The impact of near-infrared-triggered photothermal therapy on collagen organization and wound healing

Abstract

Soft tissue wounds result in the loss of essential functions, including sensation and barrier protection. Mild photothermal therapy (PTT) has emerged as a promising therapeutic strategy for promoting wound healing and tissue regeneration, primarily through its ability to precisely regulate tissue temperature and thereby influence cellular proliferation and differentiation. In this study, gold nanorods (AuNRs) were employed as photosensitizers and co-cultured with fibroblasts to evaluate the effects of mild PTT on collagen organization and wound healing under the irradiation of 808 nm near-infrared (NIR) laser. AuNRs-mediated photothermal stimulation raised the temperature of the culture medium from 18.0 °C to 37.8 °C within 7 min. This controlled thermal stimulation significantly enhanced fibroblast proliferation and led to a more random distribution of collagen fibers. Moreover, AuNR-mediated mild PTT promoted the differentiation of fibroblast into myofibroblasts and reduced scar tissue formation. These findings highlight the therapeutic potential of mild PTT in soft tissue regeneration by modulating fibroblast behavior and remodeling collagen architecture.