Preparation of thymol-loaded Pickering emulsion gel film and its application in wound healing

At present, the treatment of diabetic wounds is challenging and time-consuming. In this study, a delivery system combining thymol-loaded Pickering emulsion and gel film has been investigated to accelerate wound healing. The nanoparticles (SPI-CMC) composed of soy protein isolate (SPI) and carboxymethyl cellulose (CMC) were used to stabilize Pickering emulsion and loaded into polyvinyl alcohol (PVA)-porous starch (PS)-hyaluronic acid (HA) gel membrane (PPH) matrix. The PPH matrix was loaded with thymol (PPH+T), which effectively solves the problem of solubility and compatibility of thymol. Moreover, the PPH+T matrix based on Pickering emulsion and gel membrane achieving the antibacterial, anti-inflammatory, angiogenesis and tissue collagen formation effect. The composite gel membrane exhibited a long-term sustained release of thymol for up to 48   h, and had good antibacterial activity against Escherichia coli ( E.coli ) and Staphylococcus aureus ( S.aureus ). The antibacterial diameters of the two were 19.73   ± 1.375 mm and 21.94   ± 0.486 mm, respectively. It was verified in animal experiments that the healing of normal wounds and diabetic wounds was accelerated, and the final healing rates were 97% and 94%, respectively. Therefore, the composite gel membrane prepared in this study has great potential in wound antibacterial and healing, and provides a basis for effective treatment of chronic wounds.