Applications and mechanisms of therapeutic ultrasound in skin repair and regeneration

Ultrasound modulates cellular and tissue processes underlying skin repair and regeneration via thermal and mechanical effects, including cavitation, and can act as an external trigger to facilitate transdermal delivery or activate ultrasound-responsive materials. This review summarizes the acoustic fundamentals and Mechanotransduction pathways of different types of ultrasounds, as well as research advances in wound healing, pathological scar intervention, skin tissue remodeling, skin appendage regeneration, and synergistic applications with ultrasound-responsive materials. Emphasis is placed on the molecular and cellular mechanisms by which ultrasound regulates inflammatory responses, angiogenesis, re-epithelialization, and extracellular matrix remodeling. Currently, apart from studies on focused ultrasound and ultrasound-assisted wound therapy, most supporting evidence is derived from in vitro experiments, animal models, or small-sample clinical studies. Inconsistent acoustic parameters and outcome measures, as well as insufficient long-term safety data, represent major barriers to its clinical translation.