Plasma-based non-thermal device induces selective epidermal and follicular epithelial change
Society for Investigative Dermatology (SID) 2016 Annual Meeting, May 11-14, 2016, The Westin Kierland Resort & Spa, Scottsdale, Arizona. Abstract 527:
AE Bennett1, A Rabionet1, R Atkins2, C Prieto-Granada1, M Muthig3, P Rodriguez-Waitkus1, CG Nelson1 and M Jaroszeski2 1 Department of Dermatology & Cutaneous Surgery, University of South Florida College of Medicine, Tampa, FL, 2 Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL and 3 STEM Genesis, Tampa, FL
May 14, 2016: Transfer of energy from a laser to the skin has been used to achieve selective photothermolysis of target structures and for ablation, whereas pulses of direct current electricity have been used for transcutaneous delivery of drugs and genes; pain, heating of, and unintentional damage to non-target tissues can create significant adverse effects. We designed and constructed a novel energy transfer device comprising a Helium-based non-thermal plasma generator and the associated instrumentation to drive it. Effects when applied to murine terminal-hair-bearing skin of female C57BL/6 mice of 6-7 weeks age were evaluated by conventional light microscopic histopathology of punch biopsy specimens. Morphology of the epidermis, dermis, subcutis, and adnexae was characterized for each condition in a blinded manner. Controls revealed expected normal murine skin histopathology, with most hairs being in patches of synchronized telogen as previously described. Applications of an 8-kV, 500-mA negative polarity for 2-3 minutes resulted in selective damage to the surface and follicular epithelium at all levels from the infundibulum to the bulb, including the outer root sheath bulge, characterized by keratinocyte swelling and nuclear vacuolization, with variable degrees of necrosis. Longer treatment times, or use of a positive polarity, resulted in a contiguous band of full-thickness epidermal and partial dermal coagulative necrosis to a variable depth of 0.1 - 0.5 mm. This plasma device is thus capable of delivering non-thermal destructive energy in a controlled manner with selective targeting or ablation based on adjustable settings. The biophysics of these effects and the full range of capabilities are linked objectives requiring further study.