Use of a Polylactide-based Copolymer as a Temporary Skin Substitute for a Patient With Moist Desquamation Due to Radiation

Skin reactions are known adverse effects of radiation therapy. Despite advances in skin care products, there is still a demand for optimal skin care products to improve the therapy of these lesions. The authors report the use of a polylactide-based copolymer (Suprathel, PolyMedics Innovations GmbH, Denkendorf, Germany) as a temporary skin substitute for covering the skin defects of a patient with moist desquamation due to radiation.

Skin reactions are known adverse effects of radiation therapy.¹ At an early stage they present as skin erythema, accompanied by local hyperthermia, edema, and irritation. In a further stage they are accompanied by dry desquamation characterized as erythematous, dry, flaky, or peeling skin. A more severe reaction is the moist desquamation, a painful skin peeling with exposure of the dermis and oozing of serum.² It occurs when ionizing radiation destroys the cells of the skin’s basal layer that receives more than 3000 centigray.³ These reactions are not only painful and uncomfortable but also provide a potential focus for infection and can sometimes lead to early cessation of the treatment, which can deteriorate outcomes by reduction of the necessary dose.¹ Although wound healing theory and skin care products have been studied over the past 30 years and various skin care products have been developed, there are still controversies regarding the appropriate care for such skin reactions.^1,4 An optimal wound dressing for the therapy of moist desquamation due to radiation should be simple to use and inexpensive, while being able to reduce pain, improve wound healing, and prevent skin infection. In addition, it would be beneficial for patient comfort if such a dressing could be left in place during radiotherapy.  A variety of dressings have been studied, ranging from a semi-open dressing to an open method or use of protective substances such as cortisone ointments, aqueous lanolin, and gentian violet.¹ However, none of these dressings combine all of the above-mentioned criteria of an optimal wound dressing for moist desquamation. This case report chronicles the authors’ experience with a relatively new polylactide-based temporary skin substitute, Suprathel (PolyMedics Innovations GmbH, Denkendorf, Germany). This material represents a biodegradable, synthetic copolymer for temporary wound coverage that is already widely used in the treatment of burns.

A 66-year-old woman presented with a melanoma in situ in the plantar foot. Because of the large extent of these lesions, a surgical therapy was deemed as too morbid. Therefore, the decision was made to treat her by radiotherapy. A total dose of 40 gray (Gy) over 20 fractions was administered, after which an exacerbation of the radiation skin reactions with the appearance of a moist desquamation appeared (Figure 1). The moist desquamation was debrided, and the polylactide-based temporary skin substitute was applied to the wound (Figure 2). After application of this temporary skin substitute, the patient reported a subjective pain reduction. Therefore, the initiated radiotherapy could be completed in the planned manner with a cumulative dose of 64 Gy. Inspection of the wound dressing on the third day showed good adherence of the polylactide-based temporary skin substitute. After application, it became transparent and a pink and well-perfused wound bed was seen (Figure 3). With an uncomplicated course without infection occurrence, the polylactide-based temporary skin substitute became detached from the wound edges and was detached completely after reepithelization on the tenth day after application (Figure 4). As seen in the figures, the initially erythematous skin around the moist desquamation became paler during the process of healing. 

Despite advances in skin care products, there is still a demand for solutions to improve therapy of radiation skin reactions. Surveys conducted over the past 10 years show practice is inconsistent and controversies about the most appropriate wound management technique still exist.^1,2,4,5 A relatively new polylactide-based temporary skin substitute is known to be beneficial in the therapy of superficial and partial-thickness skin lesions such as burns and skin graft donor sites. Superiority to established dressings was seen in several aspects. A significant reduction of pain in donor sites of split-thickness skin grafts was shown when compared to a paraffin gauze dressing (Jelonet, Smith and Nephew, Mississauga, Ontario, Canada),⁶ a hydrophilized polyurethane wound dressing (Omiderm, Omikron Scientific Ltd, Rehovot, Israel)⁷, and a porous contact layer consisting of a polyamide net coated with a  soft silicon layer (Mepitel, Mölnlycke Health Care, Erkrath-Unterfeldhaus, Germany).⁸ 

The polylactide-based temporary skin substitute releases lactate during the process of degradation. In several studies, lactate was shown to have a positive effect in wound healing due to an increased release of endothelial growth factor from macrophages⁹ and the stimulation of endothelial cell migration.¹⁰ A poly L-lactic acid nanosheet was shown to protect partial-thickness burn wounds in mice against bacterial wound infection after inoculation with Pseudomonas aeruginosa.¹¹ 

Since a moist desquamation occurs when ionizing radiation destroys the cells of the skin’s basal layer, it is comparable to a superficial partial-thickness burn,³ In such lesions, the hair follicles, where most stem cells reside, are not injured. These cells can differentiate into epidermal, follicular, and adnexal structures and can therefore allow spontaneous healing.^12-14 On the basis of this previous experience, the authors used a polylactide-based copolymer as a temporary skin substitute for the first time for the therapy of radiation skin reactions. Since the depths of superficial partial-thickness burns and moist desquamation caused by radiation are comparable and there are scientifically proven benefits of this polylactide-based temporary skin substitute, the authors believed it would also be an adequate wound dressing material for the patient. Furthermore, the skin substitute was successfully used outside of burn surgery in the therapy of toxic epidermal necrolysis,¹⁵ staphylococcal scalded skin syndrome,¹⁶ phototoxic plant burns,¹⁷ and epidermolysis bullosa.¹⁸

There are several advantages to using this polylactide-based temporary skin substitute. Application on the skin is quick and easy, even on indented areas such as fingers or ears, since the material is elastic and has good plasticity. It is acceptable to all religious and ethnic groups, in contrast to Biobrane (Smith and Nephew, St. Petersburg, FL), which consists of porcine collagen and therefore cannot be used by Muslims. The nontoxic, biocompatible, and biodegradable polylactide-based temporary skin substitute enables permanent covering of the radiation-skin lesion until complete healing without the necessity of further wound dressing changes. This enables patients to continue radiotherapy and may therefore increase patient comfort and compliance, possibly leading to better treatment outcomes. With progressing wound healing, the polylactide-based temporary skin substitute is cast off and detaches completely after reepithelization. Due to increasing economic pressures in health care today, costs are an important aspect of any medical treatment. The price in Switzerland of $110 USD (113 CHF) for a 9 cm x 10 cm sheet seems to be high; however, against the background of the reduction of wound dressing changes, the price appears less. In the literature, a financial benefit was even shown using this polylactide-based temporary skin substitute to treat a split-thickness skin graft donor site compared to the use of the paraffin gauze dressing due to lower costs of dressing changes (eg, nursing care and physician care) and additional costs (eg, pain medication and aseptics⁶). However, this report includes only 1 case. It requires a randomized, controlled study to provide proof of this first promising result.

The polylactide-based temporary skin substitute appears to be an appropriate dressing in the therapy of moist desquamation induced by radiotherapy. It is easy to apply, cost effective, reduces pain, optimizes wound healing, and reduces potential skin infections. Finally, it allows the continuation of therapy without delay, which may prove to be a great benefit for future radiotherapeutic treatment outcomes. 

Affiliations: University Clinic of Plastic and Hand Surgery, University Hospital, University of Bern, Inselspital, Switzerland; Department of Plastic, Reconstructive, Hand and Burn Surgery, BG-Trauma Center, Eberhard Karls University Tuebingen, Germany; and University Clinic of Radio-Oncology, University Hospital, University of Bern, Inselspital, Switzerland

Correspondence:
Jens Rothenberger, MD
University Clinic of Plastic and Hand Surgery
University Hospital, University of Bern
Inselspital, Switzerland
jens.rothenberger@gmail.com

Disclosure: Departmental funding was used to perform this case report. The authors have no financial or other conflicts of interest.