Biodegradable glass fiber reinforced PVA hydrogel for cartilage repair: mechanical properties, ions release behavior and cell recruitment

Articular cartilage with limited ability of regeneration remains a grand challenge in the field of tissue engineering. Poly(vinyl alcohol) (PVA) hydrogel with low friction coefficient have been regarded as prior candidate for cartilage substitute, whereas lack of structure performance and bioactivity limited their application. Phosphate glass fiber (PGF) with outstanding mechanical performance and nature of biodegradability presents potential capability to improve mechanical stability of hydrogel and chondrocyte metabolism as well as cell recruitment. Herein, we describe a novel PGF-PVA composites hydrogel incorporated with continuous PGF. The presence of stiff PGF not only improves the mechanical properties of hydrogel with maximum tensile strength of 12.44 MPa and Young's modulus of 68.35 MPa, but also endows the hydrogel molecular structure with the increase of crystallinity and thermal stability via formation of crosslinking points. More importantly, the PVA hydrogel matrix exhibits efficient ions exchange behavior to control ions concentration during PGF degradation, resulting in more suitable metabolic environment for chondrocyte proliferation and induction with enhanced recruitment. Therefore, it is believed that this work provides a kind of fiber reinforced hydrogel material promising excellent properties for cartilage repair.