Abstract:Phenolic acid composite hydrogels have garnered significant attention in the biomedical field in recent years due to their excellent physicochemical properties and favorable biocompatibility. This study aims to prepare a novel phenolic acid composite hydrogel and systematically evaluate its properties. Gallic acid and malic acid were selected as the primary constituents. The hydrogels were prepared via a self-assembly method，followed by a comprehensive investigation of their microscopic morphology and rheological properties. Swelling ratio，antioxidant activity，thermal stability，and photostability of loaded substances were assessed. Characterization was performed using scanning electron microscopy （SEM） and a rheometer. Results indicated that the incorporation of malic acid reduced the length of the fibrous structures within the three-dimensional network of the hydrogel. The most stable hydrogel structure was achieved at a malic acid concentration of 60 mg/mL. Hydroxyl radical scavenging assays demonstrated that the antioxidant capacity of the phenolic acid composite hydrogel increased with higher malic acid concentrations. Thermal stability tests revealed that the hydrogel maintained satisfactory stability at temperatures up to 60 ℃. Furthermore，measurements of swelling ratio and water retention capacity confirmed the excellent hydration ability of the hydrogels. Drug loading assays showed that the resveratrol loading capacity of the hydrogel increased with rising malic acid concentration. The load loss rate assessments further indicated that the photostability of loaded substances improved as the malic acid content increased.