Facile control of RGD-alginate/hyaluronate hydrogel formation for cartilage regeneration

Hydrogels are attractive carriers for delivery of cells in tissue engineering as cell/polymer constructs can be injected into the body in a minimally invasive manner. In this study, we prepared hydrogels using only RGD-alginate and hyaluronate in the presence of primary chondrocytes without additional chemical cross-linking reagents. RGD peptides were introduced to alginate chains to increase the specific interactions with cells, and hyaluronate was used to enhance the cellular interactions and resultant gel formation. The gelation of RGD-alginate/hyaluronate hydrogels was confirmed by rheological measurements. These gels were useful to regenerate cartilage tissues in vivo, which was confirmed by analysis of glycosaminoglycan secretion and chondrogenic gene expression in both qualitative and quantitative manner. This approach to controlling the gelation behavior using only cells and cell-interactive polymers could be useful for delivery of cells and therapeutics in biomedical applications.