Search results for " chitosan"

Human platelet-rich plasma improves the nesting and differentiation of human chondrocytes cultured in stabilized porous chitosan scaffolds

2017

[EN] The clinical management of large-size cartilage lesions is difficult due to the limited regenerative ability of the cartilage. Different biomaterials have been used to develop tissue engineering substitutes for cartilage repair, including chitosan alone or in combination with growth factors to improve its chondrogenic properties. The main objective of this investigation was to evaluate the benefits of combining activated platelet-rich plasma with a stabilized porous chitosan scaffold for cartilage regeneration. To achieve this purpose, stabilized porous chitosan scaffolds were prepared using freeze gelation and combined with activated platelet-rich plasma. Human primary articular chond…

Synchronizing the release rates of salicylate and indomethacin from degradable chitosan hydrogel and its optimization by definitive screening design.

2018

Abstract Three types of ionically crosslinked (with citric acid) chitosan discs were loaded with the highly water- soluble drug, sodium salicylate (SS) and the poorly water-soluble drug, indomethacin (Ind). In separate experiments the hydrated discs were immersed in a de-crosslinking solution comprising of different concentrations of calcium chloride, which induced a controlled erosion of the discs, a process which was optimized to synchronize the release rates of the two drugs over a predetermined period of time. The optimization was accomplished by manipulating six factors: chitosan MW, its amount in the formulation, the concentration of the crosslinker agent, the concentration of the de-…

3D-printing-assisted fabrication of chitosan scaffolds from different sources and cross-linkers for dental tissue engineering

2021

The aim of the present study was to fabricate and characterise chitosan scaffolds from animal and fungal sources, with or without gelatine as a co-polymer, and cross-linked to 3-glycidyloxyproply trimethoxysilane (GPTMS) or genipin for application in dental root tissue engineering. Chitosan-based scaffolds were prepared by the emulsion freeze-drying technique. Scanning electron microscopy (SEM) and nano-focus computed tomography (nano-CT) were used to characterise scaffold microstructure. Chemical composition and cross-linking were evaluated by Fourier transform infrared-attenuated total reflectance spectroscopy. Compression tests were performed to evaluate scaffold mechanical properties. S…

Effect of TiO2 and Al2O3 Addition on the Performance of Chitosan/Phosphotungstic Composite Membranes for Direct Methanol Fuel Cells

2023

Composite chitosan/phosphotungstic acid (CS/PTA) with the addition of TiO2 and Al2O3 particles were synthesized to be used as proton exchange membranes in direct methanol fuel cells (DMFCs). The influence of fillers was assessed through X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, liquid uptake, ion exchange capacity and methanol permeability measurements. The addition of TiO2 particles into proton exchange membranes led to an increase in crystallinity and a decrease in liquid uptake and methanol permeability with respect to pristine CS/PTA membranes, whilst the effect of the introduction of Al2O3 particles on the characteristics of membranes is almost the op…

Morphogenetically active scaffold for osteochondral repair (Polyphosphate/alginate/N,O-carboxymethyl chitosan)

2016

Here we describe a novel bioinspired hydrogel material that can be hardened with calcium ions to yield a scaffold material with viscoelastic properties matching those of cartilage. This material consists of a negatively charged biopolymer triplet, composed of morphogenetically active natural inorganic polyphosphate (polyP), along with the likewise biocompatible natural polymers N,O-carboxymethyl chitosan (N,O-CMC) and alginate. The porosity of the hardened scaffold material obtained after calcium exposure can be adjusted by varying the pre-processing conditions. Various compression tests were applied to determine the local (nanoindentation) and bulk mechanical properties (tensile/compressio…

Lipid Nanocarriers-Loaded Nanocomposite as a Suitable Platform to Release Antibacterial and Antioxidant Agents for Immediate Dental Implant Placement…

2021

Immediate implant placement is a single-stage restorative approach for missing teeth widely used to overcome the ridge remodeling process occurring after dental extractions. The success of this procedure relies on opportune osseointegration in the surrounding tissues. To support this process, a multifunctional nanocomposite, to be applied in the fresh post-extraction socket, was here designed, prepared, and characterized. This formulation consists of quercetin (QRC)-loaded nanostructured lipid carriers (NLCs) entrapped in a chitosan-based solid matrix containing ciprofloxacin (CPX). QRC-NLCs were prepared by homogenization followed by high-frequency sonication, and thereafter this dispersio…

Fabrication of Chitosan-Silver Nanoparticles composite coatings by galvanic deposition for orthopaedic implants

Composizione per uso nella finitura, conservazione, restauro di manufatti

2017

L’invenzione è relativa ad una composizione per il consolidamento e la conservazione di fibre tessili basata sull’impiego di un nano materiale in associazione con un agente di supporto. Il nano materiale è la nano fibroina e il materiale di supporto è preferenzialmente il chitosano, ma si possono impiegare altri materiali di analoghe prestazioni. La composizione trova applicazione nell’ambito della conservazione e restauro di materiali tessili, in quanto permette la riparazione di fibre e tessuti danneggiati, ripristinando le proprietà meccaniche, e la protezione da processi foto-ossidativi dei manufatti tessili in generale. Ulteriore campo di applicazione è quello del finissaggio di fibre …

Galvanic Deposition of Hydroxyapatite/Chitosan/Collagen Coatings on 304 Stainless Steel

2021

The galvanic deposition method was used to deposit Hydroxyapatite/Chitosan/Collagen coatings on 304 stainless steel. Galvanic deposition is an alternative and valid way to fabricate bio-coatings with high biocompatibility and good anticorrosion properties. Physical-chemical characterizations were carried out to investigate chemical composition and morphology of the samples. Coatings consist of a mixture of calcium phosphate (Brushite and Hydroxyapatite) with chitosan and collagen. Corrosion tests were performed in the simulated body fluid (SBF) after different aging times. Results show that, in comparison with bare 304 stainless steel, coating shifts corrosion potential to anodic values and…

Effects of foliar application of glycine betaine and chitosan on Puccinellia distans (Jacq.) Pari, subjected to salt stress.

2019

Introduction:Using brackish water for irrigation may expose turfgrasses to salinity stress.Employing the best treatments to maintain high-quality turfs under saline conditions is animportant requirement for turfgrass management.Methods:We tested the response of ahalophyte grass,Puccinellia distans, to irrigation with saline solutions and to foliarapplication of two osmoprotectants, such as glycine betaine (GB) or chitosan (CH). Plantswere grown in pots under controlled conditions and irrigated with 200 mM or 600 mM ofNaCl solutions. The response to salinity treatments and osmoprotectant application wasevaluated after 90 days by measuring leaffiring, leaf density, shoot length and biomass, r…