Self-crosslinking and injectable hyaluronic acid/RGD-functionalized pectin hydrogel for cartilage tissue engineering.

In the present study, we developed a biomimetic injectable hydrogel system based on hyaluronic acid-adipic dihydrazide and the oligopeptide G4 RGDS-grafted oxidized pectin, in which their hydrazide and aldehyde-derivatives enable covalent hydrazone crosslinking of polysaccharides. The hydrazone crosslinking strategy is simple, while circumventing toxicity, making this injectable system feasible, minimally invasive and easily translatable for regenerative purposes. By varying their weight ratios, the physicochemical properties of the mechanically stable hydrogel system were easily adjustable. Additionally, the preliminary studies demonstrated that chondrocyte behavior was dependent on HA/pectin composition and the presence of integrin binding moieties. Specifically, the incorporation of a certain amount of G4 RGDS oligopeptide into HA/pectin-based hydrogels could serve as a biologically active microenvironment that supported chondrocyte phenotype and facilitated chondrogenesis. Furthermore, the hydrogel system exhibited acceptable tissue compatibility by using a mouse subcutaneous implantation model. Overall, the novel injectable multicomponent hydrogel presented here is expected to be useful biomaterial scaffold for cartilage tissue regeneration.