Di-Self-Crosslinking Hsmssa Hydrogel Combined with Colⅰ Constructed Biomimetic Injectable Cartilage Filling Scaffold

Injectable hydrogels have attracted increasing attention because of convenient clinical operation, non-invasive surgical procedure and seamless filling of irregular defects. Here, injectable di-self-crosslinking HSMSSA hydrogel was formed via fast thiol/maleimide click chemistry reaction and thiol oxidation reaction as primary and secondary self-crosslinking network, respectively. Molecular weight and precursor concentration significantly affected physichemical properties and biological functions of hydrogels. Although this HSMSSA gel (0.1M, 10 mg/mL) had excellent injectability, collagen-like mechanical properties and optimal chondrocytes proliferation efficiency in vitro, and could greatly promote cartilaginous tissue formation in vivo, the lack of adhesion sites resulted in an untenable situation in maintaining effective connections among newborn cell clusters. However, the biomimetic injectable di-self-crosslinking blend hydrogel by combined injectable HSMSSA and bioactive Col I presented excellent biological function in biocompatibility, resistance to degradation, chondrocytes adhesion and proliferation, especially for multiples ascending genes expression level associated with hyaline cartilage formation and polyproteoglycan secretion, which might be an excellent potential clinical treatment strategy for constructing injectable cartilage repair filler by combining expanded autologous chondrocytes.