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.