Thermal Response ofIn VivoHuman Skin to Fractional Radiofrequency Microneedle Device

Abstract

Background. Fractional radiofrequency microneedle system (FRMS) is a novel fractional skin resurfacing system. Data on thermal response to this fractional resurfacing technique is limited. Objectives. To investigate histologic response of in vivo human skin to varying energy settings and pulse stacking of a FRMS in dark-skinned subjects. Methods. Two female volunteers who were scheduled for abdominoplasty received treatment with a FRMS with varying energy settings at 6 time periods including 3 months, 1 month, 1 week, 3 days, 1 day, and the time immediately before abdominoplasty. Biopsy specimens were analyzed using hematoxylin and eosin (H&E), Verhoeff-Van Gieson (VVG), colloidal iron, and Fontana-Masson stain. Immunohistochemical study was performed by using Heat Shock Protein 70 (HSP70) antibody and collagen III monoclonal antibody. Results. The average depth of radiofrequency thermal zone (RFTZ) ranged from 100 to 300 μm, correlating with energy levels. Columns of cell necrosis and collagen denaturation followed by inflammatory response were initially demonstrated, with subsequent increasing of mucin at 1 and 3 months after treatment. Immunohistochemical study showed positive stain with HSP70. Conclusion. A single treatment with a FRMS using appropriate energy setting induces neocollagenesis. This wound healing response may serve as a mean to improve the appearance of photodamaged skin and atrophic scars.

Aging skin and non-surgical procedures: a basic science overview

“…Energy-and laser-based therapies such as radiofrequency microneedling, fractional non-ablative laser and fractional ablative laser, all induce broad destruction of tissue, including the destruction of cells containing oxidatively damaged DNA and proteins. While the level of oxidative damage post-treatment has not been specifically tested, these treatments are shown to induce the expression of specific heat shock proteins known to promote the clearance of damaged proteins [61][62][63] .…”

When Wounds Are Good for You: The Regenerative Capacity of Fractional Resurfacing and Potential Utility in Chronic Wound Prevention

“…2,45 At day 7, HSP47 and HSP70 are expressed inside the treatment zone as well as more diffusely throughout the dermis. 45 NAFL and fractional radiofrequency microneedling have both been reported to induce HSP70 expression, 46,47 which is severely attenuated in diabetic skin, 48 with an expression time course that correlates with delayed healing. 49 Long-term upregulation of HSPs has been reported after large-area ablative laser resurfacing.…”

Minimally Invasive Cosmetic Procedures in Ethnic Skin: A Review

“…Melanin is not a target of FRFM devices and thus people of color can successfully be treated in general [49]. Manuskiatti et al [50] found histologic evidence of neocollagenesis with a single FRFM session in 2 darker skinned women at minimal energy level of 50 Watts; though there was also histologic evidence of hyperpigmentation at their highest energy setting of 80 watts [48]. Two studies on FRFM in Asian patients with acne scars FST III-V demonstrate improvement in scarring based on blinded investigator assessment with transient adverse effects including erythema and edema [51,52].…”