93 research outputs found
Polyvinyl alcohol-poly(caprolactone) semi IPN scaffold with implication for cartilage tissue engineering
No full textPolycaprolactone is an FDA approved aliphatic polyester that is widely used as a scaffold for tissue engineering. It is hydrophobic and doesn't have any reactive functional groups on the polymer for further modification. Blending with other hydrophilic polymers like polyvinyl alcohol helps to generate a hybrid polymer with better properties. In this study we have been able to fabricate a novel porous 3D scaffold of Semi-IPN Poly (caprolactone)-Poly (vinyl alcohol). The Semi IPN is phase mixed and has synergistic properties of its constituent polymers. The hybrid scaffold is nontoxic and highly hydrophilic with greater percentage of swelling and is also amenable for further modification with bioactive peptides. Although porous with an open interconnected porous structure, the scaffold has adequate mechanical strength to withstand the load imparted by the cells during in vitro culture. Porcine chondrocytes seeded within the unmodified scaffolds secrete extra cellular matrix components revealing that the hybrid scaffold has immense potential for tissue engineering applications. (C) 2007 Wiley Periodicals, Inc
A Synthetic Scaffold Favoring Chondrogenic Phenotype over a Natural Scaffold
No full textThe three-dimensional scaffolds play a very important role in regulating cell adhesion and the production of extracellular matrix molecules in in vitro regeneration of cartilage. This study evaluates how the three-dimensional structure and physicochemical properties of the polymeric scaffolds influence in vitro regeneration of cartilage tissue. A synthetic poly(vinyl alcohol)-poly(caprolactone) semi-interpenetrating polymer network (IPN) scaffold and gelatin-albumin, made of natural polymers, are used for the study. The polymers in the semi-IPN synthetic scaffold mimic the properties of collagen and glycosaminoglycans present in native cartilage. Its appropriate swelling and pore structure enabled cell-cell and cell-matrix interactions. This helped the chondrocytes to retain its spherical morphology and resulted in enhanced secretion of extracellular matrix components. In contrast, the biomimetic structure in gelatin-albumin scaffold induced chondrocytes to loose its phenotype by spreading and becoming fibroblastic in morphology. Its high swelling and the large pore size failed to recreate an appropriate microenvironment for chondrogenesis that resulted in less secretion of cartilage-specific molecules. Mesenchymal stem cell differentiation to chondrocytes in the presence of growth factors is also enhanced in the synthetic semi-IPN scaffold. The study thus indicates that the chemical composition and the physicochemical properties of the scaffolds play a very important role in providing appropriate niche in in vitro tissue regeneration
A 3D biodegradable protein based matrix for cartilage tissue engineering and stem cell differentiation to cartilage.
No full textA protein based 3D porous scaffold is fabricated by blending gelatin and albumin. The biomimetic biodegradable gelatin, promoted good cell adhesion and its hydrophilic nature enabled absorption of culture media. Albumin is proposed to serve as a nontoxic foaming agent and also helped to attain a hydrophobic-hydrophilic balance. The hydrophobic-hydrophilic balance and appropriate crosslinking of the scaffold avoided extensive swelling, as well as retained the stability of scaffold in culture medium for long period. The scaffold is found to be highly porous with open interconnected pores. The adequate swelling and mechanical property of the scaffold helped to withstand the loads imparted by the cells during in vitro culture. The scaffold served as a nontoxic material to monolayer of fibroblast cells and is found to be cell compatible. The suitability of scaffold for chondrocyte culture and stem cell differentiation to chondrocytes is further explored in this work. The scaffold provided appropriate environment for chondrocyte culture, resulting in deposition of cartilage specific matrix molecules that completely masked the pores of the porous scaffold. The scaffold promoted the proliferation and differentiation of mesenchymal stem cells to chondrocytes in presence of growth factors. The transforming growth factor, TGFbeta3 promoted better chondrogenic differentiation than its isoform TGFbeta1 in this scaffold
Growth factor-mediated effects on chondrogenic differentiation of mesenchymal stem cells in 3D semi-IPN poly(vinyl alcohol)-poly(caprolactone) scaffolds
No full textCells, signaling molecules and three-dimensional (3D) scaffolds are the major contributors to the in vitro regeneration of cartilage. This study evaluates the differentiation of mesenchymal stem cells to chondrocytes, in a 3D semi-interpenetrating polymer network (semi-IPN) scaffold that gives an appropriate niche for chondrogenic differentiation. The 3D semi-IPN scaffold poly(vinyl alcohol) and poly(caprolactone) mimics the properties of extracellular matrix of native cartilage. The chondrogenic differentiation of mesenchymal stem cells on the 3D scaffolds is carried out by supplementing signaling molecules like TGF beta 1, TGF beta 3, and BMP2 individually and in two different combinations. The results indicate that each growth factor supplement or combinations showed a different influence on cell morphology, overall distribution of cells, and secretion of cartilage specific molecules. We conclude from our results, that a combination of TGF beta 3 and BMP2 promotes better differentiation of mesenchymal stem cells to chondrocytes in our scaffold. This study hence points out that an appropriate combination of 3D scaffolds and signaling molecules are required in the differentiation and maintenance of the chondrogenic phenotype during in vitro regeneration of cartilage tissue. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res 94A: 146-159, 201
A Study on Occupational Stress among Railway Employees with Special Reference to Thrissur Railway Station
No full textIndian railway is one of the income generating industries in India. The industry is a success because of its efficient staff. They are valuable assets of the industry and the key to success. The employees in the Indian railway are experiencing a tremendous amount of pressure at the work place. Increased workloads, overtime, hostile work environment and shift work are just a few causes of stressful working conditions. In such a situation it is necessary to study the occupational stress of railway employees because if not controlled, it can affect the person’s family or social life, health, performance etc. hence in the study an attempt has been made to find out the major sources and causes of stress and gather knowledge about the techniques to lower stress. The results of the study show that the employees are facing stressful situations in their work place and they are well aware of the techniques to lower stress.</jats:p
Integrated Pharmacoepigenomic Analysis Uncovers the Impact of Antiseizure Medications on Developmental Pathways and the Protective Effect of Folic Acid
No full textFetal exposure to antiseizure medications (ASMs) can impact organogenesis, resulting in elevated risk of congenital malformations. Despite longstanding clinical awareness of the teratogenic potential of ASMs, the molecular mechanisms remain largely unexplored. To address this multisystem impact of ASMs, an OMIC-based approach was considered to understand the impact of ASMs on methylome and subsequently on proteome and how folic acid (FA) supplementation can counter the teratogenic impact. The study employed an established in vitro embryonic cell line model system, treated with varying concentrations of first-generation ASMs, alone and in combination with FA. Integrated analyses included quantification of global DNA methylation, expression analysis of key epigenetic regulators (DNMTs and TETs), genome-wide methylation profiling using the 935K EPIC array, and LC-MS/MS-based proteomics analysis. The study identified that ASMs can induce global DNA hypomethylation, which was likely to be impacted by dysregulation of DNMT and TET expression. Interestingly, FA co-treatment partially restored DNA methylation as evidenced by global DNA methylation and epigenetic gene expression, and also by compensatory effect via one-carbon metabolism. Genome-wide DNA methylation revealed site-specific hypermethylation at key developmental genes, several of which were reversed with FA. Proteomics analysis identified downregulation of developmentally critical proteins, including those linked to key metabolic processes, while FA co-treatment reversed expression of several such proteins. Integrative methylome–proteome analysis revealed the coordinated regulation of target genes that are linked to congenital abnormalities. Together, these findings offer mechanistic insight into ASM-induced teratogenesis and support FA’s potential to mitigate epigenetic and proteomic disruptions. This integrated OMICs based approach identifies key biomarkers which can be used for therapeutic monitoring and help in optimizing maternal epilepsy management
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