Licochalcone A-loaded elastic liposomes/silk fibroin composite hydrogel: A dual-functional transdermal platform for enhanced anti-photoaging efficacy

Photoaging is predominantly driven by ultraviolet (UV) radiation, a key factor in extrinsic skin aging. Licochalcone A (LA), a natural flavonoid with antioxidant and anti-inflammatory properties, offers a promising alternative to conventional retinoid-based therapies due to its lower irritation potential. However, the poor skin penetration of LA limits its anti-photoaging application. To overcome this limitation and provide complementary photoprotection, a composite hydrogel with both reparative and photoprotective functions (LA-EL-gel) was developed by physically crosslinking UV-absorbing silk fibroin with LA-loaded elastic liposomes (LA-EL). These liposomes were co-modified with isopropyl myristate (IPM) and polyoxyethylene castor oil (PCO) to enhance the skin penetration of LA. In vitro and in vivo studies confirmed that LA-EL-gel possesses UVB absorption capability, enhances skin retention and penetration of LA, and effectively alleviates UVB-induced photoaging by inhibiting oxidative stress and promoting collagen production. Moreover, LA-EL-gel showed no toxicity to the liver and kidneys in mice and effectively mitigated UVB-induced weight loss and skin moisture reduction. In conclusion, LA-EL-gel is a promising transdermal delivery system with anti-photoaging efficacy and favorable biosafety, thereby offering a new strategy and experimental basis for developing an efficient, low-toxicity, and multifunctional anti-photoaging therapeutic platform. Download: Download high-res image (377KB) Download: Download full-size image