Novel bioactive glass cross-linked PVA hydrogel with enhanced chondrogenesis properties and application in mice chondrocytes for cartilage repair

The synthetic hydrogel owns huge potential and broad prospects in cartilage tissue engineering due to a series of unique properties, such as bioactivity, the nutrition ions release ability, high mechanical properties and chondrogenesis capacity. Bioactive glass (BG) and PVA have been widely investigated and reported with safety and excellent biocompatibility as tissue engineering materials. In this study, we have synthesized a novel composite hydrogel formed by crosslinking between bioactive glass and PVA for cartilage repair, furthermore, we have explored the reaction mechanism of this hydrogel. It was found that hydrogen bonding was formed by the hydroxyl groups in PVA combining with the oxygen atoms from the non-bridge Si-O bond in bioactive glass, which can explain better mechanical properties for PM group than that of PVA. The tensile and compressive stress of PM5 hydrogel group has reached 4.8 MPa and 1.8 MPa equaling mechanical properties of natural articular cartilage. Moreover, the hydrogel can significantly support the proliferation of mice chondrocytes in vitro. Meanwhile, it can also effectively upregulate the expression of chondrogenesis related genes (AGGRECAN, SOX9, COL2). Therefore, the novel hydrogel possesses excellent properties in cartilage repair, and exhibits potential medical applications in the future.