Preparation and evaluation of gastrodin microsphere-loaded Gastrodia elata polysaccharides composite hydrogel on UVB-induced skin damage in vitro and in vivo

Skin damage from sun exposure is a common issue among outdoor workers and is primarily caused by ultraviolet rays. Upon absorption of these rays, the skin will experience inflammation and cell apoptosis. This study explored the concept of 'Combination of medicine and adjuvant' by utilizing Gastrodia elata polysaccharide, a key component of Gastrodia elata Bl.‌, to develop a new hydrogel material. Oxidized Gastrodia elata polysaccharide (OGEP) and carboxymethyl chitosan (CMCS) was use to prepare a biocompatible, biodegradable and self-healing hydrogel OGEP/CMCS (OC). And this hydrogel was further loaded with Gastrodin-containing microspheres (GAS/GEL) to create GAS/GEL/OGEP/CMCS (GGOC) hydrogel. Characterization studies revealed that OC and GGOC hydrogels exhibited favorable mechanical properties, antioxidant activity and biocompatibility. The experiments showed that OC and GGOC hydrogels could regulate mitochondrial membrane potential, prevent mitochondrial breakage, inhibit proinflammatory factors, prevent NF-κB protein activation and regulate apoptosis-related pathways. This study highlighted the application potential of Gastrodia elata polysaccharide as a 'Combination of medicine and adjuvant' and the anti-UVB damage effect of the prepared hydrogel.