Transparent photothermal hydrogels for wound visualization and accelerated healing

ABSTRACT Utilizing photothermal hydrogels as a wound dressing is a promising strategy to accelerate wound healing. Usually, a photothermal hydrogel has a strong light-absorbing capability, and hence its transparency can be largely sacrificed, which is unbeneficial for the visual monitoring of wound states. It remains challenging to balance the trade-off between the photothermal conversion and wound visualization for the photothermal hydrogel dressing. Herein, a composite photothermal hydrogel film with high transparency is presented for the visual monitor of the wound, which is constructed by incorporating Cs x WO 3 nanorods into the networks of polyacrylamide hydrogels. The composite photothermal hydrogel film exhibits high light absorption in the near-infrared region and high transmittance in the visible light region. Under 980 nm laser irradiation, the composite hydrogel can be heated up to 45 °C. In vivo animal experiment on mouse skin wound model shows that the composite hydrogel film can locally heat the skin wound to accelerate healing while maintaining more than 70% transparency to realize real-time observation of the wound. This study provides the first attempt to solve the problem of opacity in photothermal hydrogel dressings, promoting the possibility of its clinical applications.