Preparation of Green Tea Polyphenol-Loaded Diacylglycerol Nanostructured Lipid Carrier Hydrogels and Their Activities Related to Skin Protection

Diacylglycerol (DAG) is a functional oil but is rarely used in the cosmetic industry because low solubility, susceptibility to leakage and low viscosity to skin are still the main hurdles. A novel diacylglycerol nanostructured lipid carrier hydrogel (GTP-DAG-NLC-GEL) loaded with green tea polyphenol (GTP) was designed and successfully prepared to broaden DAG's application in cosmetics, which significantly improved GTP stability and skin stickiness of DAG. The results showed that DAG-NLC-GEL had good viscosity, which was 980 Pa·s when the shear rate was 5 rpm, and its viscosity decreased quickly with the increase in shear rate, making it easily expand on skin. Meanwhile, the encapsulation rate and drug loading of GTP in GDP-DAG-NLC-GEL reached 86.7% and 2.6%, respectively, and the DPPH free radicals scavenging rate and inhibition rate of the advanced glycation end-products (AGEs) were 85.46% and 89.72%, respectively, which indicate that GTP-DAG-NLC-GEL has significant skin sunscreen, antioxidant and anti-glycation activities. The GTP-loaded nanostructured lipid carrier hydrogel can be deemed to have great prospects for skin protection in cosmetics.