Physiological effects of ultrasound mist on fibroblasts

Chronic wounds present an increasing challenge in healthcare and consume a substantial portion of healthcare cost. Although new treatments have been developed, treatment success has not been improved greatly. Ultrasound has long been employed in medicine. Its unique ability to deliver energy makes it an ideal candidate as a wound care modality. We proposed that ultrasound would differentially affect intracellular signaling pathways and, with the ability to assess this effect using a noncontact form of ultrasound, were provided with a means to test this proposal.

The cellular morphology, mitogenic activities, expression of keratinocyte growth factor (KGF) and transforming growth factor beta-1 (TGF-beta1), and activation of extracellular regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways of dermal fibroblasts were studied after ultrasound treatment. Untreated and scrape-wounded fibroblasts were utilized as controls.

There was no difference in morphology observed, except for vacuolization in ultrasound-treated fibroblasts. Mitogenic activities were similar between ultrasound-treated and scrape-wounded fibroblasts. Ultrasound-treated fibroblasts exhibited a much earlier increase in KGF expression, ERK activation, and JNK activation. The ERK/JNK ratio was increased markedly in ultrasound-treated fibroblasts.

We conclude that ultrasound induces cellular responses that may be beneficial to wound healing.