ARTICLE | doi:10.20944/preprints201806.0047.v1
Subject: 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: 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.
COMMUNICATION | doi:10.20944/preprints202104.0524.v1
Subject: 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 & Pharmacology, Allergology 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/preprints202104.0222.v1
Subject: Medicine & Pharmacology, Allergology 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 & Pharmacology, Allergology 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.