Highly bioactive triple-helical nano collagens for accelerated treatment of photodamaged skin.

Skin damage caused by excessive UV exposure has gradually become one of the most common skin diseases, leading to desquamation, scab formation, inflammation and even skin cancer. Animal-derived hydrolyzed collagen peptides have been developed to treat UV-damaged skin; however, they have raised severe concerns such as potential viral transmission, random sequences and the lack of a triple helix structure. Nano collagen, a novel type of short collagen, has attracted increasing attention in the mimicking of natural collagen, while its applications in UV-damaged skin treatment remains unexplored. Herein, we have created a series of nano collagens and for the first time studied their capability of accelerating UV-damaged skin healing. Nano collagens, consisting of repetitive (GPO)n triplets and a GFOGER motif, display a stable triple-helical structure, significantly promoting fibroblast adhesion, proliferation, and migration. The repair effects of nano collagens have been investigated using an acute UV-damaged skin mouse model. Combo evaluations indicate that nano collagens contribute to recovering the dermis density and erythema index of UV-damaged skin. Histological analysis further demonstrates their capability of promoting the healing of damaged skin by accelerating re-epithelialization and collagen regeneration. These highly bioactive triple-helical nano collagens present a novel strategy for the treatment of UV-damaged skin, providing promising applications in cosmetics and dermatology.