Fabrication and Property Investigation of Anisotropic PVA/HA Hydrogels for Tissue Repair

In the field of wound healing and tissue repair, hydrogel dressings have attracted significant interest as functional materials due to their excellent water retention, favorable biocompatibility, and controllable drug release capabilities. In this study, anisotropic poly(vinyl alcohol) (PVA)/hyaluronic acid (HA) hydrogels were fabricated using a directional freezing method. By adjusting the mass ratio of PVA to HA, the influence of the ordered network structures and compositions on the hydrogel properties was systematically investigated. The microstructure, hydration behavior, and mechanical properties were characterized using scanning electron microscopy (SEM), rotational rheometry, and UV-Vis spectrophotometry. Furthermore, small-molecule Rhodamine B (RhB), macromolecular bovine serum albumin (BSA-FITC), and proanthocyanidins (PC) were selected as model drugs. Using full-immersion and Transwell-based unidirectional release systems, the effects of microstructure and composition on drug loading and release kinetics were evaluated. Furthermore, the results of CCK-8 assay and intracellular ROS detection indicated that the hydrogel system exhibited good cytocompatibility, and that the PC-loaded anisotropic hydrogel could effectively alleviate H₂O₂-induced oxidative stress. In summary, based on the study of the structure-activity relationship of PVA/HA hydrogels, the rules governing how the gel composition and network structure regulate its performance in wound dressing applications were elucidated, providing experimental evidence and theoretical support for the design of functional wound dressings.