A mini-invasive injectable hydrogel for temporomandibular joint osteoarthritis: Its pleiotropic effects and multiple pathways in cartilage regeneration

There are two bottlenecks in the treatment of TMJOA (temporomandibular joint osteoarthritis): ① lacking of easy-to-use repairing materials for damaged condylar cartilage; ② local inflammation interfering with in situ regeneration. In response to them, we constructed a biomimetic tilapia type I gelatin/hyaluronic acid (TGI/HA) hydrogel in this paper. It was endowed with the capability to immunoregulate mircoenvironment and concurrently induce regeneration in multiple ways. It not only reduced excretion of ECM-degrading enzymes and inflammatory factors, therefore reversing local inflammation, but also created microenvironment conducive to reparation by acting upon macrophages and T cells. In in vivo experiments, the TGI/HA hydrogel effectively restored the damaged cartilage on rat condyle, suggesting it had potential in clinical application.