Poly(vinyl alcohol) Hydrogels for Osteoarthritis: A Review of Preparation Strategies, Modification Approaches, and Challenges.

Articular cartilage has attracted significant attention for its essential roles in joint lubrication and stress buffering. However, its inherent self-repair capacity is limited. Addressing inflammatory damage to this tissue, therefore, presents a major clinical challenge in orthopedics. Poly(vinyl alcohol) (PVA)-based hydrogels have emerged as promising repair materials due to their high water content, which mimics the properties of natural cartilage, as well as their tunable mechanical properties and favorable biocompatibility. This review comprehensively examines PVA-based hydrogels, beginning with an overview of their network formation. It then systematically summarizes the main methods and principles for constructing their networks, including physical crosslinking (e.g., cyclic freezing-thawing), chemical crosslinking, and radiation crosslinking, as well as targeted strategies to enhance performance and modify functionality. Particular emphasis is placed on their diverse clinical applications in treating osteoarthritis, primarily including their use as surgical adjuncts, such as injectable gels and anti-adhesion membranes, as long-term or biodegradable cartilage replacement implants, and their potential in partial joint surface resurfacing and reconstruction. Finally, prospects for the application of PVA-based hydrogels in osteoarthritis therapy are considered. Overall, as versatile platform materials, PVA-based hydrogels demonstrate significant potential for clinical translation in cartilage repair.