Investigation the influence of ar plasma treatment on cell response for wet-spun starch/polycaprolactone fiber mesh scaffolds

In design of a tissue engineering scaffold, surface physicochemistry is one of the most important issues to be considered. The physicochemical properties of the surface directly influence the scaffold performance by affecting the cellular response and ultimately effecting the new tissue formation. In order to improve the cell affinity, the surface hydrophiliticy, surface energy, surface roughness and surface charge can be modify by different methods. Plasma treatment is a versatile method for surface treatment of biodegradable polymers without altering their bulk properties. By this method, it is possible to introduce or graft desired functional groups onto the surface. This study aims to investigate the influence of Ar plasma treatment on osteablast cell response for fiber mesh scaffolds from a starch-polycaprolactone blend. [...]info:eu-repo/semantics/publishedVersio

Nano/microparticle incorporated chitosan fibers as tissue engineering scaffolds

[Excerpt] The aim of this study was to develop a bone tissue engineering scaffold with an inherent bone morphogenetic proteins BMP-2 and BMP-7 sequential delivery system. BMPs were encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(lactic acid-co-glycolic acid) (PLGA) nano/microparticules which are then introduced to a chitosan matrix by two methods: embedding in the chitosan fibers and then forming the scaffold or by forming the chitosan scaffold and then introducing the nano/microparticules. [...]info:eu-repo/semantics/publishedVersio

Osteogenic differentiation of mesenchymal stem cells cultured on PLLA scaffold coated with Wharton's jelly

Poly-L-lactic acid (PLLA) electrospun nanofiber scaffold is one of the most commonly used synthetic polymer scaffolds for bone tissue engineering application. However, PLLA is hydrophobic in nature, hence does not maintain proper cell adhesion and tissue formation, moreover, it cannot provide the osteo-inductive environment due to inappropriate surface characteristic and the lack of surface motives participating in the first cellular events. To modify these shortcomings different approaches have been used, among those the most commonly used one is coating of the surface of the electrospun nanofiber with natural materials. In this work Wharton’s jelly (WJ), a tissue which surrounds the umbilical cord vessels, reaches in high amounts of extracellular matrix (ECM) components mainly; collagen, hyaluronic acid and several sulphated glycosaminoglycans (GAGs) were used to cover the surface of electrospun PLLA nanofiber scaffolds. The surface morphology of the nanofiber scaffold was evaluated via scanning electron microscope, and the in vitro osteogenic differentiation potential was determined by MTT assay and common osteogenic marker tests such as alkaline phosphatase (ALP) activity and calcium deposition tests. Coating of WJ could not change the surface morphology and diameter of the nanofibers. However, WJPLLA scaffolds showed higher proliferation of human mesenchymal stem cells (MSC) than tissue culture plate (TCP) and pristine PLLA scaffolds, moreover, WJ-PPLA scaffold demonstrated significant alkaline phosphatase activity and calcium mineralization than either TCP or PLLA nanofiber scaffolds

A novel enzymatically-mediated drug delivery carrier for bone tissue engineering applications: combining biodegradable starch-based microparticles and differentiation agents

In many biomedical applications, the performance of biomaterials depends largely on their degradation behavior. For instance, in drug delivery applications, the polymeric carrier should degrade under physiological conditions slowly releasing the encapsulated drug. The aim of this work was, therefore, to develop an enzymaticmediated degradation carrier system for the delivery of differentiation agents to be used in bone tissue engineering applications. For that, a polymeric blend of starch with polycaprolactone (SPCL) was used to produce a microparticle carrier for the controlled release of dexamethasone (DEX). In order to investigate the effect of enzymes on the degradation behavior of the developed system and release profile of the encapsulated osteogenic agent (DEX), the microparticles were incubated in phosphate buffer solution in the presence of a-amylase and/or lipase enzymes (at physiological concentrations), at 37 C for different periods of time. The degradation was followed by gravimetric measurements, scanning electron microscopy (SEM) and Fourier transformed infrared (FTIR) spectroscopy and the release of DEX was monitored by high performance liquid chromatography (HPLC). The developed microparticles were shown to be susceptible to enzymatic degradation, as observed by an increase in weight loss and porosity with degradation time when compared with control samples (incubation in buffer only). For longer degradation times, the diameter of the microparticles decreased significantly and a highly porous matrix was obtained. The in vitro release studies showed a sustained release pattern with 48% of the encapsulated drug being released for a period of 30 days. As the degradation proceeds, it is expected that the remaining encapsulated drug will be completely released as a consequence of an increasingly permeable matrix and faster diffusion of the drug. Cytocompatibility results indicated the possibility of the developed microparticles to be used as biomaterial due to their reduced cytotoxic effects

Novel biodegradable polymeric microparticles for the localized delivery of differentiation agents in bone tissue engineering applications

[Excerpt] Growth and differentiation factors can be used to guide the biology in tissue engineering, ranging from promoting cell proliferation, to morphogenic activities initiating a cascade of events leading to tissue formation in vivo. Synthetic glucocorticoids (e.g. dexamethasone, DEX) and bone morphogenetic proteins (BMPs) are particularly relevant in bone tissue engineering, as they are able to induce osteoblastic differentiation. In this work, starch-poly-e-caprolactone (SPCL) microparticles were developed as a matrix for the controlled release of DEX and BMP-2. The developed system was characterized in terms of morphology and size distribution. DEX and BMP-2 were entrapped into SPCL microparticles at different percentages. The loading and encapsulation efficiency, as well as their release profile, were evaluated by HPLC and ELISA quantification. [...]info:eu-repo/semantics/publishedVersio