Pro-NP™ protect against TiO2 nanoparticle-induced phototoxicity in zebrafish model: exploring potential application for skin care.

Titanium dioxide nanoparticles (TiONPs) are used in sunscreen products to protect the skin from the sun's ultraviolet rays. However, following exposure to sunlight, the photocatalytic activity of TiONPs can produce an excess of reactive oxygen species (ROS), causing skin cell damage, triggering an inflammatory response. In zebrafish model, we evaluated how well Pro-NP™ (biodegradable NPs containing superoxide dismutase and catalase) could protect them from TiONP-induced photo-oxidative stress. We hypothesized that the antioxidant properties of Pro-NP™ would protect zebrafish embryos from the phototoxic effects of TiONPs, improving overall survival and growth. Dechorionated embryos were treated with TiONPs alone or co-treated with Pro-NP™, and then exposed to simulated sunlight. Pro-NP™ by itself caused no toxicity; however, for embryos exposed to 100 μg/ml TiONPs, zebrafish survival was reduced to ∼40% and at 500 μg/ml to ∼10%. In contrast, at 100 μg/ml TiONP, co-treatment with Pro-NP™ increased zebrafish survival in a dose-dependent manner. Co-treatment also improved percent of embryos hatching and resulted in normal growth of zebrafish. On the other hand, embryos treated with TiONPs alone developed deformities, had reduced pigmentation, and showed severely truncated growth. Pro-NP™ afforded a greater level of protection against TiONP-induced phototoxicity than other antioxidants (vitamin E or N-acetylcysteine) commonly used in topical skin care formulations. We conclude that Pro-NP™ exert significant protective effects against TiONP-induced phototoxicity and could be developed as a safe, effective skin care product, used alone or in combination with sunscreen products to protect the skin from sun's UV radiation.