Fig. 9

pH-responsive hyaluronic acid/platelet-rich plasma hydrogel containing MnO2 nanozymes. A Schematic illustration showing the injectable hydrogel of HA/PRP/BM fabricated via Schiff base reaction, and its synergetic treatment of osteoarthritis owing to visco-supplementation, ROS elimination, inflammation relief, and cartilage repair promotion. B The cumulative release profile of total protein from the HA/PRP hydrogel in PBS with different pH values. V The cumulative release profile of TGF-β1 from the HA/PRP hydrogel in PBS with different pH values. D The cumulative release profile of BM from HA/BM hydrogel in PBS with different pH values. E Representative images of HE staining, Safranin O-fast green staining, and collagen II protein immunohistochemical staining from each group. Scale bars, 200 μm. F Total Mankin score of articular cartilage. n = 5. *p < 0.05 and ***p < 0.001 versus OA group. # and ### indicate p < 0.05 and p < 0.001 between the selected groups. Copyright 2022, Elsevier