Enhanced chondrogenesis of mesenchymal stem cells over silk fibroin/chitosan-chondroitin sulfate three dimensional scaffold in dynamic culture condition.

Chondroitin sulfate (Ch) is one of the main structural components of cartilage tissue, therefore, its presence in tissue engineered scaffold is expected to enhance cartilage regeneration. Previously, silk fibroin/chitosan (SF/CS) blend was proven to be a potential biomaterial for tissue development. In this study, the effect of Ch on physicochemical and biological properties of SF/CS blend was investigated and scaffolds with 0.8 wt% Ch was found to be favorable. The scaffolds possess pore size of 37-212 µm, contact angle 46.2-50.3°, showed controlled swelling and biodegradation. The biocompatibility of scaffold was confirmed by subcutaneous implantation in mouse. Human mesenchymal stem cells (hMSCs) seeded scaffolds cultured under spinner flask bioreactor promoted cell attachment, proliferation, distribution, and metabolic activity in vitro. The histology and immunofluorescence studies revealed that combined effect of Ch and dynamic condition resulted in higher glycosaminoglycan secretion and native cartilage type matrix synthesis in comparison to SF/CS scaffolds used as control. Higher expression of collagen-II, Sox9, aggrecan and decrease in collagen-I expression represented by quantitative polymerase chain reaction study confirmed the progression of chondrogenic differentiation. This study successfully demonstrates the potentiality of SF/CS-Ch scaffold for hMSCs recruitment and redirecting cartilage tissue regeneration with enhanced chondrogenesis.