Soyasaponin Bb/Gelatin-Methacryloyl Hydrogel for Cartilage Inflammation Inhibition

The main causes of failure for cartilage tissue engineering implants are tissue integration, inflammation, and infection. The development of biomaterials with antiforeign body response (FBR) is of particular importance. Herein, we developed a hydrogel loaded with anti-inflammatory drugs to reduce the inflammatory response that follows implantation. The human chondrocytes were used for in vitro study, and cell-laden hydrogel samples were implanted with the backs of rabbits for in vivo study. Soyasaponin Bb (SsBb) as a traditional Chinese medicine could significantly (P < 0.05) downregulate the expression levels of inflammation-related markers including iNOS, COX-2, and IL-6 in chondrocytes induced by IL-1β through the NF-κB signaling pathway. The in vitro experiments demonstrated that a gelatin-methacryloyl (GelMA) hydrogel loaded with SsBb (SsBb/GelMA) could similarly reduce the gene and protein expression levels of inflammation-related markers (iNOS, COX-2, and IL-6). The in vivo anti-inflammatory effects of the SsBb/GelMA hydrogels were assessed by immunohistochemical staining. The results demonstrated that SsBb/GelMA hydrogels inhibited the inflammatory response and downregulated the expression of the inflammatory cytokine IL-6. Therefore, SsBb/GelMA hydrogels are promising candidates for promoting anti-inflammation and cartilage tissue regeneration of implant surfaces.