Topical recombinant human type III collagen for atopic dermatitis: Evaluation of efficacy and safety.

Recombinant human type III collagen (rhCol III) is a non-animal-derived, biomimetic protein with notable regenerative potential. Nevertheless, its therapeutic efficacy in chronic inflammatory skin conditions such as atopic dermatitis (AD) remains insufficiently explored. This study aimed to evaluate the efficacy and safety of rhCol III as a topical therapeutic agent for AD. Utilizing an ovalbumin (OVA)-induced murine model of AD, topical application of rhCol III substantially ameliorated skin lesions, reduced scratching behavior and epidermal thickening, and suppressed mast cell infiltration and Th2 cytokines (IL-4, IL-13, and TSLP), while also demonstrating a decreasing trend in serum IgE levels. In vitro assays demonstrated that rhCol III inhibited the expression of IL-6, IL-1β, CXCL17 and CXCL22 in TNF-α and IFN-γ-stimulated HaCaT cells, confirming its anti-inflammatory properties. Long-term safety assessments revealed no structural abnormalities in the skin or major organs and no clinically relevant alterations in hematological parameters, bone mineral content (BMC), fat mass, or lean mass following 120 days of continuous topical application in mice. Preliminary clinical observations in infant patients with AD indicated that rhCol III was well tolerated, with observable symptom improvement, particularly in mild-to-moderate cases where topical rhCol III alone produced discernible therapeutic benefits. Collectively, these findings support the therapeutic potential and safety of rhCol III as a novel non-steroidal treatment strategy for AD.