Effects of Chitosan-Gelatin Hydrogels on Fibro-Chondrogenesis

Abstract

The objective of this study was to investigate a hydrogel system that is easy to utilize in the clinical settings to produce cartilage and an autologous cell source for chondrocytes such as easily available human foreskin fibroblasts (hFF-1). Evidence of a decrease in gelation point as an increase in concentration was displayed from the rheology data, which was consistent with previous studies. Increase in chitosan and gelatin concentrations significantly increased the elastic modulus to be within the necessary limits of naturally cartilage. Analysis of the cell shape and size factor suggested the possibility of differentiation of fibroblasts into chondrocytes when compared to the differentiation of hMSCs into chondrocytes. From the ELISA analysis, collagen type II secretion into the medium was higher in hydrogels than for the pellet cultures. Additionally, collagen content was observed to be at a maximum on day seven and was determined to be due to components in the medium and not due to gelatin leaching. Flow cytometry profiles demonstrate alternations in CD44 and CD151 expression. Analysis of the histology showed an increase in matrix accumulation in the structures as well as cell to matrix interaction and embedding. Analyses of MMP-2/MMP-9 and MMP-13 showed similarity between fibroblasts and hMSC cultures.