Hyaluronic acid/polyphenol sunscreens with broad-spectrum UV protection properties from tannic acid and quercetin

Currently, commercial sunscreens cause a number of biotoxicity and environmental issues, making it imperative to develop biocompatible alternatives. In this study, we aimed to develop an alternative sunscreen from two ecofriendly and biocompatible natural polyphenolic compounds, tannic acid (TA) and quercetin (Que). The sunscreen was prepared through a simple process using an oil-in-water emulsion as the medium and hyaluronic acid (HA) as the base polymer to improve biocompatibility. The HA/TA/Que. sunscreen prepared in this study exhibits 0 % transmittance in the UVB region and <15 % transmittance in the UVA region, resulting in excellent sun-protection properties (SPF 30). Remarkably, the as-prepared HA/TA/Que. sunscreen has a suitable viscosity and similar UV protection properties to those of commercial sunscreens. The HA/TA/Que. sunscreen also exhibits 90.4 % antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, demonstrating an ability to effectively capture reactive oxygen species that directly affect the skin. In addition, the cell viability was >90 % at a concentration of 50 μg/mL after 7 days, indicating excellent cytocompatibility. Owing to its various advantageous features, the HA/TA/Que. sunscreen with excellent sun protection properties and multiple functionalities is expected to resolve many environmental and biological issues caused by commercial sunscreens.