A hyaluronic acid/platelet-rich plasma hydrogel containing MnO2 nanozymes efficiently alleviates osteoarthritis in vivo

The osteoarthritis (OA) symptoms cannot be fully remedied by using only a single functional component because of its complex pathogenesis. Herein, a MnO2 nanozyme-encapsulated hydrogel was fabricated via dispersing bovine serum albumin (BSA)-MnO2 (BM) nanoparticles (NPs) into a hyaluronic acid (HA)/platelet-rich plasma (PRP) gel network crosslinked by Schiff base reaction. Due to the self-healing and pH-responsive properties of Schiff base bonds, the hydrogel not only functioned as viscosupplementation but also exhibited pH-responsive release of BM NPs and growth factors in PRP. The BM NPs could attenuate the severe oxidative stress, and the PRP could promote chondrocyte proliferation. In a rat OA model, the HA/PRP/BM hydrogel markedly suppressed cartilage matrix degradation. Both the in vitro and in vivo studies showed that this novel hydrogel platform could inhibit the development of osteoarthritis through a synergetic effect of mechanical dissipation, depressing inflammation, facilitating cartilage repair, and thus has essential application prospects in OA treatment.