Fractional Skin Harvesting: Autologous Skin Grafting without Donor-site Morbidity

Background: Conventional autologous skin grafts are associated with significant donor-site morbidity. This study was conducted to determine feasibility, safety, and efficacy of a new strategy for skin grafting based on harvesting small columns of full-thickness skin with minimal donor-site morbidity. Methods: The swine model was used for this study. Hundreds of full-thickness columns of skin tissue (~700 µm diameter) were harvested using a custom-made harvesting device, and then applied directly to excisional skin wounds. Healing in donor and graft sites was evaluated over 3 months by digital photographic measurement of wound size and blinded, computer-aided evaluation of histological features and compared with control wounds that healed by secondary intention or with conventional split-thickness skin grafts (STSG). Results: After harvesting hundreds of skin columns, the donor sites healed rapidly without scarring. These sites reepithelialized within days and were grossly and histologically indistinguishable from normal skin within 7 weeks. By contrast, STSG donor sites required 2 weeks for reepithelialization and retained scar-like characteristics in epidermal and dermal architecture throughout the experiment. Wounds grafted with skin columns resulted in accelerated reepithelialization compared with ungrafted wounds while avoiding the “fish-net” patterning caused by STSG. Conclusion: Full-thickness columns of skin can be harvested in large quantities with negligible long-term donor-site morbidity, and these columns can be applied directly to skin wounds to enhance wound healing

Fractional CO2 Laser-Assisted Drug Delivery

Background and Objectives: Ablative fractional resurfacing (AFR) creates vertical channels that might assist the delivery of topically applied drugs into skin. the purpose of this study was to evaluate drug delivery by CO2 laser AFR using methyl 5-aminolevulinate (MAL), a porphyrin precursor, as a test drug.Materials and Methods: Two Yorkshire swine were treated with single-hole CO2 laser AFR and subsequent topical application of MAL (Metvix(R), Photocure ASA, Oslo, Not-way), placebo cream and no drug. MAL-induced porphyrin fluorescence was measured by fluorescence microscopy at skin depths down to 1,800 mu m. AFR was performed with a 10.6 mu m wavelength Prototype CO2 laser, using stacked single pulses of 3 millisecond and 91.6 mJ pet, pulse.Results: AFR created cone-shaped channels of approximately 300 mu m diameter and 1,850 mu m depth that were Surrounded by a 70 mu m thin layer of thermally coagulated dermis. There was no porphyrin fluorescence in placebo cream or untreated skin sites. AFR followed by MAL application enhanced drug delivery with significantly higher porphyrin fluorescence of hair follicles (P < 0.0011) and dermis (P < 0.0433) versus MAL alone at skin depths of 120, 500, 1,000, 1,500, and 1,800 pro. AFR before MAL application also enhanced skin surface (epidermal) porphyrin fluorescence. Radial diffusion of MAL from the laser-created channels into surrounding dermis was evidenced by uniform porphyrin fluorescence up to 1,500 mu m from the holes (1,000, 1,800 mu m depths). Skin massage after MAL application did not affect MAL-induced porphyrin fluorescence after AFR.Conclusions: Ablative fractional laser treatment facilitates delivery of topical MAL deeply into the skin. for the conditions of this study, laser channels approximately 3 mm apart followed by MAL application could produce porphyrins throughout essentially the entire skin. AFR appears to be a clinically practical means for enhancing uptake of MAL, a photodynamic therapy drug, and presumably many other topical skin medications. Lasers Surg. Med. 42:113-122, 2010. (C) 2009Wiley-Liss, Inc.Harvard Univ, Sch Med, Massachusetts Gen Hosp, Wellman Ctr Photomed, Boston, MA 02114 USAUniv Copenhagen, Dept Dermatol, Bispebjerg Hosp, DK-2400 Copenhagen, DenmarkUniversidade Federal de São Paulo, Dept Dermatol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Dermatol, Escola Paulista Med, BR-04023900 São Paulo, BrazilWeb of Scienc

First-Intention Incisional Wound Healing in Dogs and Cats: A Controlled Trial of Dermapliq and Manuka Honey

This study aimed to compare incisional wound healing in cats and dogs after the topical application of Μanuka honey and a new medical device, Dermapliq. Comparisons were made between each treatment and control, between the two treatments, and between dogs and cats. Twelve cats and twelve dogs were included in this study, and the impact of the two substances was examined through cosmetic, clinical, ultrasonographical, and histological evaluation. The use of Dermapliq in first-intention wound healing achieved a significantly better cosmetic evaluation score and better total clinical score at days 20–41, compared to the control, in both dogs and cats. The ultrasonographically estimated wound area was smaller with Dermapliq compared to the control. Wounds treated with Dermapliq showed histologically less inflammation compared to the control. The use of Manuka honey did not show a significantly better cosmetic score compared to the control. Skin thickening was significantly higher after using Manuka honey compared to the control and so was the total clinical score. However, the median wound area, as was evaluated ultrasonographically, was significantly smaller when wounds were treated with Manuka honey, the difference being more apparent in dogs. Dermapliq was proven to be a better choice in achieving favorable wound healing than Manuka honey in dogs and cats in first-intention healing. In our study, cats had a statistically better cosmetic score and less skin thickening and scar width compared to dogs. Histologically, cats showed significantly less edema, higher inflammation and angiogenesis scores, and lower fibroblast and epidermis thickening scores when compared to dogs