobes have also been developed for the detection of scar tissue and the monitoring of its progression. These potential nanotechnology applications offer exciting possibilities for the future of scar removal and skin repair. With further research and development, nanotechnology has the potential to revolutionize scar removal and provide more effective solutions for tissue regeneration.
ARTICLE | doi:10.20944/preprints202310.0542.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: demethyleneberberine; pharmacokinetics; tissue distribution; excretion; rats and mice
Online: 10 October 2023 (03:14:37 CEST)
Demethyleneberberine is an active component extracted from the Chinese herbal drug Cortex Phellodendri. It is also a metabolite of the berberine in animals and humans. However, the pharmacokinetics, tissue distribution and excretion of demethyleneberberine have not been reported. The present study aimed to investigate the pharmacokinetic parameters of demethyleneberberine by developing a method of high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The detection was performed by using positive ion electrospray ionization in multiple reaction monitoring mode. The MS/MS ion transitions were monitored at m/z 324.4→308.3 for demethyleneberberine and 465.5→350.3 for IS. After oral administration of demethyleneberberine in rats and mice, the pharmacokinetics, tissue distribution, and excretion of desmethylberberine in rats and mice were comparatively studied for the first time. The plasma concentration of desmethylberberine reached its peak within 5 min after oral administration in both rats and mice. The bioavailability of rats and mice was comparable, ranging from 4.47% to 5.94%, higher than that of berberine. The total excretion of desmethylberberine in urine, feces and bile is 7.28~9.77%. These findings provide valuable insights into the pharmacological and clinical research on desmethylberberine.
COMMUNICATION | doi:10.20944/preprints202309.2141.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: protoplast, Cannabis sativa, regeneration, AIP, phenylpropanoid, tissue culture
Online: 3 October 2023 (03:11:20 CEST)
De novo regeneration of Cannabis sativa L. (cannabis) using tissue culture techniques remains unreliable and infrequent. Conventional methods for the regeneration and transformation of cannabis have not achieved the reliability and replicability needed to be integrated into research and breeding programs. Protoplast systems are effective for gene expression studies, transformation and genome editing technologies, and opens the possibility of somatic hybridization to create interspecific hybrids. To date, leaf-derived protoplast have been isolated for transient gene expression studies, but attempts at protoplast-to-plant regeneration have not been reported. The present study aims to test the efficacy of using a callus culture system, as an abundant source for protoplast isolation and lays the groundwork for a protoplast-to-plant regeneration system. Using hypocotyl-derived callus cultures, which are known to have relatively greater regenerative potential, the efficacy of protoplast isolation and initial cell division were assessed. In this study, the effect of 2-aminoindane-2-phosphonic acid (AIP) in callus culture media and the effect of subculture frequency on protoplast yield were assessed. This study found that inclusion of AIP at 1 mM resulted in a 334% increase in protoplast yield compared with AIP-free medium, representing the first known use of AIP in cannabis tissue culture. Inclusion of AIP led to a 28% decrease in total soluble phenolics and 52% decrease in tissue browning compared to the control medium. Lastly, a two-phase culture system for protoplast regeneration was tested. At a concentration of 2.0×10^5 protoplasts per mL, division was observed, providing the first know report of cell division from cannabis protoplasts and setting the stage for future development of a protoplast-to-plant regeneration system.
ARTICLE | doi:10.20944/preprints202309.0983.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: cervical pain; musculoskeletal manipulation; stretching; soft tissue mobilisation
Online: 15 September 2023 (05:30:06 CEST)
Background: This study aimed to investigate the effect of fascial manipulation (FM) of the deep cervical fascia (DCF) and sequential yoga poses (SYP) on pain and function in individuals with mechanical neck pain (MNP). Method: Following the predefined criteria, ninety-nine individuals with MNP were recruited, randomised and assigned to either the intervention group (IG) (n=51) or the control group (CG) (n=48). Individuals in the IG received FM (4 sessions in 4 weeks) along with the home-based SYP (4 weeks). The CG participants received the usual care (cervical mobilization and thoracic manipulation (4 sessions in 4 weeks) along with unsupervised therapeutic exercises (4 weeks). The participants underwent baseline and weekly follow-up measurements of pain using a numerical pain rating scale (NPRS) and elbow extension range of motion (EEROM) during upper limb neurodynamic test 1 (ULNT1). The baseline and the 4th session follow-up measurements of the Patient-specific Functional Scale (PSFS) and Fear-avoidance Behavior Questionnaire (FABQ) were also taken. Results: A repeated-measures ANOVA was performed. The mean differences between the IG and CG on NPRS 3rd and 4th sessions are -1.009 (p< 0.05) and -1.701 (p< 0.001), respectively; on EEROM in the 4th session is 20.120 (p< 0.001); on FABQ during the follow-up is -5.036 (p<0.001), showing a statistically significant difference, whereas on PSFS during follow-up is 0.263 (p=0.566), suggesting no significant differences in PSFS. Conclusion: FM and SYP can aid in reducing pain and fear avoidance behavior as well as improving the function and extensibility of the upper quarter region.
ARTICLE | doi:10.20944/preprints202309.0678.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: bone regeneration; callus tissue; cissus quadrangularis; extracellular vesicles
Online: 12 September 2023 (05:44:18 CEST)
Exosomes are membrane-bound, biologically active nanovesicles of size 30-200 nm produced by many cell types, such as both mammalian and plant cells. They are wrapped in a phospholipid bilayer and play a significant role in intercellular communications. The ease in their isolation and the ability of plant-derived exosome-like nanovesicles (PDEVs) to efficiently deliver bioactive constituents into mammalian cells have made them popular in contemporary research. PDEVs share many characteristics with mammalian EVs (MEVs), including shape, size, surface charge, and consist of bioactive molecules like lipids, proteins, nucleic acids, and tiny metabolites. However, the chemical composition profile of PDEVs and their biogenesis mechanism differ significantly from those of MEVs. They have been widely explored as potential therapeutic agents and are considered as good alternatives to act as a carrier for drug delivery. The present work elucidates the isolation of exosome-like-nanovesicles (henceforth exosomes) from the culture supernatants of an in vitro cultured callus tissue derived from a bone healing plant known for its osteogenic activity, i.e., Cissus quadrangularis. The physical and biological properties of exosomes were successfully studied using different characterization techniques. To assess their therapeutic potential, we studied the internalisation of calcein-AM labeled exosomes by human derived mesenchymal stromal cells (hMSCs). Additionally, we evaluated the potential of exosomes in the migration of cells in a cell scratch assay with hMSCs and their effect on amelioration of oxidative stress was investigated on preosteoblast MC3T3-E1 cells that were pre-treated with these exosomes. Furthermore, we investigated their proliferation and differentiation to osteoblasts like cells with the help of resazurin assay and alkaline phosphatase assay (ALP). The obtained results provide a primary justification for the use of Cissus quadrangularis-derived exosomes as a nanocarrier for drug molecules for various therapeutic bone applications.
ARTICLE | doi:10.20944/preprints202307.1769.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: mesenchymal stem cells; proteomics; tissue engineering; regenerative medicine
Online: 26 July 2023 (07:06:41 CEST)
Mesenchymal stem cells (MSCs) are an attractive therapeutic tool for tissue engineering and regenerative medicine owing to their regenerative and trophic properties. The best-known and most widely used are bone marrow MSCs which are currently being harvested and developed from a wide range of adult and perinatal tissues. MSCs from different sources are believed to have different secretion potentials and production which may influence their therapeutic effects. To confirm it, we performed a quantitative proteomic analysis based on the TMT technique of MSCs from three different sources: Wharton’s jelly (WJ), dental pulp (DP) and bone marrow (BM). Our analysis focused on MSC biological properties of interest for tissue engineering. We identified a total of 611 differentially expressed human proteins. WJ-MSCs showed the greatest variation compared with the other sources. WJ produced more extracellular matrix (ECM) proteins and ECM-affiliated proteins and appeared more able to modulate the inflammatory and immune response. BM-MSCs displayed enhanced differentiation and paracrine communication capabilities. DP-MSC appeared to promote exosome production. The results obtained confirm the existence of differences between WJ, DP and BM-MSC and the need to select the MSC origin according to the therapeutic objective sought.
ARTICLE | doi:10.20944/preprints202307.1216.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Citrus rootstocks; tissue culture; biotechnology; NaCl; EDX; Stomata
Online: 19 July 2023 (02:54:35 CEST)
Salinity is the most significant abiotic stress affecting crop yield worldwide, breeders are Salinity is the most important abiotic stress limiting crop production throughout the world, and breeders are encouraged to test novel genotypes for their resistance to this selection agent. However, getting a sufficient number of plants for the evaluation can be a lengthy and time-consuming procedure that might be shortened by applying in vitro techniques. An experiment was conducted under controlled saline circumstances using a tissue culture technique to investigate the influence of salt on several physic-biochemical parameters. Micro-shoots of Volkamariana lemon, sour orange, trifoliate orange, and Cleopatra mandarin rootstocks were re-cultured on MS media supplemented with NaCl from 25, up to 150 mM. Following the experiments, all of the tested rootstocks' morphological and biochemical characteristics, stomata behavior, and element accumulation were measured. As a result, adding NaCl from 25 to 150 mM to MS media caused a reduction in all morphogenetic parameters such as shoot number, shoot length, leaves number, and survival percentage was measured compared with control. Photosynthesis pigment, RWC, K, and Ca ions were decreased by increasing NaCl from 100 to 150 mM. On the contrary, proline, Cl, and Na were increased. Cleopatra mandarin and Trifoliate orange are more tolerant to salt stress than Volkamariana lemon and sour orange citrus.
ARTICLE | doi:10.20944/preprints202306.1914.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: Additive Manufacturing; Tissue Engineering; DLP; Graphene Oxide; PLLA
Online: 27 June 2023 (13:03:50 CEST)
In this study, 3D printing of poly-l-lactic acid (PLLA) scaffolds reinforced with graphene oxide (GO) nanoparticles via Digital Light Processing (DLP) was investigated to mimic bone tissue. Stereolithography is one of the most accurate additive manufacturing method, but the dominant available materials used in this method are toxic. In this research, a biocompatible resin (PLLA) was synthetized and functionalized to serve the purpose. Due to the low mechanical properties of the printed product with the neat resin, graphene oxide nanoparticles in three levels (0.5, 1, and 1.5 Wt.%) were added with the aim of enhancing the mechanical properties. At first, the optimum post cure time of the neat resin was investigated. Consequently, all the parts were post-cured for three hours after printing. Due to the temperature-dependent structure of GO, all samples were placed in an oven at 85 ° C for different time periods of 0, 6, 12, and 18 hours to increase mechanical properties. The compression test of heat treated samples reveals that the compressive strength of the printed parts containing 0.5,1, and 1.5 % of GO increased by 151,162 ad 235%, respectively. Scaffolds with the designed pore sizes of 750 microns and a porosity of 40% were printed. Surface hydrophilicity test was performed for all samples showing that the hydrophilicity of the samples increased with increasing GO percentage. The degradation behavior of the samples was evaluated in a PBS environment, and it revealed that by increasing GO, the rate of component degradation increased, but the heat treatment had the opposite effect and decreased the degradation rate. Finally, besides improving biological properties, a significant increase in mechanical properties under compression can introduce the printed scaffolds as a suitable option for bone implants.
ARTICLE | doi:10.20944/preprints202306.1877.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: autophagy; acute laminitis; dairy cows; laminar tissue; oligofructose
Online: 27 June 2023 (09:53:38 CEST)
Laminitis is considered as an important underlying cause of lameness diseases, yet its specific pathogenesis remains unclear. Autophagy is an intracellular degradation mechanism that controls recycling of membrane-associated integrin and may aid in the progression of metabolic diseases. But the significance of autophagy for initiation and development of laminitis is unknown. The present study aimed to explore autophagy activity in the laminar tissue of dairy cows with oligofructose-induced laminitis. Twelve healthy non-pregnant Holstein cows were randomly divided to 2 groups of 6 cows each, entitled the control group and the oligofructose overload group (OF group), respectively. At 0 h, cows in OF group were gavaged with oligofructose (17 g/kg BW) dissolved in warm deionized water (20 mL/kg BW) through oral rumen tube, and dairy cows in control group were gavaged with the same volume of deionized water by the same method. At -72 h before perfusion as well as 0 h, 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 60 h, and 72 h after perfusion, clinical evaluations in both groups were monitored. After 72 h, laminar tissues of dairy cows in both groups were collected to examine genes and proteins. We found the significantly higher (P<0.05) levels of mRNA ATG5, ATG12, and Becilin1, but P62 and mTOR were extensively lower (P<0.01) in the laminar tissue of the OF group than the control group. Protein expression level of Becilin-1 was higher significantly (P<0.05), and the protein expression level of LC3II was lower significantly (P<0.05) in OF group than control group. However, the expression of P62 reduced (P>0.05) non-significantly in OF group than control group. The distribution of Beclin1 protein in laminar tissue increased (P<0.01) significantly, and distribution of P62 protein decreased (P<0.05) significantly in OF group than control group. In conclusion, laminar tissue damage occurred during the onset of laminitis, which promoted the occurrence of autophagy, and confirmed that autophagy was involved in the regulation and pathogenesis of laminitis in dairy cows.
CASE REPORT | doi:10.20944/preprints202306.1790.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: soft tissue injury; fibrin membranes; concentrated growth factors
Online: 26 June 2023 (10:32:40 CEST)
Accidental soft tissue injuries are a frequent injury. We report a case involving a 37-year-old man with a soft tissue wound failing conservative treatment. The use of applied fibrin membranes and concentrated growth factors yielded a resolution of the injury in 16 months without need of skin grafting.
REVIEW | doi:10.20944/preprints202306.1334.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: body composition; ergogenic aids; adipose tissue; strength training
Online: 19 June 2023 (09:06:57 CEST)
Adiposity is associated with adverse health conditions such as obesity, cardiovascular disease and type 2 diabetes. The combination of resistance exercise and creatine supplementation has been shown to decrease body fat % in adults ≥ 50 years of age. However, the effects in adults < 50 years of age is unknown. To address this limitation, we systematically reviewed the literature and performed several meta-analyses comparing studies that included resistance exercise and creatine supplementation to resistance exercise and placebo. Twelve studies were included involving 266 participants. Adults (< 50 years of age) that supplemented with creatine and performed resistance exercise experienced a significant reduction in body fat % (-1.19%, p=0.006) and a non-significant reduction in absolute fat mass (-0.09 kg, p=0.88). Collectively, the combination of resistance exercise and creatine supplementation produces a very small reduction in body fat % in adults < 50 years of age.
ARTICLE | doi:10.20944/preprints202305.1619.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Pigs; subcutaneous adipose tissue; transcriptomic; lipidomic; KEGG pathways
Online: 23 May 2023 (08:27:29 CEST)
Adipose tissue composition contributes greatly to the quality and nutritional value of meat. Transcriptomic and lipidomic techniques were used to investigate the molecular mechanism of fat deposition difference among Ningxiang, Berkshire and F1 pigs. Transcriptomic analysis identified 680, 592 and 380 differentially expressed genes (DEGs) by comparing the groups of Ningxiang pigs vs Berkshire pigs, Berkshire pigs vs F1 pigs, Ningxiang pigs vs F1 pigs. Lipidomic analysis screened 423, 252, and 50 significantly changed lipids (SCLs) by comparing the groups of Ningxiang pigs vs Berkshire pigs, Berkshire pigs vs F1 pigs, Ningxiang pigs vs F1 pigs. Lycine, serine and threonine metabolism pathway, fatty acid biosynthesis and metabolism related pathways were siginificant enriched in the groups of Berkshire pigs vs Ningxiang pigs and Berkshire pigs vs F1 pigs. The DEGs (PHGDH, LOC110256000) and the SCLs (Phosphatidylserines) may have a great impact on lycine, serine and threonine metabolism pathway. Moreover, the DEGs (FASN, ACACA, CBR4, SCD, ELOV6, HACD, CYP3A46, CYP2B22, GPX1, GPX3) and the SCLs (palmitoleic acid, linoleic acid, arachidonic acid, icosadienoic acid) play important role in fatty acid biosynthesis and metabolism. Thus, the fat deposition difference among Ningxiang, Berkshire and F1 pigs may be caused by the difference of the expression pattern of key genes in multiple enrichment KEGG pathways. The research presented multiple lipids that were potentially available biological indicator and screened key genes that were potentially gene targets for molecular design breeding. The research also explored the molecular mechanisms of fat deposition difference among Ningxiang, Berkshire and F1 pigs and provides insight into the selection of backfat thickness and fat composition of adipose tissue for future breeding strategies.
ARTICLE | doi:10.20944/preprints202305.1576.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: colorectal cancer; adipose tissue; miRNAs; serum biomarkers; obesity
Online: 23 May 2023 (05:03:00 CEST)
This work aims to investigate the expression levels of four preselected miRNAs previously linked to Cancer and/or Obesity, with the purpose of finding potential biomarkers in the clinical management of Colorectal Cancer (CRC) developed by obese and non-obese patients. We analyzed samples from a total of 65 subjects, 43 affected by CRC and 22 without cancer. Serum and both subcutaneous and omental adipose tissues (SAT and OAT) were analyzed, as well as tumor and non-tumor colorectal tissues in the case of the CRC patients. The relative expression (2-∆∆Ct) levels of 4 miRNAs (miR-181a-5p, miR-143-3p, miR-132-3p and miR-23a-3p) were measured by RT-qPCR. Serum, SAT and OAT expression levels of these miRNAs showed significant differences between subjects with and without CRC, especially in the group of overweight/obese subjects. In CRC serum levels of miR-181a-5p, miR-143-3p and miR-23a-3p correlated with their levels in both SAT and OAT. Moreover, in the case of miR-181a-5p, these correlations were significantly influenced by the body mass index (BMI). From these data, we can conclude that both adiposity and CRC induce changes in the expression of the miRNAs investigated, demonstrating the potential utility of this panel of miRNAs in the diagnosis and prognosis of CRC patients.
ARTICLE | doi:10.20944/preprints202305.1261.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: biocompatible materials; calcium phosphates; hydrated pastes; bone tissue
Online: 18 May 2023 (03:07:39 CEST)
The injectable hydrated calcium phosphate bone-like paste (hCPP) have been developed with suitable nanoscale characteristics and unindered injection through 23G standard needles. In vitro assays showed the cytocompatibility of hCPP with mesenchymal embryonic C3H10T1/2 cell cultures. The hCPPs were identified to be composed of aggregated nano-sized particles with sphere-like shapes with low crystallinity. The ability of serum proteins (FBS) to adsorb on hCPP particles was also studied. The hCPP demonstrated high protein adsorption capacity, thereby indicating its potential in various biomedical applications. The results of the in vivo assay upon subcutaneous injection in Wistar rats indicated the nontoxicity and biocompatibility of experimental hCPP, as well as the gradual resorption of hCPP, comparable to the period of bone regeneration. The data obtained are of great interest for the development of commercial highly effective osteoplastic materials for bone tissue regeneration and augmentation.