Functional nanocomposite PVA hydrogels for tissue engineering: Mechanisms and applications

Polyvinyl alcohol (PVA) hydrogels have attracted extensive interest in tissue engineering due to their excellent biocompatibility, hydrophilicity, and tunable physicochemical properties. However, pristine PVA hydrogels often suffer from limited mechanical strength, biological activity, and functional performance, restricting their application in complex tissue regeneration. To address these limitations, various nanomaterials have been incorporated into PVA matrices to construct multifunctional nanocomposite hydrogels with enhanced properties. This review systematically summarizes recent advances in nanocomposite PVA hydrogels for tissue engineering, covering diverse nanomaterial systems and fabrication strategies, and further focuses on the underlying mechanisms of nanomaterial reinforcement. Particular emphasis is placed on nanoparticle dispersion behavior, interfacial interactions, and network structural regulation, as well as their effects on mechanical properties, electrical conductivity, physicochemical characteristics, and biological functions. In addition, corresponding tissue repair outcomes across different tissue applications are discussed. Despite promising preclinical potential, this class of materials still faces significant challenges in long-term biosafety, degradation behavior, fabrication reproducibility, and clinical translation. Through a comparative analysis between clinically approved PVA-based materials and emerging nanocomposite PVA hydrogel systems, this review identifies key barriers to clinical translation and highlights future directions for the development of safe, multifunctional nanocomposite PVA hydrogels with clinical translational potential.