REVIEW | doi:10.20944/preprints201805.0396.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: diabetes; chronic wounds; smart wound dressing; biochemical sensor
Online: 28 May 2018 (10:22:39 CEST)
Given their severity and non-healing nature, diabetic chronic wounds are a significant concern to the 30.3 million Americans diagnosed with diabetes mellitus (2015). Peripheral arterial diseases, neuropathy, and infection contribute to the development of these wounds, which lead to an increased incidence of lower extremity amputations. Early recognition, debridement, offloading, and controlling infection are imperative for timely treatment. However, wound characterization and treatment are highly subjective and based largely on the experience of the treating clinician. Many wound dressings have been designed to address particular clinical presentations, but a prescriptive method is lacking for identifying the particular state of chronic, non-healing wounds. The authors suggest that recent developments in wound dressings and biosensing may allow for the quantitative, real-time representation of the wound environment, including exudate levels, pathogen concentrations, and tissue regeneration. Development of such sensing capability could enable more strategic, personalized care at the onset of ulceration and limit the infection leading to amputation. This review presents an overview of the pathophysiology of diabetic chronic wounds, a brief summary of biomaterial wound dressing treatment options, and biosensor development for biomarker sensing in the wound environment.
ARTICLE | doi:10.20944/preprints202211.0159.v1
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: care wound; wound diabetic; honey; staphylococcus aureus
Online: 9 November 2022 (01:07:32 CET)
Background : Diabetic wounds are very easy to experience complications in the form of infection due to bacterial invasion, and sugar conditions blood which tall encourage the growth of bacteria.Bacteria that can cause infection in diabetic wounds wrong one is staphylococci aureus . Wound diabetes can treated with honey. Honey contains antibacterial , antioxidant and hydrogen peroxide properties that help kill bacteria dangerous. Objective : The purpose of this study was to determine the effect of the wound dressing contains honey against bacterial colonization Staphylococcus aureus on wound diabetic . Methods : The research design used is pre-experimental with o ne-group pre-test and post-test design . Sampling method using consecutive sampling as many as 7 respondents. Results : Analysis data use test dependent t-test and obtained score p value 0.000 ( p value < = 0.05), so could concluded there is influence care wound use honey to colonization bacteria Staphylococcus aureus in wounds diabetic Diabetes Mellitus patients in the region work Public health center Banjarmasin . Conclusion : best Use honey as product care wound because nature the antibacterial which could prevent infection and speed up process healing wound .
REVIEW | doi:10.20944/preprints202103.0031.v1
Subject: Materials Science, Biomaterials Keywords: Dermal wound; Nanocuetical; Wound biochemistry; Wound healing mechanism
Online: 1 March 2021 (14:21:46 CET)
Dermal wound healing describes the progressive repair and recalcitrant mechanism of damaged skin and eventually reformatting and reshaping the skin. Many probiotics, nutraceuticals, metal nanoparticles have been associated with improved healing process of intra and inter tissue wounds. Despite the vast nature on material based wound healing mediators, the exact mechanism on material-cellular interaction is still point of repent issue particularly in diabetics and pathological condition. The use of bioengineered alternative agents will likely only continue to dominate the outpatient and perioperative management of chronic, recalcitrant wounds as new additional products continue to cut costs and improve wound healing process. This review article provides an update of the various remedies with confirmed wound healing activities by a diverse group of agents from previous experiments conducted by various researchers
ARTICLE | doi:10.20944/preprints202110.0417.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Diabetic wound; Achyranthes aspera; wound healing; burn wound; cotton; pellet granuloma; carrageenan-induced paw edema; Acute toxicity
Online: 27 October 2021 (14:16:41 CEST)
Introduction: Wound healing is a multifaceted biological process, and diabetic wounds add more complexity to it. In diabetic wounds, the combination of chloroform fractions of Achyranthes aspera L. (A.aspera) leaves with β-Glucans has not been investigated. The additive effect of these two (A.aspera + β-Glucans) would benefit the inflammatory phase of diabetic wounds, as improper treatment will lead to chronic injuries. Therefore, the goal of this research work was to assess the in-vivo wound healing and anti-inflammatory effects of a combination of chloroform fractions of A.aspera leaves and β-Glucans in a variety of wound models in STZ-induced diabetic rats. Methods: Preliminary phytochemical analyses of A.aspera were conducted to identify various phytoconstituents in the test extract. Acute and sub-acute dermal toxicity tests of A.aspera were carried out on mice and rats, respectively, to see whether there were any abnormalities. Excision and incision wound models, cotton pellet-induced granuloma models, rat paw edema and burn wounds were used to test wound healing and anti-inflammatory actions. To induce diabetes, streptozotocin (STZ) was administered intraperitoneally at a dosage of 65 mg/kg (i.p.). A.aspera (10% w/w) and β-Glucans (2% w/w) ointments were tested separately and in combination for wound healing activities. Silver sulfadiazine (1 % w/w) ointment was used to treat the positive control groups. Excision wound model rats that had been treated with basic ointment were used as negative controls, as were incision wound model rats that had not been treated. A.aspera (400 mg/kg, po) and β-Glucans (30 mg/kg, po) were tested separately and in combination for anti-inflammatory efficacy. Positive control groups were given indomethacin (10 mg/kg, po) for cotton pellet-induced granuloma and rat paw oedema models. Negative controls for both anti-inflammatory activity models were provided 2% Tween 80. The groups were made up of six rats, and the treatments were given topically and orally to assess wound healing and anti-inflammatory effects. The levels of hydroxyproline and hexosamine and the antioxidant enzymes (SOD and CAT) in the granulation tissue were measured in excision wound model. Healed excision wound skin was examined histopathologically. Results: The A.aspera and β-Glucans combination resulted in a significant percentage of wound contraction and a shorter epithelialization time (P<0.01). The combination was found to be the most effective, with the highest percentage of edema reduction (55 %; p<0.01). The combination also exhibited favourable hydroxylamine, hexosamine and anti-oxidant profiles supported by histopathology data. Conclusion: This research showed that the immunomodulatory effect of β-Glucans had significantly enhanced the wound healing, anti-inflammatory, and anti-oxidant potential of A.aspera in diabetic wounds.
REVIEW | doi:10.20944/preprints202109.0511.v1
Subject: Medicine & Pharmacology, Other Keywords: Wound; chronic wound; hypoxia; Lactate; Acidosis; Alkalosis; neoangiogenesis; ECM; Polylactide; polylactide membranes
Online: 30 September 2021 (12:18:52 CEST)
: Over time, we have come to recognize a very complex network of physiological changes enabling wound healing. An immunological process enables the body to distinguish damaged cells and begin a cleaning mechanism by separating damaged proteins and cells with matrix metallopro-teinases, a complement reaction, and free radicals. A wide variety of cell functions help to rebuild new tissue, dependent on energy provision and oxygen supply. Like in an optimized "biorector," disturbance can lead to prolonged healing. One of the earliest investigated local factors is the pH of wounds, studied in close relation to the local perfusion, oxygen tension, and lactate concentration. Granulation tissue with the wrong pH can hinder fibroblast and keratinocyte division and pro-liferation, as well as skin graft takes. Methods for influencing the pH have been tested, such as occlusion and acidification by the topical application of acidic media. In most trials, this has not changed the wound's pH to an acidic one, but it has reduced the strong alkalinity of deeper or chronic wound. Energy provision is essential for all repair processes. New insights into the metabolism of cells have changed the definition of lactate from a waste product to an indispensable energy provider in normoxic and hypoxic conditions. Neovascularization depends on oxygen provision and lactate, signaling hypoxic conditions even under normoxic conditions. An appropriate pH is necessary for successful skin grafting; hypoxia can change the pH of wounds. This review describes the close interconnections between the local lactate levels, metabolism, healing mechanisms, and pH. Furthermore, it analyzes and evaluates the different possible ways to support metabolism, such as lactate enhancement and pH adjustment. The aim of wound treatment must be the optimization of all these components. Therefore, the role of lactate and its influence on wound healing in acute and chronic wounds will be assessed.
ARTICLE | doi:10.20944/preprints202004.0117.v1
Subject: Medicine & Pharmacology, Other Keywords: acute compartment syndrome; negative pressure wound therapy; vacuum assisted wound closure; fasciotomy
Online: 8 April 2020 (04:50:32 CEST)
Background and Objectives: Acute compartment syndrome (ACS) is an emergency condition of the lower limb in which prophylactic fasciotomy is required to prevent complications. A negative pressure wound therapy (NPWT) used to the treatment of fasciotomy wounds provide beneficial clinical results. This study aimed to exchange the authors’ experience of using the NPWT installation system on the lower limb wounds after fasciotomy in ACS. Materials and Methods: This is a retrospective study enrolled consecutive patients with ACS, who underwent fasciotomy and was treated with the NPWT installation system at Department of Vascular Surgery, Provincial Hospital in Kielce from April 2016 to July 2017. Results: The study enrolled 15 patients with a diagnosis of ACS (87% men, mean age 65 years old). An open four-compartment fasciotomy (87%) or two-compartment fasciotomy (13%) was performed. The NPWT was applied on the first day after fasciotomy in 87% of patients. Therapy was initiated by the negative pressure of 125 mm Hg, which maintained at this level until the therapy was finalized. In 80% of patients, the vacuum-assisted wound closure (VAC) dressing changes were performed every 3 days. The first approximation of fasciotomy wounds margins occurred on the 4th day after surgery among 67% of individuals. The average time of using VAC on fasciotomy wounds was 9 days. The average time to definitive closure edges of fasciotomy wounds was 12 days. The average time of hospital stay was 17 days. Conclusions: Our experience indicates the legitimacy of using NPWT in wound treatment after fasciotomy in ACS. The NPWT enables faster primary closure of wounds, reduces edema, as well as decreases hospitalization time.
BRIEF REPORT | doi:10.20944/preprints202209.0409.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: chlorhexidine; bioactive liquid; oral wound healing; pain index score; early wound healing score
Online: 27 September 2022 (03:37:27 CEST)
After surgery, oral cavity healing occurs in a hostile environment and requires proper oral care and hygiene to accelerate recovery. The aim of the current study is to investigate and compare the bioreactivity characteristics of chlorhexidine based (CHX) mouth rinse and a novel bone bioactive liquid (BBL) mouth rinse on oral healing within seven days application post-surgery. A randomized, double blind clinical trial conducted in 81 patients. The mouth rinses were applied twice a day for a period of 7 days. The visual analog scale (VAS) protocol was applied to measure pain index. Early wound healing score (EHI) was determined in evaluate the oral cavity healing progress. No adverse effects were observed using the mouth washes, but CHX resulted in teeth staining. CHX and BBL were sufficient to reduce pain over a period of 7 days. However, the BBL group demonstrated a statistically significant reduction in VAS stating day 4. Relative to CHX group, the EHI scores were significantly higher in the BBL group, independent from the tooth location. No gender differences were observed in both VAS and EHI scores. Relative to the commercially available CHX, BBL mouth rinse reduced pain and accelerated oral cavity healing. Suggesting an improvements of oral cavity microenvironment at the wound site that mediates soft tissue regeneration.
REVIEW | doi:10.20944/preprints202205.0358.v1
Subject: Life Sciences, Biotechnology Keywords: Wound; Impregnated materials; Nanoparticles; Dermatology
Online: 26 May 2022 (08:51:48 CEST)
Wounds are structural and functional disruptions of the skin that occur because of an accident. Chronic wounds are caused by a breakdown in the finely coordinated cascade of events that occurs during wound healing. Wound healing is a long process that split into at least three continuous and overlapping processes: an inflammatory response, a proliferative phase that leads to tissue repair, and third one is tissue remodeling. Therefore, wound healing studies are extensively studied to develop techniques that can achieve maximum recovery with minimum scar. Several growth hormones and cytokines secreted at the wound site tightly regulate wound healing processes. The traditional approach for wound management has been represented by topical treatments. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being employed in dermatology due to their favorable effects on wound healing, as well as in treating and preventing bacterial infections. The development of wound dressings materials has now been used to overcome the issues of external environments. The impregnated nanomaterials have provided moist environment that removes the exudates and avoid maceration. This review highlights the mechanism and focus on the current advancement of various nanoparticles impregnation material for wound healing process that can protect wound from infection and maintain the optimum exchange of gases.
ARTICLE | doi:10.20944/preprints202011.0218.v1
Subject: Materials Science, Biomaterials Keywords: Ferroelectrics; Composite; Membranes; Wound healing
Online: 5 November 2020 (15:02:01 CET)
Herein, we report results of the study of the composite ferroelectric scaffolds based on vinylidene fluoride-tetrafluoroethylene copolymer (VDF-TeFE) and polyvinylpyrrolidone (PVP) produced by electrospinning and their application as a wound-healing material. The physicochemical properties of ferroelectric composite polymer scaffolds depending on the content of PVP (in the range from 0 to 50 wt %) including morphology, composition and crystalline structure were studied. The cytotoxicity of materials and the proliferative activity of cells during their cultivation on the surface of formed scaffolds are reported. It has been found that the optimal PVP content in the VDF-TeFE composite scaffolds is 15 wt%. On a model of a full-thickness contaminated wound in vivo, it was shown that piezoelectric scaffolds based on VDF-TeFE copolymer containing 15 wt% PVP provide better wound healing results in comparison with standard gauze dressings impregnated with a solution of an antibacterial agent.
ARTICLE | doi:10.20944/preprints201810.0667.v1
Online: 29 October 2018 (09:54:28 CET)
Visfatin, a member of the adipokine family, plays an important role in many metabolic and stress responses. The mechanisms underlying the direct therapeutic effects of visfatin on wound healing have not been reported yet. In this study, we examined the effects of visfatin on wound healing in vitro and in vivo. Visfatin enhanced the proliferation and migration of human dermal fibroblasts (HDFs) and keratinocytes, and significantly increased the expression of wound healing-related vascular endothelial growth factor (VEGF) in vitro and in vivo. Treatment of HDFs with visfatin induced activation of both extracellular signal-regulated kinases 1 and 2 (ERK1/2) and c-Jun N-terminal kinases 1 and 2 (JNK1/2) in a time-dependent manner. Inhibition of ERK1/2 and JNK1/2 led to a significant decrease in visfatin-induced proliferation and migration of HDFs. Importantly, blocking VEGF with its neutralizing antibodies suppressed the visfatin-induced proliferation and migration of HDFs and human keratinocytes, indicating that visfatin induces the proliferation and migration of HDFs and human keratinocytes via increased VEGF expression. Moreover, visfatin effectively improved wound repair in vivo, which was comparable to the wound healing activity of epidermal growth factor (EGF). Taken together, we demonstrate that visfatin promotes the proliferation and migration of HDFs and human keratinocytes by inducing VEGF expression and can be used as a potential novel therapeutic agent for wound healing.
ARTICLE | doi:10.20944/preprints201801.0063.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: spider venom; wound repair; loxoscelism.
Online: 8 January 2018 (10:49:36 CET)
We studied the efficacy of mesenchymal stem cells (MSC), either alone or associated with dapsone (DAP) in the treatment of dermonecrotic wounds caused by Loxosceles laeta spider venom. Twenty-five male adult rabbits were distributed into five groups, of which four groups received an intradermal injection of 20 μg of L. laeta venom and only one received ultrapure water (negative control). After 4 hours, each group that received venom, was treated with MSC, DAP, MSC + DAP and Phosphate-buffered saline – PBS (positive control). Photographic records were made for analysis of the wound area evolution by morphometry. Twelve days after treatment, the skin samples around the lesion were removed for subsequent histological analysis. Concerning the rate of wound contraction, we observed that DAP showed the best percentage of contraction at day 3. In the treatments using MSCs, a negative value of wound contraction was observed for the isolated MSCs, as well as a lower contraction value for the association of the MSC + DAP when compared to PBS group. Histopathological analysis showed diminished tissue lesion and less intense inflammation in MSCs and DAP groups. This could indicated potential use of stem cells in regenerative therapies after loxoscelic accidents.
REVIEW | doi:10.20944/preprints202104.0703.v1
Subject: Biology, Anatomy & Morphology Keywords: Cell mogration; Cutaneous wound healing; Wound healing assay; lab-on-a-chip; Skin; Microvasculature; Microfluidics
Online: 27 April 2021 (10:17:44 CEST)
Cutaneous wound healing is a complex multi-stage process involving direct and indirect cell communication events with the aim of efficiently restoring the barrier function of the skin. One key aspect in cutaneous wound healing is associated with cell movement and migration into the physically, chemically and biologically injured area resulting in wound closure. Understanding the conditions under which cell migration is impaired and elucidating the cellular and molecular mechanisms that improve healing dynamics is therefore crucial in devising novel therapeutic strategies to elevate patient suffering, reduce scaring and eliminate chronic wounds. Following the global trend towards automation, miniaturization and integration of cell-based assays into microphysiological systems, conventional wound healing assays such as the scratch assay or cell exclusion assay have recently been translated and improved using microfluidics and lab-on-a-chip technologies. These miniaturized cell analysis systems allow precise spatial and temporal control over a range of dynamic microenvironmental factors including shear stress, biochemical and oxygen gradients to create more reliable in vitro models that resemble the in vivo microenvironment of a wound more closely on a molecular, cellular, and tissue level. The current review provides (a) an overview on the main molecular and cellular processes that take place during wound healing, (b) a brief introduction into conventional in vitro wound healing assays, and (c) a perspective on future cutaneous and vascular wound healing research using microfluidic technology.
ARTICLE | doi:10.20944/preprints202011.0332.v1
Online: 12 November 2020 (09:13:12 CET)
In recent years, photobiomodulation (PBM) has been recognized as a physical therapy in wound management. Despite several published research papers, the mechanism underlying photobiomodulation is still not completely understood. The investigation about application of blue light to improve wound healing is a relatively new research area. Tests in selected patients evidenced a stimulation of the healing process in superficial and chronic wounds treated with a blue LED light emitting at 420 nm; a study in animal model pointed out a faster healing process in superficial wound, with an important role of fibroblasts and myofibroblasts. Here we present a study aiming at evidencing the effects of blue light on the proliferation and metabolism in fibroblasts and keratinocytes. Different light doses were used to treat the cells, evidencing inhibitory and stimulatory effects. Electrophysiology was used to investigate the effects on membrane currents, while Raman spectroscopy revealed the mitochondrial Cytochrome C (Cyt C) oxidase dependence on blue light irradiation. In conclusion, we observed that the blue LED light can be used to modulate the activity of human fibroblasts, and the effects in wound healing are particularly evident when studying the fibroblasts and keratinocytes co-cultures.
REVIEW | doi:10.20944/preprints202212.0048.v1
Subject: Materials Science, Biomaterials Keywords: poly(hexamethylene biguanide); polyhexamethylene biguanide; polyhexanide; PHMB; membrane; controlled drug release; wound dressing; antimicrobial; cytotoxicity; wound healing
Online: 2 December 2022 (10:31:38 CET)
The prevalence for chronic, non-healing skin wounds in the general population, most notably diabetic foot ulcers, venous leg ulcers and pressure ulcers, is approximately 2% and is expected to increase, driven mostly by an aging population and the steady rise in obesity and diabetes. Non-healing wounds often become infected, increasing the risk of life-threatening complications, which poses a significant socioeconomic burden. Aiming at an improved management of infected wounds, a variety of wound dressings incorporating antimicrobials (AMDs), namely polyhexanide (poly(hexamethylene biguanide); PHMB), have been introduced in the wound care market. However, many wound care professionals agree that none shows comprehensive and optimal antimicrobial activity. This manuscript summarizes and discusses studies on novel PHMB-releasing membranes (PRMs) for wound dressings, detailing their preparation, physical properties relevant in the context of AMDs, drug loading and release, antibacterial activity, biocompatibility, wound healing capacity, and clinical trials conducted. Some of these PRMs were able to improve wound healing in in vivo models, with no associated cytotoxicity, but significant differences in study design make it difficult to compare overall effi-cacies. It is hoped that this review, which includes, whenever available, international standards for testing AMDs, will provide a framework for future studies.their preparation, physical properties relevant in the context of AMDs, drug loading and release, antibacterial activity, biocompatibility, wound healing capacity, and clinical trials conducted. Some of these PRMs were able to improve wound healing in in vivo models, with no associated cytotoxicity, but significant differences in study design make it difficult to compare overall efficacies. It is hoped that this review, which includes, whenever available, international standards for testing AMDs, will provide a framework for future studies.
REVIEW | doi:10.20944/preprints202203.0293.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: extracellular matrix; biosensing; machine learning; wound healing
Online: 22 March 2022 (03:50:47 CET)
Impaired wound healing is a significant financial and medical burden. The synthesis and deposition of extracellular matrix (ECM) in a new wound is a dynamic process that is constantly changing and adapting to the biochemical and biomechanical signaling from the extracellular microenvironments of the wound. This drives either a regenerative or fibrotic and scar-forming healing outcome. Disruptions in ECM deposition, structure, and composition lead to impaired healing in diseased states, such as in diabetes. Valid measures of the principal determinants of successful ECM deposition include bacterial contamination, tissue perfusion, and mechanical injury and strain. These measures are used by wound-care providers to intervene upon the healing wound to steer healing toward a more functional phenotype with improved structural integrity and healing outcomes and to prevent adverse wound developments.In this review, we discuss bioengineering advances in non-invasive detection of biologic and physiologic factors of the healing wound, visualizing and modeling the ECM, and computational tools to efficiently evaluate the complex data acquired from the wounds to prognosticate healing outcomes and intervene effectively. We focus on bioelectronics and biologic interfaces of the sensors and actuators for real time biosensing and actuation. We also discuss high-resolution, advanced imaging techniques, which go beyond traditional confocal and fluorescence microscopy to visualize microscopic details of the composition of the matrix, linearity of collagen, and live tracking of components within the ECM. Computational modeling of the matrix, including partial differential equation datasets as well as machine learning models that can serve as powerful tools for physicians to guide their decision-making process are discussed.
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: wound infections; snakebites; Taiwan cobra; Naja atra
Online: 27 January 2021 (13:06:10 CET)
Taiwan cobra (Naja atra) bites account for approximately 20% of all venomous snakebites in Taiwan. In Taiwan, the rates of wound necrosis and secondary infection from Taiwan cobra bites are higher than those associated with other venomous snakebites. Clinical tools to evaluate the infection risk after Taiwan cobra bites are lacking. Therefore, in this study, we developed a useful clinical tool to evaluate the infection risk after Taiwan cobra bites. Moreover, we investigated wound infection bacteriology. We analyzed the data of patients bitten by N. atra who had undergone freeze-dried neurotoxic antivenin treatment in emergency rooms of the Chang Gung Memorial Hospital network, which comprises seven hospitals and the largest medical system in Taiwan, from January 2001 to May 2017. Because patients with wound necrosis required antibiotics for infection treatment, we included only patients with wound infection but without tissue necrosis in the development of our Cobra Bacteriology of Infections in Taiwanese snake Envenomation (Cobra BITE) score by using univariate and multiple logistic regression. In total, 8,295,497 emergency department visits occurred from January 2001 to May 2017, and 195 patients were diagnosed has having cobra bites. Among them, 23 and 30 patients had wound necrosis and wound infection, respectively. The wound infection rate was 27.2% (53/195). Regardless of whether the patients had necrosis, Enterococcus faecalis and Morganella morganii were the main bacteria identified in the culture report. Gentamicin, ceftriaxone, ciprofloxacin, and levofloxacin are the ideal first-line antibiotics for treating N. atra bite wounds in Taiwan. As per our Cobra BITE score, the three factors predicting secondary wound infection after cobra bites are hospital admission, a white blood cell count (in 103/µL) × by neutrophil–lymphocyte ratio value of ≥114.23, and the use of antivenin medication. The area under the receiver operating characteristic curve for the Cobra BITE score system was 0.88. The ideal sensitivity and specificity were 0.89 and 0.76, respectively, and the optimal cutoff point for Cobra BITE score was 7. The Hosmer–Lemeshow p value was 0.4. In conclusion, our Cobra BITE study established a new practical clinical tool for clinicians to evaluate infection risk after N. atra bites. This score system enables the assessment of wound infections after N. atra bites, and it could be modified and improved in future for other Naja spp. bites.
ARTICLE | doi:10.20944/preprints201905.0235.v1
Subject: Medicine & Pharmacology, Other Keywords: chronic wound; hospital cost; epidemiology; public health
Online: 20 May 2019 (09:53:44 CEST)
Background: Chronic lower limb ulcers (CLLU) have an important burden to the individual and the healthcare system. However, there is a lack of information about the cost of CLLU in Argentina.Objective: To determinate the number and cost of consultation and hospitalization associated to CLLU in a public hospital in Argentina. Methods: Retrospective observational study. Cost estimation were calculated based on days of stay, treatments and laboratory tests in a inpatient population and the number of consultations, treatments and laboratory tests, in a outpatient population. Results: In 2013 and 2014, the overall number of consultation with ICD-10 codes was 7,224 and the number of inpatient was 359. The mean age for male and female outpatient consultations was 59.53(±13.06) years and 59.04(±10.93), respectively. For CLLU male and female inpatient, the mean age was 63.9(±10.4) years and 54.5(±8.6) years, respectively. The length of stay was 22.88 days. There was a mean of 0.41 surgeries per patient where 25% were amputations. The mean annual cost in a single public hospital was US$4,053.65 per inpatient and US$3,589.24 per outpatient. Conclusion: Cost information allows new public health policies to reduce socioeconomic burden due to CLLU.
REVIEW | doi:10.20944/preprints202207.0040.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Kalanchoe; antibacterial; anti-inflammatory properties; wound healing; antioxidant
Online: 4 July 2022 (08:27:24 CEST)
The Kalanchoe genus is composed of more than 100 species that usually thrive in tropical environments, which have been used in folkloric medicine to treat various illnesses, including dermatological conditions. With this, the present study assesses the pharmacognostical and pharmacological properties of different species of the Kalanchoe genus as elements for a potential treatment for dermatological-related conditions, from findings of existing literature and studies. It was analyzed that the Kalanchoe pinnata plant, or one of the most common species of Kalanchoe, have been observed to have distinct morphological and microscopic characteristics. Further, it was discovered that different species of Kalanchoe have anti-inflammatory, antioxidant, antibacterial, and wound healing properties, which enable the plant to be used for dermatological products that are available to the market. With this, it is recommended that further studies be conducted in other understudied species of Kalanchoe regarding their pharmacological properties, as well as the use of other structures of the Kalanchoe plant for treatment of various dermatological conditions.
Subject: Biology, Plant Sciences Keywords: Regeneration; asexual propagation; multicellular organisms; wound repair; maturation
Online: 19 August 2021 (11:27:26 CEST)
Regeneration is usually regarded as a unique plant or some animal species process. In reality, regeneration is a ubiquitous process in all multicellular organisms. It ranges from response to wounding by healing the wounded tissue to whole body neoforming (remaking of the new body). In a larger context, regeneration is one facet of two reproduction schemes that dominate the evolution of life. Multicellular organisms can propagate their genes asexually or sexually. Here I present the view that the ability to regenerate tissue or whole-body regeneration is also determined by the sexual state of the multicellular organisms (from simple animals like hydra and planaria to plants and complex animals). The above idea is manifested here by showing evidence that many organisms, organs, or tissues show inhibited or diminished regeneration capacity when in reproductive status compared to the same organism organs or tissues in nonreproductive conditions or by exposure to sex hormones.
ARTICLE | doi:10.20944/preprints202101.0346.v1
Subject: Engineering, Other Keywords: Chronic wound classification; transfer learning; explainable artificial intelligence.
Online: 18 January 2021 (14:28:04 CET)
Artificial Intelligence (AI) has seen increased application and widespread adoption over the past decade despite, at times, offering a limited understanding of its inner working. AI algorithms are, in large part, built on weights, and these weights are calculated as a result of large matrix multiplications. Computationally intensive processes are typically harder to interpret. Explainable Artificial Intelligence (XAI) aims to solve this black box approach through the use of various techniques and tools. In this study, XAI techniques are applied to chronic wound classification. The proposed model classifies chronic wounds through the use of transfer learning and fully connected layers. Classified chronic wound images serve as input to the XAI model for an explanation. Interpretable results can help shed new perspectives to clinicians during the diagnostic phase. The proposed method successfully provides chronic wound classification and its associated explanation. This hybrid approach is shown to aid with the interpretation and understanding of AI decision-making processes.
ARTICLE | doi:10.20944/preprints202002.0430.v2
Subject: Life Sciences, Biotechnology Keywords: Co-culture; Reduced-serum; Wound bed; Fibroblasts; Keratinocytes
Online: 12 March 2020 (13:24:46 CET)
Contact-based co-culture of fibroblasts and keratinocytes is important to study the structure and functions of the wound bed. Co-culture of these two cell types in direct contact with each other has been challenging, requiring high serum concentrations (up to 10%), feeder systems and a range of supplemental factors. These approaches are not only technically demanding, but also present scientific, cost and ethical limitations associated with high-serum concentrations. We have developed two reduced-serum approaches (1-2%) to support contact-based co-culture of human dermal fibroblasts (HDFa) and human epidermal keratinocytes (HaCaT). The two approaches include (1) Specialized cell culture media for each cell type mixed in a 1:1 ratio (KGM+FGM), and (2) Minimal media supplemented with cell-specific growth factors (MEM+GF). Co-culture could be successfully achieved by co-seeding (two cell types were introduced simultaneously), or in a layered fashion (keratinocytes seeded on top of confluent fibroblasts). With wound scratch assays, the co-cultured platforms could demonstrate cell proliferation, migration and wound closure. The reduced-serum conditions developed are simple, easy to formulate and adopt, and based on commonly-available media components. These contact-based co-culture approaches can be leveraged for wound and skin studies, and tissue bioengineering applications, potentially reducing concerns with high-serum formulations.
REVIEW | doi:10.20944/preprints201906.0094.v1
Subject: Life Sciences, Microbiology Keywords: Bacteriophages, Septic wound infection, MDR, Biofilms, Phage Cocktails
Online: 11 June 2019 (10:08:07 CEST)
Lytic bacteriophages have the efficacy to act and eradicate pathogenic bacteria as an attractive tool in the near future. Bacteriophages specifically kill multidrug-resistant bacteria even which have the capacity to form biofilms. The present review mainly focused on the efficacy of bacteriophages and cocktails as therapeutic agents against predominate MDR-bacteria and their biofilms which are isolated from septic wound infections. The body of evidence includes data from studies investigating bacteriophages from sewage samples as novel antibacterial and antibiofilm agents against pathogenic bacteria. The goal of this review is to present an overview on predominant bacteria from septic wound infection, the biofilm-forming capacity of bacteria, lytic effect of bacteriophages and phage cocktails with an emphasis on the application of bacteriophages against septic wound causing bacteria.
ARTICLE | doi:10.20944/preprints201812.0192.v1
Subject: Life Sciences, Biotechnology Keywords: hepatic injury; sealants; metalloproteinases; inflammatory response; wound healing
Online: 17 December 2018 (10:52:27 CET)
This study examines the matrix metalloproteinase (MMP) activity in the healing of liver injuries treated with biological adhesives Tachosil® and GelitaSpon® and the elastic cyanoacrylate Adhflex®. Hepatic lesions were induced in male rats using a Stiefel biopsy punch. Healing was assessed 2, 6, and 18 days after injury by quantifying tissue levels of MMP1, 2, 8, 9, and 13. Histopathological repair was evaluated using hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining and immunohistochemical markers CD31 and CD68. The sealants contributed to complete healing. Histopathology and MMP findings indicate that Adhflex® has slower degradation and a strong inflammatory reaction at the onset of healing. Early on, all MMPs showed higher levels in Adhflex® and Tachosil®-treated animals, and MMP2 and MMP9 expressions were significantly higher in the Adhflex-treated group at 18 days post-injury (T3). The Adhflex® group had significantly higher MMP8 and MPP13 levels than other treated groups and showed a sustained overexpression of all MMPs, even in the latest healing stages. Notably, the overexpression did not negatively influence the histological healing process. All hepatic trauma injuries should be treated as emergencies, and any easy-to-use and rapid sealant like Adhflex® could be considered as an option for treating liver trauma.
ARTICLE | doi:10.20944/preprints201806.0334.v2
Subject: Life Sciences, Other Keywords: hepatic injury; sealants; metalloproteinases; inflammatory response; wound healing
Online: 27 June 2018 (10:43:43 CEST)
. Sealants and adhesives are used in the repair and preservation of damaged solid organs. This study examines the matrix metalloproteinases (MMP) activity in the healing of liver injuries treated with two biological adhesives (Tachosil® and GelitaSpon®) as well as that of a new elastic cyanoacrylate (Adhflex®). Methods. We induced in 90 male rats hepatic lesions using a Stiefel biopsy punch in the liver. Wound healing was assessed 2, 6, and 18 days after injury by quantifying MMP1, 2, 8, 9, and 13 tissue levels. The histopathological repair was evaluated by hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining and CD31, CD68 immunohistochemical marker. The three sealants used contributed to the complete healing of hepatic lesions. Both histopathology and MMP findings point to the fact that degradation with Adhflex® is slower and causes a strong inflammatory reaction at the onset of healing. Results. All the MMPs measured showed higher values early in the healing process in animals treated with Adhflex® and Tachosil, expression for MMP2 and MMP9 being significantly higher in the Adhflex-treated group. Animals treated with Tachosil had significant greater values of MMP8 and MPP13 than the Adhflex group. Animals treated with Adhflex® showed a sustained overexpression in all MMPs even at the latest wound healing stages. Conclusion. Notably, the overexpression of the MMPs did not negatively influence the histological healing process of liver injuries. Since all hepatic trauma injuries should be treated as emergencies, any easy-to-use and rapid sealant, like Adhflex®, could be considered an adequate treatment option.
REVIEW | doi:10.20944/preprints201805.0319.v1
Subject: Biology, Other Keywords: annexins; inflammation; wound healing; drug target; translational research
Online: 23 May 2018 (08:19:42 CEST)
The vertebrate annexin superfamily (AnxA) consists of 12 calcium (Ca2+) and phospholipid binding proteins which share a high structural homology. In keeping with this hallmark feature, annexins have been implicated in the Ca2+-controlled regulation of membrane events. In this review, we discuss several themes of potential therapeutic value, namely the regulation of the immune response and the control of tissue homeostasis, that repeatedly surface in the annexin action profile. Our aim is to identify and discuss those annexin properties which might be exploited from a translational science and specifically clinical point of view.
ARTICLE | doi:10.20944/preprints201804.0262.v1
Subject: Life Sciences, Biotechnology Keywords: hepatic injury; sealants; metalloproteinases; inflammatory response; wound healing
Online: 20 April 2018 (11:14:49 CEST)
Background. Adhesives and sealants can be used to repair and preserve solid damaged organs. This study explores the activity of different matrix metalloproteinases (MMP) during the healing of liver injuries treated with two biological adhesives (Tachosil and GelitaSpon) and a new synthetic elastic cyanoacrylate (Adhflex®). Methods. Liver traumatic injuries were experimentally induced in 90 male Wistar rats using a Stiefel biopsy punch in the liver. Wound healing was evaluated 2, 6, and 18 days after injury by determining MMP1, 2, 8, 9, and 13 expression. The histopathological repair was assessed by hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining. The three sealants used supported complete healing of the liver lesions. Both histopathology and MMP findings indicate that the degradation process of Adhflex® is slower and produces a strong initial inflammatory reaction. Results. All the MMPs measured disclosed higher values at early stage of the healing process in animals treated with Adhflex® and Tachosil, being the expression of for MMP2 and MMP9 significantly higher in the Adhflex-treated group. Animals treated with Tachosil had significant higher values of MMP8 and MPP13 than the Adhflex-treated group. Animals treated with Adhflex® showed a maintained overexpression in all the MMPs tested even at the latest wound healing stages. Conclusion. Notably, this MMPs overexpression did not influence negatively the histological healing process of the hepatic injuries. Given that all hepatic trauma injuries should be considered emergencies, any easy-to-use and rapid sealant, such as Adhflex®, could be considered as a suitable treatment option.
REVIEW | doi:10.20944/preprints202201.0035.v1
Subject: Materials Science, Biomaterials Keywords: Cellulose; Biomedical; Wound healing; Drug delivery; Antibacterials; Tissue engineering
Online: 5 January 2022 (11:00:57 CET)
There are various biomaterials in nature, but none fulfills all the requirements. Cellulose, eco-friendly material-based biopolymers, have been advanced biomedicine to satisfy most market demand and circumvent many ecological concerns. This review aims to present an overview of the state of the art in cellulose's knowledge and technical biomedical applications. It included an extensive bibliography of recent research findings for fundamental and applied investigations. The chemical structure of cellulose allows modifications and simple conjugation with several materials, including nanoparticles, without tedious efforts. Cellulose-based materials were used for biomedicine applications such as antibacterial agents, antifouling, wound healing, drug delivery, tissue engineering, and bone regeneration. They advanced the applications to be cheap, biocompatible, biodegradable, easy for shaping and processing into different forms, with suitable chemical, mechanical and physical properties.
ARTICLE | doi:10.20944/preprints202107.0597.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: 3D printing; microfabrication; microfluidic guillotine; single cell; wound healing
Online: 27 July 2021 (09:21:04 CEST)
Micro-blade design is an important factor in the cutting of single cells and other biological structures. This paper describes the fabrication process of three dimensional (3D) micro-blades for the cutting of single cells in a microfluidic “guillotine” intended for fundamental wound repair and regeneration studies. Our microfluidic guillotine consists of a fixed 3D micro-blade centered in a microchannel to bisect cells flowing through. We show that the Nanoscribe two-photon polymerization direct laser writing system is capable of fabricating complex 3D micro-blade geometries. However, structures made of the Nanoscribe IP-S resin have low adhesion to silicon, and they tend to peel off from the substrate after at most two times of replica molding in poly(dimethylsiloxane) (PDMS). Our work demonstrates that the use of a secondary mold replicates Nanoscribe printed features faithfully for at least 10 iterations. Finally, we show that complex micro-blade features can generate different degrees of cell wounding and cell survival rates compared with simple blades possessing a vertical cutting edge fabricated with conventional 2.5D photolithography. Our work lays the foundation for future applications in single cell analyses, wound repair and regeneration studies, as well as investigations of the physics of cutting and the interaction between the micro-blade and biological structures.
REVIEW | doi:10.20944/preprints202107.0361.v1
Subject: Medicine & Pharmacology, Allergology Keywords: wound healing; oxidative stress; antioxidant dressing; reactive oxygen species.
Online: 15 July 2021 (13:32:15 CEST)
(1) Background: Reactive oxygen species (ROS) play a crucial role in the preparation of the normal wound healing response. Therefore, a correct balance between low or high levels of ROS is essential. Antioxidant dressings that regulate this balance is a target for new therapies. The purpose of this review is to identify the compounds with antioxidant properties that have been tested for wound healing and to summarize the available evidence on their effects. (2) Methods: A literature search was conducted and included any study that evaluated the effects or mechanisms of antioxidants in the healing process (in vitro, animal models, or human studies). (3) Results: Seven compounds with antioxidant activity were identified (Curcumin, N-acetyl cysteine, Chitosan, Gallic Acid, Edaravone, Crocin, Safranal, and Quercetin) and 46 studies reporting the effects on the healing process of these antioxidants compounds were included. (4) Conclusions: These results highlight that numerous novel investigations are being conducted to develop more efficient systems for wound healing activity. The application of antioxidants is useful against oxidative damage and accelerates wound healing. Designing biomaterials that can scavenge excess reactive oxygen species requires new technologies and further research, especially human studies.
ARTICLE | doi:10.20944/preprints201806.0130.v1
Subject: Materials Science, Biomaterials Keywords: wound healing; catechol; conjugated; antioxidant; antiinflammatory; bioadhesion; UV shielding
Online: 8 June 2018 (12:28:07 CEST)
The effective treatment for chronic wounds constitute one of the most common worldwide health care problem due to the presence of high levels of proteases, free radicals and exudates in the wound, which constantly activate the inflammatory system avoiding the tissue regeneration. In this study, we describe a multifunctional bioactive and resorbable membrane with in-built antioxidant agent for the continuous quenching of free radicals as well as to control inflammatory response helping to promote the wound healing process. To reach that goal synthesized statistical copolymers of N-vinylcaprolactam (V) and 2-hydroxyethyl methacrylate (H) have been conjugated with catechol bearing hydrocaffeic acid (HCA) molecules. The natural polyphenol (catechol) is the key molecule responsible for the mechanism of adhesion of mussels, and provides the functionalized polymer conjugate a continuous antioxidant response, antiinflammatory effect, UV screen and bioadhesion in the moist environment of the human body, all of them key features in the wound healing process. Therefore, these novel mussel-inspired materials have an enormous potential of application and can act very positively, favoring and promoting the healing effect in chronic wounds.
ARTICLE | doi:10.20944/preprints202212.0004.v1
Subject: Medicine & Pharmacology, Other Keywords: SMI (silicone mammary implants); FBR (foreign body response); wound healing; wound infection; capsular fibrosis; implant encapsulation; early-stage fibrosis; surface adsorption; immunomics; biomarkers
Online: 1 December 2022 (02:02:11 CET)
The etiology of exaggerated fibrous capsule formation around silicone mammary implants (SMI) is multifactorial but primarily induced by immune mechanisms toward the foreign material silicone. The aim of this work was to enlighten the disease progression from implant insertion and immediate tissue damage response reflected in (a) the acute wound proteome, and (b) the adsorption of chronic inflammatory wound proteins at implant surfaces. An intra-individual absolute quantitation TMT-liquid chromatography-tandem mass spectrometry approach was applied to profile wound proteome formed around SMI the first five days post-implantation. Compared to plasma, the acute wound profile resembled a more complex composition comprising plasma-derived and locally differentially expressed proteins (DEPs). DEPs were subjected to functional enrichment analysis, which revealed the dysregulation of signaling pathways mainly involved in immediate inflammation response and ECM turnover. Moreover, we found time-course variations in protein enrichment immediately post-implantation and adsorbed to SMI surfaces after 6-8 months. Characterization of the expander-adhesive proteome by label-free approach uncovered a long-term adsorbed acute wound and the fibrosis-associated proteome. Our findings propose a wound biomarker panel for the early detection and diagnosis of excessive fibrosis that could potentially broaden insights into the characteristics of fibrotic implant encapsulation.
REVIEW | doi:10.20944/preprints202209.0354.v1
Subject: Medicine & Pharmacology, Other Keywords: Wound healing; metastasis; oxidative stress; macrophage; HIF; NF-kB; Nrf2
Online: 23 September 2022 (03:28:28 CEST)
Many signaling pathways, molecular and cellular actors which are critical for wound healing have been implicated in cancer metastasis. These two conditions are a complex succession of cellular biological events and accurate regulation of these events is essential. Apart from inflammation, macrophages-released ROS arise as major regulators of these processes. But, whatever the pathology concerned, oxidative stress is a complicated phenomenon to control and requires a finely tuned balance over the different stages and responding cells. This review provides an overview of the pivotal role of oxidative stress in both wound healing and metastasis, encompassing the contribution of macrophages. Indeed, macrophages are major ROS producers but also appear as their targets since ROS interfere with their differentiation and function. Elucidating ROS functions in wound healing and metastatic spread may allow the development of innovative therapeutic strategies involving redox modulators.
ARTICLE | doi:10.20944/preprints202202.0108.v1
Subject: Biology, Animal Sciences & Zoology Keywords: 3D printing technology; freshwater turtle; Ocadia Spp.; shell wound healing
Online: 8 February 2022 (12:22:31 CET)
Numerous cases and a shortage of resources usually limit wild animal rescue. New technology implemented might save these severely injured wild animals from the situation of euthanasia by easing the requirement of intensive medication. Three-dimensional (3D) technologies provide precise and accurate results that improve the quality of the medical application. These 3D tools have become relatively low-cost and accessible in the past years. In the medical field of exotic animal, turtle shell defect is highly challenging because of inevitable water immersion. This report is the first attempt to apply the combination of 3D scanning, computer-aid design (CAD), and 3D printing to make a protective device that frees the wound from exposure to water or infection sources. The presenting techniques successfully extricate a wild freshwater turtle from an extensive shell defect within a short period. Integration of multiple sciences to 3D technology can provide a facile model for veterinary medical applications.
ARTICLE | doi:10.20944/preprints202111.0134.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: HPV16; E7 variants; cervical cancer; transformation; wound healing; western blotting
Online: 8 November 2021 (12:28:30 CET)
The human papillomavirus (HPV) type 16 E7 oncogene is critical to carcinogenesis and highly conserved. Previous studies identified a preponderance of non-synonymous E7 variants amongst HPV16-positive cancer-free controls compared to those with cervical cancer. To investigate the function of E7 variants, we constructed full-length HPV16 E7 genes and tested variants at positions H9R, D21N, N29S, E33K, T56I, D62N, S63F, S63P, T64M, E80K, D81N, P92L, and P92S (found only in controls); D14E, N29H (CIN2), and P6L, H51N, R77S (CIN3). We determined the steady-state level of cytoplasmic and nuclear HPV16 E7 protein. All variants from the controls showed a reduced level of steady-state E7 protein, with 7/13 variants having deficient protein levels. In contrast, 2/3 variants from the CIN3 precancer group had near-normal E7 levels. We assayed the activity of representative variants in stably transfected NIH3T3 cells. The H9R, E33K, P92L, and P92S variants found in control subjects had lower transforming activity than D14E and N29H variants (CIN2); and the R77S (CIN3) had activity only slightly reduced from wildtype E7. In addition, R77S and WT E7 caused increased migration of NIH3T3 cells in a wound-healing assay as compared with H9R, E33K, P92L, and P92S (controls) and D14E (CIN2). These data provide evidence that the E7 variants found in HPV16-positive cancer-free women are partially defective for transformation and cell migration further demonstrating the importance of fully active E7 in clinical cancer development.
ARTICLE | doi:10.20944/preprints202105.0207.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Suture material; Third molar surgery; Surgical wound infection; Bacterial adhesion
Online: 10 May 2021 (15:08:53 CEST)
Background: Selection and application of suture materials, has gained more importance especially with the increasing number of patients seeking oral surgeries. Since lying in a bacterial-filled environment, sutures make the tissue prone to infection. Suture material plays an important role in the reduction of the risk of infection. This study aimed to assess the success rate of an antibacterial suture named Vicryl Plus in preventing bacterial growth in the surgical site of the mandibular third molar. Methods: 27 patients were included in this double-blinded randomized clinical trial study. Surgical Extraction of the mandibular wisdom tooth was done and the incision was managed by randomly using Vicryl Plus and Vicryl sutures. After 7 days, sutures were removed and assessed microbiologically. Predominant species of Streptococcus mutans and Lactobacillus were assessed as well as the total number of colonies on each suture. Results: There was a significant difference between two suture materials in colony number-length ratio of lactobacillus (p-value= 0.031) and total bacterial colonies (p-value=0.016); but not for S. mutans species (p-value=0.201). Conclusion: Antibacterial Vicryl suture can be a useful tool for the reduction in the rate of surgical site infection in high-risk cases and situations.
REVIEW | doi:10.20944/preprints202007.0519.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Burn wounds; ZnO NPs; Plant-based Green Synthesis; Wound healing
Online: 22 July 2020 (11:10:15 CEST)
In this changing world, we all are surrounded by the surmountable risk of getting injured. Amongst various risk factors, major burns are the most distressing and catastrophic. Burn wounds are not easy to heal via natural healing process and ultimately ended up with scar formation. If the degree of burn is high then the loss of tissue and its function is very common. To fasten-up the natural burn wound healing; zinc, an essential trace element is found to be very much effective. But due to its’ particle size limitation, less contact with wounded cells and tissues, and high inherent toxicity restrict its use. Needlessly, zinc is an element with dual action i.e. both antimicrobial and wound healing it is a prime choice to apply its aptitude in burn wound healing. To overcome the documented limitations zinc has converted to nanoparticle form. Zinc oxide nanoparticles, in particular, have attained ample of interest due to their unique properties and potential antimicrobial activity along with wound healing activity which makes it promising for the healing of topical burn wounds. Plant mediated green synthesis of nano-metal oxide particles is gaining a lot of significance due to its simplicity, eco-friendliness and extensive antimicrobial activity and recommended as an appealing substitute to not only physical methods but also chemical methods avoiding the use of the high rate of toxic chemicals and extreme surroundings. This study includes ZnO NPs role in burn wound healing with Phyto-mediated synthesis methods to provide evidence of their potential applications. Additionally, it provides an overview of traditional methods used for the synthesis of ZnO nanoparticles and characterization techniques to obtain information concerning the size, shape and optical properties along with toxicity and safety concern of ZnO NPs and its biomedical applications.
REVIEW | doi:10.20944/preprints202007.0284.v1
Subject: Medicine & Pharmacology, Other Keywords: seaweed; sulfated polysaccharides; alginates; fucoidans; carrageenans; ulvans; wound dressing; wounds
Online: 14 July 2020 (03:37:56 CEST)
Wound healing involves a complex cascade of cellular, molecular, and biochemical responses and signaling processes. It consists of successive interrelated phases, the duration of which depends on multifactorial processes. Wound treatment is a major healthcare issue that can be resolved by development of effective and affordable wound dressings based on natural materials and biologically active substances. Proper use of modern wound dressings can significantly accelerate wound healing with minimal cosmetic defects. The innovative biotechnologies for creating modern natural interactive dressings are based on sulfated polysaccharides from seaweeds with their unique structures and biological properties, the availability of their sources in the form of wild bushes, and in the form of aquaculture, as well as with a high potential for participation in process control wound healing. These natural biopolymers are a novel and promising biologically active source for designing wound dressings based on alginates, fucoidans, carrageenans, and ulvans, which serve as active and effective therapeutic tools. The aim of this review is to summarize available information about the modern wound dressing’s technologies based on seaweed-derived polysaccharides, including those successfully implemented in commercial products, with the emphasis on promising and innovative designs. The further prospect of using marine biopolymers is related to the need to analyze the results of numerous in vitro and in vivo experiments, summarize clinical trial data, develop a scientifically based approach and relevant practical recommendations for the treatment of wounds.
Subject: Life Sciences, Microbiology Keywords: honey; antimicrobials; methylglyoxal; hydrogen peroxide; bee-defensin 1; wound treatment
Online: 29 October 2019 (10:45:51 CET)
Honey is a complex sweet food stuff with well-established antimicrobial and antioxidant properties. It has been used for millennia in a variety of applications, but those most noteworthy include treatment of surface wounds, burns and inflammation. A variety of substances in honey have been suggested as the key component to its antimicrobial potential; polyphenolic compounds, hydrogen peroxide, methylglyoxal and bee-defensin 1. These components vary greatly across honey samples due to botanical origin, geographical location and the individual bee. The use of medical grade honey, Medihoney and Revamil, in the treatment of surface wounds and burns has been seen to improve the healing process, reduce healing time, reduce scarring and prevent microbial contamination. Therefore, medical grade honeys should be used for these treatments and reduce the demand for antibiotic usage. In this review, we aim to outline the constituents of honey and how they affect the antibiotic potential of honeys in a clinical setting.
REVIEW | doi:10.20944/preprints202211.0170.v1
Subject: Life Sciences, Biochemistry Keywords: wound healing; inflammation; microenvironment; stem cells; extracellular matrix; hypoxia; growth factors
Online: 9 November 2022 (03:41:12 CET)
Based on its large surface area and covering the whole human body, the skin body’s largest organ and its main function is protection. Injuries and wound healing involving the skin offer valuable lessons shared with and of relevance to other organ systems and the diseases that impact them. Arguably the most complex human body process, wound healing is a multifaceted process that involves multiple cells and the extracellular matrix (ECM), with each component playing a specific role in the different stages of the healing process. Importantly, studies indicate that cells with stem cell-like properties are present within many of the human tissues and play key roles in case of tissue and cellular injury. Cell-to-cell and cell-to-ECM interactions are salient in wound healing subsequent to an injury. Microenvironment related factors and the variations therein including hypoxia or the abundance of oxygen, the presence/absence of growth factors and cytokines add to the complexity of the wound healing process and impact cell function and result in compromised or enhanced wound healing. This expert review critically examines the advances in biochemical and analytical tools that are enable the analysis of numerous cells and molecules within the wound microenvironment, revealing great cellular heterogeneity as well as novel molecular targets of importance to enhance wound healing. In a broader angle, we emphasize the ways in which wound healing is significant in the search for perfect skin after injury and in many common complex human diseases including cancer. In all, wound healing is a centrepiece of integrative biology research and applications in medicine as well as dermatology as discussed in this review.
CASE REPORT | doi:10.20944/preprints202210.0422.v1
Subject: Life Sciences, Biotechnology Keywords: Breast Augmentation; Reduction Mammoplasty; non-healing surgical wound; Wharton's jelly allograft
Online: 27 October 2022 (07:56:25 CEST)
Nearly 15 million patients undergo cosmetic surgery in the United States each year, with breast augmentations such as implants, lifts, or reductions being some of the most common procedures. The most common complications of these procedures are scarring and infection at the incision site, which often necessitates expensive corrective surgery. After significant weight loss, the patient in this study underwent an elective lower body lift in conjunction with a breast reduction and nipple-areolar transplant. An autologous skin graft was used at the transplant donor site. The skin graft unfortunately necrosed, warranting the need for rapid wound closure to avoid further pain and infection. The patient was treated for eight weeks with conservative measures. After eight weeks of failed attempts to close her wound, she was referred for specialist care. Upon initial examination, the donor site wound measured 3.5 cm x 3.5 cm with no sign of epithelialization. The patient received a single dose of Wharton’s jelly flowable perinatal tissue allograft and five hyperbaric oxygen therapy treatments over seven weeks. Upon inspection at the final examination, the wound was closed entirely with 100% epithelialization overlying granulation tissue. This case study demonstrates a precedent for the application of Wharton’s jelly flowable allografts in complicated cosmetic post-surgical wounds. Future efforts will be directed at applying Wharton’s jelly allografts on a preventative basis. Preventative applications could be in stage 2 pressure sores or intra-operatively to decrease potential patient suffering, prevent emotional distress, and reduce unnecessary healthcare expenses.
ARTICLE | doi:10.20944/preprints202107.0540.v1
Subject: Biology, Anatomy & Morphology Keywords: polymeric spiral-wound membrane; microfiltration; transmembrane pressure; diafiltration; micellar casein concentrate
Online: 23 July 2021 (11:05:17 CEST)
Micellar Casein Concentrate (MCC) is manufactured from microfiltration (MF) of skim milk utilizing ceramic or polymeric membrane filtration. While ceramic filtration has higher efficiency, use of polymeric is cost effective and the process is familiar to several US dairy processors. The aim of the present study was to develop an optimized membrane filtration process to produce MCC using spiral wound polymeric membrane filtration (SW MF) system by systematic selection of transmembrane pressure (TMP) and level of diafiltration (DF). Using skim milk as feed material, preliminary lab-scale MF experiments were conducted using 0.5 µm polyvinylidene fluoride (PVDF) membrane. Three TMP (34.5, 62.1, and 103.4 kPa) and three levels of DF (70, 100, and 150%) along with a process without DF as control were used in the study. Effect of TMP and effectiveness of DF on flux rates, SP removal, casein to total protein (CN/TKN) ratio, casein to true protein (CN/TP) ratio, rejection of casein (rej CN) and SP (rej SP) were evaluated. At all TMP values used in the study, the overall flux (O Flux) increased with the level of DF. Highest O Flux of 30.77 liter per meter square per hour (LMH) was obtained with 34.5 kPa pressure and 150% DF. The impact of DF was more pronounced at lower pressures than at the higher pressures used in the study. With controlled DF, instantaneous flux was maintained within 80% of initial flux for the entire process run. For all the experiments, casein has a rejection of 0.97 to 1.0, while serum protein has the lowest rejection of 0.10 at 34.5 kPa pressure and 150% DF level. Use of 34.5 kPa and DF level of 150 % contributed to 81.45% SP removal, and casein to true protein ratio of 0.96. SP removal data from the lab-scale experiments were fitted into a mathematical model using DF and square of TMP as factors. The model predicts SP removal within 90-95% of actual SP removal got from the pilot plant experiments.
ARTICLE | doi:10.20944/preprints202106.0374.v1
Subject: Biology, Anatomy & Morphology Keywords: Mesenchymal Stem Cells 1; Cell Migration 2; Xenogeneic Wound Repair 3.
Online: 14 June 2021 (15:06:48 CEST)
Bone marrow derived adult human mesenchymal stem cells (hMSCs) possess therapeutic qualities that enable them to enhance wound repair. However, the mechanisms by which this occurs remains poorly understood. Basic mechanisms may include the directed migration of delivered cells to target sites and/or the production and release of soluble factors that act at a distance. Allogeneic and even xenogeneic cells may effectively participate in wound repair. Labeled hMSCs were delivered to full-thickness skin wounds that were created in immunologically competent mice. The delivery occurred on day 3 post-wounding using two different carriers; one which released cells and one which retained cells. The fates of the delivered cells were tracked for up to 25 days. During this period, released cells migrated as a tight cohort deep into the wound to reach the subdermal vascular plexus. Simultaneously, enhanced formation of granulation tissue was evident. This migration of hMSCs was not essential in that enhanced granulation tissue formation and wound contraction occurred when cells were retained in the carrier matrix. This provided further evidence for the release of therapeutic factors by hMSCs to sites of injury.
REVIEW | doi:10.20944/preprints202103.0229.v1
Subject: Life Sciences, Biochemistry Keywords: skin regeneration; wound healing; skin stem cells; skin vascularization; 3D printing.
Online: 8 March 2021 (15:26:04 CET)
In the past decades, regenerative medicine applied on skin lesions has been a field of constant improvement for both human and veterinary medicine. The process of healing cutaneous wound injuries implicates a well-organized cascade of molecular and biological processes. However, sometimes the normal process fails and can result in a chronic lesion. In addition, wounds are considered an increasing clinical impairment, due to the progressive ageing of the population, as well as the prevalence of concomitant diseases, such as diabetes and obesity, that represent risk aggravating factors for the development of chronic skin lesions. Stem cells regenerative potential has been recognized worldwide, including towards skin lesion repair, Tissue engineering techniques have long been successfully associated with stem cell therapies, namely the application of 3D bioprinted scaffolds. With this review we intend to explore several stem cell sources with promising aptitude towards skin regeneration, as well as different techniques used to deliver those cells and provide a supporting extracellular matrix environment, with effective outcomes. Furthermore, different studies are discussed, both in vitro and in vivo, towards their relevance in the skin regeneration field.
ARTICLE | doi:10.20944/preprints201911.0171.v1
Subject: Medicine & Pharmacology, Dermatology Keywords: ulmus parvifolia; wound healing; matrix metalloproteinase; transforming growth factor; skin rejuvernation
Online: 15 November 2019 (04:05:45 CET)
Ulmus species have been widely used in Korean folk medicine because of their anti-inflammatory and antimicrobial properties. We intended to investigate the wound healing effect of the powder of Ulmus parvifolia (UP) root bark in a mouse wound healing model. We also determined the mechanisms of effects of Ulmus parvifolia (UP) in skin and skin wound healing effect using keratinocyte model. in vivo experiments showed that the wound lesions in the mice decreased by U. parvifolia with 200 mesh size of root bark powder and significantly reduced by treatment with UP, compared with those treated with U. macrocarpa (UM). Results from in vitro experiments also revealed that UP extract promoted the migration of human skin keratinocytes. UP powder treatment upregulated the expression of the matrix metalloproteinase-2 and -9 protein and significantly increased transforming growth factor (TGF)-β levels. We confirmed that topical administration of the bark powder of exerted a significant effect on skin wound healing by upregulating the expression of MMP and transforming growth factor-β. TGF-β In, Our study suggests that U. parvifolia may be a potential candidate for skin wound healing including epidermal skin rejuvernation.
REVIEW | doi:10.20944/preprints201805.0378.v1
Subject: Biology, Other Keywords: annexins; inflammation; wound healing; host-pathogen interplay; drug target; translational research
Online: 27 May 2018 (11:32:34 CEST)
The vertebrate annexin superfamily (AnxA) consists of 12 members of a calcium (Ca2+) and phospholipid binding protein family which share a high structural homology. In keeping with this hallmark feature, annexins have been implicated in the Ca2+-controlled regulation of a broad range of membrane events. In this review, we identify and discuss several themes of annexin actions that hold a potential therapeutic value, namely the regulation of the immune response and the control of tissue homeostasis, and that repeatedly surface in the annexin activity profile. Our aim is to identify and discuss those annexin properties which might be exploited from a translational science and specifically clinical point of view.
ARTICLE | doi:10.20944/preprints202301.0150.v1
Subject: Life Sciences, Molecular Biology Keywords: oral; mucosa; mucins; tight junctions; wound-healing; E-liquids; cytotoxicity; viability; confluency
Online: 9 January 2023 (07:35:28 CET)
Background: Understanding in vitro expansion of OKF6/TERT-2 oral epithelial cells is important for studying molecular biology of disease and pathology affecting the oral cavity. The media used for any cell culture is paramount in terms of efficient output. Therefore, this study aims to compare two different media for OKF6/TERT-2 cultures: Keratinocyte Serum-Free Medium (KSFM) and a composite medium comprised of DMEM/F-12 mixed with KSFM (referred to as DFK). For application purposes, this investigation also compares the toxicological effects of flavored electronic cigarette liquids (E-liquids) on OKF6/TERT-2 cultures grown in both media. Methods: Cells were grown in KSFM and DFK media and cellular growth, morphology, gene expression of mucins and tight junctions, as well as wound-healing were determined. Additionally, cellular viability and cytotoxicity were indexed after E-liquid exposures. Results: While overall cellular morphologies remained unaltered, cells grown in DFK reached confluency faster. Except for claudin-1, there is no appreciable difference in expression of the other genes tested. Additionally, cultures in DFK appear more sensitive to E-liquids ± flavors. Conclusions: DFK is an alternative medium for cultivation of OKF6/TERT-2 cells to study molecular biology of disease and pathology, such as their responses to E-liquids ± flavors.
REVIEW | doi:10.20944/preprints202212.0108.v1
Subject: Chemistry, Medicinal Chemistry Keywords: Dendrimer; biomaterial; cell scaffold; hydrogel; wound repair; adhesion; differentiation; osseointegration.; hydroxyapatite; scaffold
Online: 7 December 2022 (01:57:27 CET)
The capability of radially polymerized bio-dendrimers and hyperbranched polymers for medical applications is well established. Among them, perhaps the most important are those that involve interactions with the regenerative mechanisms of cells. Dendritic polymers due to their distinctive architecture may play a multitude of roles such as protein biomimicry (collagen, elastin, hydroxy apatite production), gene and drug delivery (cell differentiation, antimicrobial protection), surface chemistry and charge modulation (adhesion to cells and tissues), polymer cross-linking (eye, skin and internal organ wound healing). The review highlights all the different categories of hard and soft tissues that may be remediated with their contribution. The reader will be also exposed to the incorporation methods to established biomaterials such as scaffolds, the functionalization strategies, and the synthetic paths for the assembly from biocompatible building blocks and natural metabolites.
ARTICLE | doi:10.20944/preprints202211.0119.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: biodegradable polymer nanosheets; wound healing; laser ablation in liquid; nanoparticles; ZnO; ZnCl2
Online: 7 November 2022 (11:20:14 CET)
So far, poly(L-lactic acid), PLLA, nanosheets proved to be promising for wound healing. Such biodegradable materials are easy-to-prepare, bio-friendly, cost-effective, simple to apply and were shown to protect burn wounds and facilitate their healing. At the same time, certain metal ions are known to be essential for wound healing, which is why this study was motivated by the idea of incorporating PLLA nanosheets with Zn2+ ion containing nanoparticles. Upon being applied on wound, such polymer nanosheets should release Zn2+ ions, which is expected to improve wound healing. The work thus focused on preparing PLLA nanosheets embedded with several kinds of Zn-containing nanoparticles, their characterization and ion-release behavior. ZnCl2 and ZnO nanoparticles were chosen as model particles with different solubility in water, both types showing similar ion release dynamics in liquid medium with pH around 7.4.
REVIEW | doi:10.20944/preprints202104.0652.v1
Subject: Materials Science, Biomaterials Keywords: Enzymatic reaction; crosslinking; Hydrogel; Biomedical application; Tissue engineering; Wound healing; Drug delivery
Online: 26 April 2021 (10:52:24 CEST)
Self-assembled structures mostly arises through enzyme-regulated phenomena in nature under persistent conditions. Enzymatic reactions are one of main biological processes in fabrication and construction of supramolecular hydrogel networks required for biomedical applications. The enzymatic processes provide a unique opportunity to integrate hydrogel formation. In most of cases, structure and substrates of hydrogels are adjusted by enzyme catalysis due to the chemo-, regio- and stereo-selectivity of enzymes. Hydrogels processed by using various enzyme schemes showed remarkable characteristics as dynamic frames for cells, bioactive molecules and drugs in biomedical applications. A novel class of enzyme-mediated crosslinking hydrogels mimics the extracellular matrices by displaying unique physicochemical properties and functionalities like water-retention capacity, drug loading ability, biodegradability, biocompatibility, biostability, bioactivity, optoelectronic properties, self-healing ability, shape memory ability. In recent years, many enzymatic systems investigated hydrogel cross-linking. Results of biocompatible hydrogel products show that these mechanisms of crosslinking can fulfill requirements for variety of biomedical applications including tissue engineering, wound healing and drug delivery.
REVIEW | doi:10.20944/preprints202102.0449.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: multifunctional; hydrogel nanocomposties; tissue engineering; drug delivery; wound healing; bioprinting; biowearable devices
Online: 22 February 2021 (08:48:20 CET)
Hydrogels are used for various biomedical applications due to their biocompatibility, capacity to mimic the extracellular matrix, and ability to encapsulate and deliver cells and therapeutics. However, traditional hydrogels have a few shortcomings, especially regarding their physical properties, thereby limiting their broad applicability. Recently, researchers have investigated the incorporation of nanoparticles (NPs) into hydrogels to improve and add to the physical and biochemical properties of hydrogels. This brief review focuses on papers that describe the use of nanoparticles to improve more than one property of hydrogels. Such multifunctional hydrogel nanocomposites have enhanced potential for various applications, including tissue engineering, drug delivery, wound healing, bioprinting and biowearable devices.
REVIEW | doi:10.20944/preprints202011.0053.v1
Subject: Life Sciences, Biochemistry Keywords: Mast cells; innate immunity; adaptive immunity; wound healing; Immunoglobin E; vaccine adjuvants
Online: 2 November 2020 (14:59:10 CET)
Mast cells are long-lived, granular, myeloid-derived leukocytes that have significant protective and repair functions in tissues. Mast cells sense disruptions in the local microenvironment and are first responders to physical, chemical and biological insults. When activated, mast cells release growth factors, proteases, chemotactic proteins and cytokines thereby mobilizing and amplifying the innate and adaptive immune system. Mast cells are therefore significant regulators of homeostatic functions and may be essential in microenvironmental changes during pathogen invasion and disease. During infection by helminths, bacteria and viruses, mast cells release antimicrobial factors to facilitate pathogen expulsion and eradication. Mast cell-derived proteases and growth factors protect tissues from insect/snake bites and exposure to ultraviolet radiation. Finally, mast cells release mediators that promote wound healing in the inflammatory, proliferative and remodeling stages. Since mast cells have such a powerful repertoire of functions, targeting mast cells may be an effective new strategy for immunotherapy of disease and design of novel vaccine adjuvants. In this review, we will examine how certain strategies that specifically target and activate mast cells can be used to treat and resolve infections, augment vaccines and heal wounds. Although these strategies may be protective in certain circumstances, mast cells activation may be deleterious if not carefully controlled and any therapeutic strategy using mast cell activators must be carefully explored.
Subject: Medicine & Pharmacology, Allergology Keywords: DPTM; Methicillin-resistant Staphylococcus aureus (MRSA); Antibacterial activity; Murine skin wound model; MIC
Online: 12 April 2021 (12:18:08 CEST)
Staphylococcus aureus (S. aureus) is a major human pathogen that requires new antibiotics with unique mechanism. A new pleuromutilin derivative, 14-O-[(4,6-Diaminopyrimidine-2-yl) thioacetyl] mutilin (DPTM), has been synthesized and proved as a potent antibacterial agent using in vitro and in vivo assays. In the present study, DPTM was further in vitro evaluated against Methicillin-resistant Staphylococcus aureus (MRSA) isolated from dairy farms and outperformed tiamulin fumarate, a pleuromutilin drug used for veterinary. Moreover, a murine skin wound model caused by MRSA infection was established and the healing effect of DPTM was investigated. The results showed that DPTM could promote the healing of MRSA skin infection, reduce the bacterial burden of infected skin MRSA and decrease the secretion of IL-6 and TNF-α inflammatory cytokines in plasma. These results provided the basis for further in-depth drug targeted studies of DPTM as a novel antibacterial agent.
REVIEW | doi:10.20944/preprints202108.0004.v1
Subject: Medicine & Pharmacology, Allergology Keywords: extracellular vesicles; EVs; exosomes; mesenchymal stem cell EVs; plant-derived EVs; wound healing; scaffolds
Online: 2 August 2021 (08:57:45 CEST)
Each year, millions of individuals suffer from a non-healing wound, abnormal scarring, or injuries accompanied by an infection. For these cases, scientists are searching for new therapeutic interventions, from which one of the most promising is the use of extracellular vesicles (EVs). Naturally, EV-based signalling takes part in all four wound healing phases: hemostasis, inflammation, proliferation and remodelling. Such an extensive involvement of EVs suggests exploiting their action to modulate the impaired healing phase. Furthermore, next to their natural wound healing capacity, EVs can be engineered for better defined pharmaceutical purposes, such as carrying specific cargo or targeting specific destinations by labelling them with certain surface proteins. This review aims to promote scientific awareness in basic and translational research of EVs by summarizing the current knowledge about their natural role in each stage of skin repair and the most recent findings in application areas, such as wound healing, skin regeneration and treatment of dermal diseases, including the stem cell-derived, plant-derived and engineered EVs.
ARTICLE | doi:10.20944/preprints202009.0703.v1
Subject: Chemistry, Analytical Chemistry Keywords: açaí; total polyphenol; total anthocyanin; antioxidant; elemental analysis; essential elements; biological activity; wound healing
Online: 29 September 2020 (09:14:48 CEST)
Chemical composition analysis of açaí extracts revealed higher levels of total polyphenol content in purple açaí samples for both commercial (4.3 – 44.7 gallic acid equivalents mg/g) and non-commercial samples (30.2 – 42.0 mg/g) compared to white (8.2 – 11.9 mg/g) and oil samples (0.8 – 4.6 mg/g). The major anthocyanin compounds found in purple açaí samples were cyanidin-3-glucoside and cyanidin-3-rutinoside with total concentrations in the range of 3.6 – 14.3 cyanidin-3-glucoside equivalents mg/g. The oligomeric proanthocyanidins were quantified in the range of 1.5 – 6.1 procyanidin B1 equivalents mg/g. Moreover, açaí presented significant levels of calcium, magnesium, manganese, iron, zinc and copper, essential minor and trace elements, in comparison with other berries. All of the açaí extracts at 50 μg/mL potently inhibited the release of reactive oxygen species in lipopolysaccharide-stimulated RAW 264.7 macrophage cells, but none inhibited the release of nitric oxide. Furthermore, all the açaí samples demonstrated potential as wound healing agents due to the high levels of migration activity in human fibroblast cells.
ARTICLE | doi:10.20944/preprints201801.0100.v1
Subject: Medicine & Pharmacology, Other Keywords: intra-abdominal pressure; abdominal compartment syndrome; pressure sensor; negative pressure wound therapy; open abdomen;
Online: 11 January 2018 (09:17:10 CET)
1) Introduction: Negative pressure wound therapy (NPWT) is a frequently applied open abdomen (OA) treatment. There are only a few experimental data supporting this method and describing the optimal settings and pressure distribution in the abdominal cavity during this procedure. The aim of our study was to evaluate pressure values at different points of the abdominal cavity during NPWT in experimental abdominal compartment syndrome (ACS) animal model. 2) Methods: In this study (permission Nr. 13/2014/UDCAR) 27 Hungahib pigs (15.4- 20.2 kg) were operated. ACS was generated by implanting a plastic bag in the abdomen through mini-laparotomy and filled with 2100- 3300 ml saline solution (37 C°) to an intraabdominal pressure (IAP) of 30 mmHg. After 3 hours, NPWT (Vivano Med ® Abdominal Kit, Paul Hartmann AG, Germany) or Bogota bag was applied. NPWT group was divided into -50, -100 and 150 mmHg suction group. Pressure distribution to the abdominal cavity was monitored at 6 different points of the abdomen via a multichannel pressure monitoring system. 3) Results: The absolute pressure levels were significantly higher above than below the layer. The values of the pressure were similar in the midline than laterally. Amongst the bowels, the pressure values changed periodically between 0 and -12 mmHg which might be caused by the peristaltic movements. 4) Conclusions: The porcine model of the present study seems to be well applicable for investigating ACS and NPWT. It was possible to provide valuable for clinicians. The pressure was well distributed by the protective layer to the lateral parts of the abdomen and this phenomenon did not change considerably during the therapy.
REVIEW | doi:10.20944/preprints201712.0186.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: cardiovascular diseases; atherosclerosis; oxidative stress; angiogenesis and arteriogenesis; endothelial dysfunction; growth hormone; IGF-I; wound healing
Online: 26 December 2017 (10:30:09 CET)
This review describes the positive effects of growth hormone on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on the vascular endothelium improving its dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease inducing the generation of new collateral vessels able to bypass a major artery occlusion. We include some preliminary data from a trial in which GH or placebo is given to elder people suffering from critical limb ischemia, showing the effects of the hormone on plasma markers of inflammation, and stating that the administration of GH in short periods of time is safe and effective even in diabetic patients. We also analyze how Klotho may have strong relationships with GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH to repair the damaged tissue. Lastly, we show how GH induces wound healing by increasing the blood flow to the ischemic tissue. In summary, we postulate that short-time GH administration is useful for treating cardiovascular diseases.
ARTICLE | doi:10.20944/preprints202209.0026.v1
Subject: Chemistry, Medicinal Chemistry Keywords: Bacopa procumbens HPLC characterization; effect of polyphenolic compounds; in vitro and in vivo skin wound; collagen organization
Online: 1 September 2022 (15:44:09 CEST)
Wounds represents a medical problem that contribute importantly to patient morbidity and to the healthcare costs in several pathologies. In Hidalgo, Mexico, Bacopa procumbens plant has been traditionally used for wound healing care for several generations; in vitro and in vivo experiments were design to evaluate the effects of bioactive compounds obtained from B. procumbens aquoethanolic extract and to determine the key pathways involved in wound regeneration. Bioactive compounds were characterized by HPLC- QTOF-MS and proliferation, migration, adhesion, and differentiation studies were done on NIH/3T3 fibroblasts. Polyphenolic compounds from Bacopa procumbens (PB) regulated proliferation and cell adhesion; enhanced migration reducing the artificial scratch area; and modulated cell differentiation. PB compounds were included in a hydrogel for topical administration on rat excision wound model. Histological, histochemical and mechanical analysis showed that PB treatment accelerates wound closure in at least 48 h; reduce inflammation, increasing cell proliferation and deposition and organization of collagen in earlier times. These changes resulted in the formation of a scar with better tensile properties. Immunohistochemistry and RT-PCR molecular analyses demonstrated that treatment induces: i) overexpression of transforming growth factor beta (TGF-β); and ii) the phosphorylation of Smad 2/3 and ERK1/2, suggesting the central role of some PB to enhance wound healing, modulating TGF-β activation.
REVIEW | doi:10.20944/preprints202012.0029.v1
Subject: Materials Science, Nanotechnology Keywords: drug delivery; immune response; inflammation; critical solution temperature; scaffolds; smart polymers; tissue engineering; thermo-responsive; wound healing.
Online: 1 December 2020 (13:55:35 CET)
innate and adaptive immune responses lead to wound healing by regulating a complex series of events promoting cellular cross-talk. An inflammatory response is presented with its characteristic clinical symptoms: heat, pain, redness, and swelling. Some smart thermo-responsive polymers like chitosan can be used to create biocompatible and biodegradable scaffolds with 3D architectures similar to human structures, allowing their efficient and safe use as tissue engineering and drug delivery systems in chronic wounds. Locally heated tumors above polymer lower critical solution temperature can induce its conversion into a hydrophobic form, enhancing drug release until the thermal stimulus is gone, where a lower release is due to the swelling of the material. This paper integrates the relevant reported contributions of bioengineered scaffolds for thermo-responsive drug delivery in wound healing. Therefore, we present a comprehensive review that aims to demonstrate the capacity of these systems to provide spatially and temporally controlled release strategies for one or more drugs used in wound healing. In this sense, the novel manufacturing techniques of 3D-printing and electrospinning are explored for the tuning of their physicochemical properties to adjust therapies according to the patient’s convenience, as well as reduce drug toxicity and side effects.
REVIEW | doi:10.20944/preprints202012.0578.v2
Subject: Life Sciences, Biochemistry Keywords: Unfolded protein response; Endoplasmic reticulum stress; Glucose-regulated protein 78 kD; Inflammatory Bowel Diseases; Crohn’s disease; Fibrosis; Wound healing
Online: 12 January 2021 (17:03:10 CET)
Endoplasmic reticulum (ER) stress triggers a series of signaling and transcriptional events termed the unfolded protein response (UPR). Severe ER stress is associated with the development of fibrosis in different organs including lung, liver, kidney, heart, and intestine. ER stress is an essential response of epithelial and immune cells in the pathogenesis of inflammatory bowel disease (IBD) including Crohn’s disease. Intestinal epithelial cells are susceptible to ER stress-mediated damage due to secretion of a large amount of proteins that are involved in mucosal defense. In other cells, ER stress is linked to myofibroblast activation, extracellular matrix production, macrophage polarization, and immune cell differentiation. This review focuses on the role of UPR in the pathogenesis in IBD from an immunologic perspective. The roles of macrophage and mesenchymal cells in the UPR from in vitro and in vivo animal models are discussed. The links between ER stress and other signaling pathways such as senescence and autophagy are introduced. Recent advances in the understanding of the epigenetic regulation of UPR signaling are also updated here. The future directions of development of the UPR research and therapeutic strategies to manipulate ER stress levels are also reviewed.
REVIEW | doi:10.20944/preprints201812.0170.v1
Subject: Life Sciences, 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.
ARTICLE | doi:10.20944/preprints202107.0142.v1
Subject: Biology, Anatomy & Morphology Keywords: Arabidopsis thaliana; indole-3-acetic acid; jasmonic acid; plant hormone crosstalk; transcriptional regulation; wound response; biotic stress; growth-defense trade-off
Online: 6 July 2021 (12:20:15 CEST)
The indole-3-pyruvic acid pathway is the major route for auxin biosynthesis in higher plants. Tryptophan aminotransferases (TAA1/TAR) and members of the YUCCA family of flavin-containing monooxygenases catalyze the conversion of L-tryptophan via indole-3-pyruvic acid into indole-3-acetic acid (IAA). It has been described that locally produced jasmonic acid (JA) in response to mechanical wounding, triggers de novo-formation of IAA through the induction of two YUCCA genes, YUC8 and YUC9. Here, we report the direct involvement of a small number of basic helix-loop-helix transcription factors of the MYC family in this process. We show that the JA-mediated regulation of YUC8 and YUC9 gene expression depends on the abundance of MYC2, MYC3, and MYC4. In support of this observation, seedlings of myc knockout mutants displayed a strongly reduced response to JA-mediated IAA formation. In addition, transactivation assays provided experimental evidence for the binding of the MYC transcription factors to a particular tandem G-box motif abundant in the promoter regions of YUC8 and YUC9, but not in those of the other YUCCA genes. Moreover, we clearly demonstrate that YUC8ox and YUC9ox overexpressing plants show less damage after spider mite infestation, thereby underlining a role of auxin in plant responses toward biotic stress cues.
ARTICLE | doi:10.20944/preprints202010.0392.v1
Subject: Medicine & Pharmacology, Allergology Keywords: antimicrobial stewardship; detection of bacteria in chronic wounds, chronic wounds, clinical decision support; diagnostic pathway; joint commission; fluorescence imaging; wound clinic
Online: 19 October 2020 (15:35:25 CEST)
Background: In 2014 the World Health Organization (WHO) warned of an emerging world-wide crisis of antibiotic resistant microorganisms. In response, government and professional organizations recommended that health care systems adopt antimicrobial stewardship programs (ASPs). In the United States, the Centers for Medicare Services (CMS) mandated antimicrobial stewardship in the hospital inpatient setting. Effective January 1, 2020, the Joint Commission required ambulatory centers that prescribe antibiotics, such as wound centers, to institute an ASP. Chronic wounds often remain open for months, during which time patients may receive multiple courses of antibiotics and numerous antimicrobial topical treatments. The wound clinician plays an integral role in reducing antimicrobial resistance in the outpatient setting: antibiotics prescribed for skin and soft tissue infections are among the most common in an outpatient setting. One of the most challenging aspects of antimicrobial stewardship in treating chronic wounds is the inaccuracy of bacterial and infection diagnosis. Methods: Joint Commission lists five elements of performance (EP): (1) Identifying an antimicrobial stewardship leader, (2) establishing an annual antimicrobial stewardship goal, (3) implementing evidence-based practice guidelines related to the antimicrobial stewardship goal, (4) providing clinical staff with educational resources related to the antimicrobial stewardship goal, and (5) collecting, analyzing, and reporting data related to the antimicrobial stewardship goal. This article focuses on choosing and implementing an evidence-based ASP goal for 2020. Discussion: Clinical trials have demonstrated the ability of fluorescence imaging (MLiX) to detect clinically significant levels of bacteria in chronic wounds. Combined with clinical examination of signs and symptoms of infection, the MLiX procedure improves the clinician’s ability to diagnose infection and can guide antimicrobial use. In order to satisfy the elements of performance, the MLiX procedure was incorporated into the annual ASP goal for several wound care centers. Clinicians were educated on the fluorescence imaging device and guidelines were instituted. Collection of antimicrobial utilization data is underway.
REVIEW | doi:10.20944/preprints201805.0413.v1
Subject: Life Sciences, Other Keywords: silver nanoparticles; nanosilver; endocytosis; oxidative stress; reactive oxygen species; inflammation; wound healing; hypoxia; mitochondria; endoplasmic reticulum stress; unfolded protein response; autophagy; apoptosis; angiogenesis; epigenetics; genotoxicity; cancer; anti-cancer
Online: 28 May 2018 (15:51:12 CEST)
Nanosilver plays an important role in nanoscience and nanotechnology, and is becoming increasingly used for applications in nanomedicine. Nanosilver ranges in size from one to one hundred nanometers. Smaller particles more readily enter cells and interact with the cellular components. The exposure dose, particle size, coating, and aggregation state of the nanosilver, as well as the cell type or organism that it is tested on, all have a large determining factor on the effect and potential toxicity of nanosilver. A high exposure dose to nanosilver alters the cellular stress responses and initiates cascades of signaling that can eventually trigger organelle autophagy and apoptosis. This review summarizes the current knowledge of the effects of nanosilver on cellular metabolic function and response to stress. Both the causative effects of nanosilver on oxidative stress, endoplasmic reticulum stress, and hypoxic stress, as well as the effects of nanosilver on the responses to such stresses, are outlined. The interactions and effects of nanosilver on cellular uptake, oxidative stress (reactive oxygen species), inflammation, hypoxic response, mitochondrial function, endoplasmic reticulum function and the unfolded protein response, autophagy and apoptosis, angiogenesis, epigenetics, genotoxicity, and cancer development and tumorigenesis, as well as other pathway alterations are examined in this review.
REVIEW | doi:10.20944/preprints202101.0304.v1
Subject: Life Sciences, Biochemistry Keywords: Vascular Endothelial Growth Factors (VEGFs); VEGF-A; PlGF; VEGF-B; VEGF-C; VEGF-D; angiogenesis; lymphangiogenesis; CCBE1; proteases; ADAMTS3; plasmin; cathepsin D; KLK3; prostate-specific antigen (PSA); thrombin; wound healing; metastasis; proteolytic activation; vascular biology
Online: 18 January 2021 (09:05:58 CET)
Specific proteolytic cleavages turn on, modify, or turn off the activity of vascular endothelial growth factors (VEGFs). Proteolysis is most prominent among the lymphangiogenic VEGF-C and VEGF-D, which are synthesized as precursors that need to undergo enzymatic removal of their C- and N-terminal propeptides before they can activate their receptors. The activating cleavage of VEGF-C is mediated by at least five different proteases: plasmin, ADAMTS3, prostate-specific antigen, cathepsin D, and thrombin. All of these proteases except for ADAMTS3 can also activate VEGF-D. Processing by different proteases results in distinct forms of the "mature" growth factors, which differ in affinity and receptor activation potential. The “default” VEGF-C-activating enzyme ADAMTS3 does not activate VEGF-D and therefore, VEGF-C and VEGF-D do function in different contexts. VEGF-C itself is also regulated in different contexts by different proteases. During embryonic development, ADAMTS3 activates VEGF-C. In contrast, thrombin and plasmin likely activate VEGF-C/-D during tissue injury-induced lymphangiogenesis, and PSA and cathepsin D perhaps during tumor-associated pathological lymphangiogenesis. Additionally, cathepsin D from saliva might activate latent VEGF-C/-D upon wound licking, thereby accelerating healing. Similar to tyrosine kinase receptors and VEGFs themselves, these activating proteases could be targeted to modulate angiogenesis and lymphangiogenesis in relevant diseases.