title: Thermal Response of In Vivo Human 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.
authors.affiliation: Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Woraphong
authors.initials: W
authors.lastname: Manuskiatti
authors.affiliation: Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Penvadee
authors.initials: P
authors.lastname: Pattanaprichakul
authors.affiliation: Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Siriluk
authors.initials: S
authors.lastname: Inthasotti
authors.affiliation: Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Panitta
authors.initials: P
authors.lastname: Sitthinamsuwan
authors.affiliation: Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Suchanan
authors.initials: S
authors.lastname: Hanamornroongruang
authors.affiliation: Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Rungsima
authors.initials: R
authors.lastname: Wanitphakdeedecha
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Sorawuth
authors.initials: S
authors.lastname: Chu-Ongsakol
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D004548:Elasticity; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology; D008543:Melanins / Q000378:metabolism; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism; D009339:Needles; D011846:Radio Waves / Q000009:adverse effects; D012867:Skin / Q000528:radiation effects*; D013696:Temperature
chemical_list: D008543:Melanins; D009077:Mucins; D003094:Collagen