Methacrylated hyaluronic acid/laponite photosensitive, sustained-release hydrogel loaded with bilobalide for enhancing random flap survival through mitigation of endoplasmic reticulum stress.

Random flaps are extensively utilized in plastic surgery due to their flexibility compared to traditional axial vascular system arrangements and their resemblance to injured skin in color, thickness, and texture. Despite these advantages, they are susceptible to ischemia-reperfusion injuries and subsequent necrosis post-transplantation. Bilobalide (BB), a sesquiterpene compound derived from Ginkgo biloba, exhibits notable antioxidant and anti-inflammatory properties and is commonly used to treat ischemiareperfusion injuries. However, its short half-life restricts its sustained efficacy in random flaps. In this study, we synthesized a multi-crosslinked, photosensitive methacryloyl hyaluronic acid(HAMA)/laponite(Lap)/bilobalide (BB) hydrogel. This dualcrosslinked hydrogel demonstrates superior mechanical properties and biocompatibility while providing a stable release of bilobalide. In vitro experiments showed that it significantly reduces edema, promotes angiogenesis, and enhances the survival of random flaps. Further network pharmacology analysis and recovery experiments suggested that the hydrogel's beneficial effects are mediated by the regulation of endoplasmic reticulum stress and specifically identified the regulation of the PERK/TXNIP/NLRP3 signaling pathway as crucial to its anti-inflammatory effects. Therefore, this HAMA/Lap/BB hydrogel promotes the survival of random flaps in rats by alleviating endoplasmic reticulum stress, providing a novel intervention strategy for the treatment of random flaps injuries.