Development and Characterization of Dual Growth Factor Loaded In Situ Gelling Biopolymeric System for Tissue Engineering Applications

In the past few decades, use of biodegradable scaffolds for tissue regeneration has emerged as a promising therapeutic approach with considerable success at clinical levels. The following study describes development of one such system—an in situ gelling minimally invasive system using bacterial polysaccharides—Gellan and Xanthan as scaffolds for various tissue engineering applications. Gelation time studies for Gellan: Xanthan hydrogels was carried out to determine the most suitable ratio of the two gel components such that the gel mixture should remain a low viscosity fluid at room temperature but should form a highly viscous gel upon injection at the injury site (i.e., at body temperature) within a few minutes. The porous microstructure of the gels was observed by scanning electron micrographs (SEM) and transmission electron microscopy (TEM). A dual growth factor release system with platelet derived growth factors (PDGF-BB) and basic fibroblast growth factor (bFGF) was developed where growth factors were encapsulated within chitosan nanoparticles embedded in the gels as well as directly within the gel. Adipose tissue derived stem cell (ADSC) differentiation and production of glycosaminoglycans (GAG) was observed within 7 days as was tested by safranin-O staining. MTT assay showed >90% viability for both L929 fibroblasts and ADSCs.