Encapsulation of green tea polyphenol nanospheres in PVA/alginate hydrogel for promoting wound healing of diabetic rats by regulating PI3K/AKT pathway

Difficult healing of skin wounds is one of the serious complications of diabetes mellitus. Green tea polyphenols (TP) have been found to have good therapeutic effects on wounds healing. However, TP that is soluble in water and easily been oxidized requires a gel material that provides moisture retention, oxidation prevention, and sustained release of TP to achieve better wound healing effect. Therefore, in this work, novel tea polyphenol nanospheres (TPN) were synthesized and encapsulated in a PVA /alginate hydrogel (TPN@H). The prepared TPN@H was characterized and applicated in model diabetic rats for promoting wound healing and regulating immune response. Fourier-transform infrared spectroscopy (FT-IR), UV spectroscopy, scanning electron microscopy (SEM), atomic force microscope (AFM), confocal laser scanning microscopy (CLSM), dynamic light scattering (DLS) and differential scanning calorimetry (DSC) were used for characterization. Animal experiments and molecular mechanism research proved that TPN@H could promote wound healing of diabetic rats by regulating PI3K/AKT signaling pathway.