Sunscreen Formula of FeO(OH)·H(2)O/TiO(2) With Spectral Selectivity to Enhance Collagen Biosynthesis via Fibroblast Test.

OBJECTIVE: To develop a sunscreen formula with spectral selectivity that filters harmful light (280-550 nm) while allowing beneficial light (550-760 nm) to permeate and thus to boost collagen generation. METHODS: A variety of sunscreen filters and their combinations were tested for transmittance spectrum. The spectral selectivity was quantified by Selection Index (SI), and the optimal formula was identified. Then, human dermal fibroblasts (HDFs) were subjected to simulated sunlight exposure with the application of this formula. The cell viability and collagen levels were measured post-exposure. RESULTS: The combination of TiO(2) and FeO(OH)·H(2)O displays spectral selectivity and reaches the optimal SI value at the mixing ratio of 64:36. This mixture, when formulated with traditional UV filters, significantly elevates the level of Collagen I. CONCLUSION: This work uncovers the influence of spectral selectivity on the enhancement of sunscreen performance and proposes a filter combination with spectral selectivity. This formula, when integrated with conventional UV sunscreens, allows for the beneficial effects of sunlight to be more pronounced. This discovery may provide fresh insights for the design of future sunscreen products.