ARTICLE | doi:10.20944/preprints201806.0047.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: biodegradable nanofibers; PLGA; masquelet technique
Online: 5 June 2018 (05:35:14 CEST)
Masquelet induced-membrane technique for the treatment of segmental bone defects includes a two-stage surgical procedure, and polymethylmethacrylate (PMMA) plays a major role in the treatment. However, the PMMA spacer must be surgically removed. Here, we investigated the potential of poly (lactic-co-glycolic acid) (PLGA) nanofibers, a biodegradable material to replace PMMA spacer, allowing the bioactive membrane to be induced, and the spacer to degrade without the additional surgery on a rabbit femoral segmental bone defect model. PLGA nanofibers were shown to degrade completely six weeks after implantation in the investigated animals, and a thick membrane was found to circumferentially fold around the segmental bone defects. Results from image studies demonstrated that, in the group without bone graft, all studied femurs exhibited either nonunion or considerable malunion. In contrast, the femurs in the bone graft group had a high union rate without considerable deformities. Histological examinations suggested that the membranous tissue in this group was rich in small blood vessels and the expression of BMP2 and VEGF increased. Our results demonstrate that the biodegradable PLGA nanofibers may be useful for replacing the PMMA spacer as the bioactive-membrane inducer, facilitating the process of healing and removing the need for repeated surgeries.
ARTICLE | doi:10.20944/preprints201910.0027.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: PLGA; drug delivery systems; microfluidics; nanoparticles; microparticles
Online: 2 October 2019 (09:21:39 CEST)
Polymeric particles made up of biodegradable and biocompatible polymers such as poly(lactic-co-glycolic acid) (PLGA) are promising tools for several biomedical applications including drug delivery. Particular emphasis is placed on the size and surface functionality of these systems as they are regarded as the main protagonists in dictating the particle behavior in vitro and in vivo. Current methods of manufacturing polymeric drug carriers offer a wide range of achievable particle sizes, however, they are unlikely to accurately control the size while maintaining the same production method and particle uniformity, as well as final production yield. Microfluidics technology has emerged as an efficient tool to manufacture particles in a highly controllable manner. Here, we report on tuning the size of PLGA particles at diameters ranging from sub-micron to microns using a single microfluidics device, and demonstrate how particle size influences the release characteristics, cellular uptake and in vivo clearance of these particles. Highly controlled production of PLGA particles with ~100 nm, ~200 nm and >1000 nm diameter is achieved through modification of flow and formulation parameters. Efficiency of particle uptake by dendritic cells and myeloid-derived suppressor cells isolated from mice is strongly correlated with particle size and is most efficient for ~100 nm particles. Particles systemically administered to mice mainly accumulate in liver and ~100 nm particles are cleared slower. Our study shows the direct relation between the particle size varied through microfluidics and the pharmacokinetics behavior of particles, which provides a further step towards the establishment of a customizable production process to generate tailor-made nanomedicines.
CASE REPORT | doi:10.20944/preprints202311.0102.v2
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: Osteochondral fracture; Absorbable; PLGA; Osteosynthesis; Articular fracture; OCF; Articular congruency
Online: 6 November 2023 (07:40:58 CET)
The incidence of articular injury, particularly osteochondral fractures (OCF), has seen a notable increase in recent years. Regardless of their location, fragments might be overlooked by plain radiographs which might lead to osteoarthritis in the long run. Diagnostic imaging has a pivotal role in the assessment and classification of the fracture severity, as well as the presence of any associated dislocations. These fractures require surgical intervention for the restoration of joint function and the reduction of long-term complications. The paper aims to present the surgical correction and post-operative treatment of osteochondral fractures with absorbable implants in three children. Affected areas are discussed as follows: lateral condyle of the femur, patella, and radial head. Utilising absorbable implants for the management of OCFs provides numerous advantages, including the elimination of the need for reanaesthesia and reoperation, reducing complications, and enabling early rehabilitation. This approach also minimises the period of hospitalisation and proved effective in pediatric OCF treatment.
ARTICLE | doi:10.20944/preprints202310.1292.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Haemonchus contortus; rHcES-15; PLGA; nanoparticles; vaccination; mice
Online: 20 October 2023 (06:10:50 CEST)
Haemonchus contortus (H. contortus) is a gastrointestinal parasite affecting small ruminants, leading to a significant decline in animal productivity. In this study, we developed a nanovaccine by encapsulating the recombinant protein rHcES-15, derived from the excretory/secretory products of H. contortus, within biodegradable poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). To construct the nanovaccine, PLGA NPs were prepared using a modified double emulsion solvent evaporation technique. Scanning electron microscopy (SEM) illustrated successful encapsulation of rHcES-15 within PLGA NPs, with a size ranging between 350-400 nm. The encapsulation efficiency (EE) of the antigen in the nanovaccine was determined to be 72%. A total of forty experimental mice were divided into five groups, receiving the nanovaccine on day 0 and being humanely sacrificed at the end of the 14-day trial. The stimulation index (SI) from mice vaccinated with the nanovaccine indicated an amplified lymphocyte proliferation and a significant increase in anti-inflammatory cytokines (IL-4, IL-10, and IL-17). Furthermore, the percentages of T-cells (CD4+, CD8+) and dendritic cell phenotypes (CD83+, CD86+) were substantially upregulated in mice immunized with the nanovaccine compared to control groups and the rHcES-15 group. Similarly, higher levels of antigen-specific serum immunoglobulins (IgG1, IgG2a, IgM) were observed in response to the nanovaccine compared to both the antigenic (rHcES-15) and control groups. In conclusion, the data strongly supports the notion that encapsulation of rHcES-15 within PLGA NPs effectively stimulates immune cells in vivo, ultimately augmenting antigen-specific adaptive immune responses against H. contortus. This discovery highlights the promising potential of the nanovaccine, justifying additional investigations to ascertain its efficacy finally.
COMMUNICATION | doi:10.20944/preprints202104.0524.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: machine learning; Gaussian; nanoparticles; descriptors; docking; simulations; PLGA
Online: 20 April 2021 (09:47:24 CEST)
The objective of this study was to correlate the binding of drugs on a very popular nanoparticulate polymeric matrix; PLGA nanoparticles with their main constitutional, electronic and physico-chemical descriptors. Gaussian Processes (GPs) was the artificial intelligence machine learning method that was utilized to fulfil this task. The method could successfully model the results where optimum values of the investigated descriptors of the loaded drugs were deduced. A percentage bias of 12.68 % ± 2.1 was obtained in predicting the binding energies of a group of test drugs. As a conclusion, GPs could successfully model the drugs-PLGA interactions associated with a good predicting power. The GPs-predicted binding energies (ΔG) can easily be projected to the drugs loading as was previously proven. Adopting the “Pharmaceutics Informatics” approach can save the pharmaceutical industry and the drug delivery scientists a lot of exerted resources, efforts and time.
ARTICLE | doi:10.20944/preprints202011.0215.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Pancreatic Cancer; PLGA-PAA copolymer; Hydroxytyrosol; Curcumin; Apoptosis
Online: 5 November 2020 (14:51:15 CET)
Background and Aim: Pancreatic cancer (PC) is a highly aggressive malignancy associated with low survival rates. Many chemotherapeutic regimens have been investigated for advanced unresectable and metastatic PC, but with only minimal improvement in survival and prognosis. The present study aimed to investigate the anti-cancer function of free and nano-encapsulated hydroxytyrosol (Hyd) and curcumin (Cur), and its combinations (Hyd-Cur) on the PANC-1 cell line.Methods: The poly lactide-co-glycolide-co-polyacrylic acid (PLGA-co-PAA) nano-encapsulated Hyd and Cur were synthesized, and MTT assay was performed to evaluate cytotoxic effects of free and nano-encapsulated Hyd, Cur, and Hyd-Cur. Moreover, effects of free and nano-encapsulated Hyd, Cur, and Hyd-Cur were evaluated on viability, migration, morphological alterations, colony formation, and apoptosis on PANC-1 cell line. The mRNA expression levels of MMP2, MMP9, BAX, BCL-2, and Cas9 genes were assessed after treated PANC-1 cells with free and nano-encapsulated Hyd, Cur, and Hyd-Cur.Results: The obtained results showed that free and nano-encapsulated Hyd, Cur, and Hyd-Cur treatments significantly decreased the viability, migration, and colony formation in the PANC-1 cells. Furthermore, apoptosis rates in PANC-1 cells were increased in a concentration and time dependent manner in all of the treatment groups. Moreover, anti-proliferative activity of nano-encapsulated Hyd-Cur was significantly more than other treatments.Conclusion: According to our results, Hyd-Cur combination and nano-encapsulation therapy exerts more profound apoptotic and anti-proliferative effects on PANC-1 cell line than free Hyd or Hyd monotherapy.
ARTICLE | doi:10.20944/preprints202310.0299.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: API; PLGA nanoparticles; HA; CD44; colon cancer; targeted delivery
Online: 5 October 2023 (14:22:23 CEST)
Apigenin (API) possesses excellent antitumor properties, but its limited water solubility and low bioavailability restrict its therapeutic impact. Thus, a suitable delivery systems is needed to overcome these limitations and improve the therapeutic efficiency. Poly (lactic-co-glycolic acid) (PLGA) is a copolymer extensively utilized in drug delivery. Hyaluronic acid (HA) is a major extracellular matrix and can specifically bind with CD44 on colon cancer cells. Chitosan (CS) can serve as an intermediate binding with HA and PLGA. Herein, we aimed to perpare receptor-selective HA-coated PLGA nanoparticles (NPs) for colon cancer with high expression of CD44. Firstly, API was encapsulated in PLGA to obtain PLGA-API-NPs, which were then sequentially combined with CS and HA to form HA-coated PLGA NPs. HA coated PLGA NPs had a stronger sustained-release capability. Cellular uptake of HA coated PLGA NPs was enhanced in HT-29 cells with high expression of CD44. HA-PLGA-DiR-NPs can target specificity towards the HT-29 ectopic tumor model. Overall, HA coated PLGA NPs was an effectively drug deliver platform for API in treatment of colon cancer with high expression of CD44.
ARTICLE | doi:10.20944/preprints202309.0300.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Zn–B–PLGA biocomposite; DLS; SEM; DoE; UHPLC/MS
Online: 5 September 2023 (10:03:29 CEST)
Our concern was to obtain a biocomposite material with improved properties of the constituent materials (poly(lactic- co-glycolic acid) (PLGA) and zinc–boron (Zn–B) complex) in accordance with the novelties in the field of delivery systems for therapeutic agents which lately redefine the importance of biopolymer nanocomposites with PLGA (biodegradable composites). The advantages of such a biomaterial target the health system, being easy to obtain, through a cost-effective method. The water/oil/water double emulsion method also allows the adjustment of the synthesis parameters, to maximize the degree of Zn–B complex encapsulation. The morphological aspects of the samples (size, shape, porosity) were established by scanning electron microscopy (SEM). Particle size distribution (by volume and by number) was determined by direct light scattering (DLS). For all the synthesized materials, the observed morphology was typical for PLGA, spherical one. The particle size distribution showed that depending on the synthesis conditions, the particles can be obtained with diameters between 10–450 nm range and the value of the zeta potential (ZP) shows that the particles have electronegative surface charge, which offers a favorable perspective on the phenomena of aggregation, flocculation, dispersion. It was observed, applying the design of experiments (DoE), that the size of the particles increased with increasing amounts of PLGA and polyvinyl alcohol (PVA) in the formulation, while ZP increased with higher PLGA and smaller PVA. The encapsulation efficiency was determined by ultra-high performance liquid chromatography/mass spectrometry (UHPLC/MS).
ARTICLE | doi:10.20944/preprints202307.1878.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Microparticles; PEG; PLGA; coaxial flow; phase separation; drug delivery
Online: 27 July 2023 (09:38:27 CEST)
Polymeric microparticles of polyethyleneglycol-polylactic acid-co-glycolic acid (PEG-PLGA) are widely used as drug carriers for a variety of applications due to their unique characteristics. Herein, we developed a novel method for the synthesis of uniformly sized microparticles via coaxial flow-phase separation. The study evaluated the effect of various process parameters on microparticle size and polydispersity including polymer concentration, stirring rate, surfactant concentration, and the organic/aqueous phase flow rate and volume ratio. The results demonstrated that stirring rate and polymer concentration had the most significant impact on the mean particle size and distribution whereas surfactant concentration had the most substantial impact on the morphology of particles. Several microparticle formulations yielding particle sizes in the range of (5-50 µm), morphology, and concentration were synthesized as a demonstration of the tunability and scalability of this method. Notably, by controlling the process parameters microparticles of less than ~ 7 μm could be made using polymer concentrations varying by an order of magnitude. Finally, we demonstrated the tunability and scalability of this method by showing a 10-fold increase in encapsulation efficiency, a 3-fold increase in drug loading of a model hydrophilic drug, and modified release kinetics in microparticle formulations of comparable sizes but different polymer concentrations.
ARTICLE | doi:10.20944/preprints202306.0847.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: S-Allyl Cysteine; Oral Bioavailability; PLGA NPs; LC–MS/MS; Pharmacokinetics
Online: 12 June 2023 (14:09:39 CEST)
A newly UHPLC-MS/MS method development and validation for S-Allyl Cysteine was used to evaluate the comparative pharmacokinetic parameters. SC PLGA NPs were developed by the emulsion solvent evaporation method. SC PLGA NPs showed their drug loading and encapsulation efficiency i.e. 5.13±0.10% and 82.36±4.01%, respectively. SC PLGA NPs showed a spherical morphology on an average size (134.8±4.61nm), PDI: 0.277±0.004, and −25.3±1.03mV zeta-potential is suitable for oral delivery. Development and validation of the UHPLC-MS/MS bioanalytical method were performed successfully for PK-parameters examinations with 1.219-minutes RT, MS (162.00/73.10), and a total run-time was 2.0-minutes. 1.0–1000.0ng/mL was a linear-range with inter & intra-day accuracy (92.55–99.40%) followed by precision (1.88–4.23%). SC PLGA NPs oral bioavailability was significantly higher (**p<0.01) as compared to SC-S treated groups (iv & oral). We found that the antimicrobial activity of SC PLGA NPs was more effective than pure S-Allyl-L-Cysteine with significant results (p<0.01) as compared to SC-S. SC PLGA NPs showed fitted physicochemical and enhanced antimicrobial properties which can be helpful for oral administration. On the basis of our observations, SC PLGA NPs suggested the highest potential for the improvement of oral bioavailability with a sustained and controlled release of S-Allyl-L-Cysteine delivery.
ARTICLE | doi:10.20944/preprints202308.1277.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: sorafenib; PLGA; Pluronic F-127; Nanosuspension; in-vitro release and in-vivo pharmacokinetics
Online: 17 August 2023 (11:55:20 CEST)
The aim of this study is to improve the therapeutic effectiveness of the sorafenib loaded polymeric nanoparticles, surface modified by the pluronic F-127 for the treatment of hepatocellular (HCC) and renal cell carcinomas (RCC). Poly Lactic co-glycolic acid (PLGA) was used to encapsulate sorafenib by simple modified solvent evaporation technique. The nanoparticles were prepared with different concentration of sorafenib and pluronic F-127 keeping PLGA concentration constant. There were no incompatibilities among the sorafenib, PLGA and pluronic F-127 showing that the integrity of polymer, stabilizer and drug remain the same under different conditions. The size of the coated and plain PLGA nanoparticles were ~140 ± 14.7 nm and ~ 200 ± 10.1 nm, respectively. The in-vitro release studies demonstrated that the PLGA controlled the release of sorafenib, avoiding the initial burst release. The effect of coated and plain nanoformulations was found out in squamous cell carcinoma cells. The results showed that surface modified nanoparticles treated hepatocellular and renal carcinoma in a better way as compared to plain PLGA nanoparticles and free dug by keeping the dose constant (20 mg/kg body weight).The targeted delivery of polymeric PLGA nanoparticles into squamous cell carcinoma was improved. The pharmacokinetic parameters have been improved significantly as compared to the reported nanoformulations.
ARTICLE | doi:10.20944/preprints202104.0222.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: ocular surface disease; dry eye disease; antioxidant; Xanthohumol; drug delivery; drug formulation; PLGA; nanoparticles
Online: 8 April 2021 (09:09:24 CEST)
Elevated levels of oxidative stress in the corneal epithelium contribute to the progression of dry eye disease pathology. Previous studies have shown that antioxidant therapeutic intervention is a promising avenue to reduce disease burden and slow disease progression. In this study, we evaluated the pharmacological efficacy of Xanthohumol in preclinical models for dry eye disease. Xanthohumol is a naturally occurring prenylated chalconoid that promotes the transcription of phase II antioxidant enzymes. Xanthohumol exerted a dose-response in preventing tert-butylhydroxide-induced loss of cell viability in human corneal epithelial (HCE-T) cells and resulted in a significant increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of the endogenous antioxidant system. Xanthohumol-encapsulating poly(lactic-co-glycolic acid) nanoparticles (PLGA NP) were cytoprotective against oxidative stress in vitro, and significantly reduced corneal fluorescein staining in the mouse desiccating stress/ scopolamine model for dry eye disease in vivo by reducing oxidative stress-associated DNA damage in corneal epithelial cells. PLGA NP represent a safe and efficacious drug delivery vehicle for hydrophobic small molecules to the ocular surface. Optimization of NP-based antioxidant formulations with the goal to minimize instillation frequency may represent future therapeutic options for dry eye disease and related ocular surface disease.
ARTICLE | doi:10.20944/preprints202107.0503.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Cytotoxicity; Glioblastoma multiform; Lactate dehydrogenase (LDH); Poly D- L-lactic-co-glycolic acid (PLGA); U-87 MG glioma cell lines
Online: 21 July 2021 (16:37:21 CEST)
PHLNs (polymeric lipid hybrid nanoparticles) are core–shell nanoparticle structures made up of polymer cores and lipid shells that have properties similar to both polymeric nanoparticles and liposomes. Methotrexate (MTX) loaded PLHNPs containing tween 80, phosphatidylcholine, poly D, L-lactic-co-glycolic acid (PLGA) & glyceryl tripalmitate prepared using solvent injection & homogenization method for glioblastoma treatment option. The MTX loaded PLHNPs optimized by Box–Behnken design to minimize particle size, higher entrapment efficacy, and maximize MTX concentration in the brain at 4h. The particle size, entrapment efficacy, concentration of drug in brain at 4h, zeta potential and AUC(Brain)/AUC(Plasma) ratio were in the range of 173.51-233.37nm, 70.56-86.34%, 6.38-12.38 μg/mL, 25.78-36.31mV & 1.02-5.32. in-vitro drug release studies, cellular internalization of optimized formulation against U-87 MG shows good anticancer effects.