Applicability and Safety of in Vitro Skin Expansion Using a Skin Bioreactor: A Clinical Trial

Abstract

BackgroundTissue expansion is an effective and valuable technique for the reconstruction of large skin lesions and scars. This study aimed to evaluate the applicability and safety of a newly designed skin expanding bioreactor system for maximizing the graft area and minimizing the donor site area.MethodsA computer-controlled biaxial skin bioreactor system was used to expand skin in two directions while the culture media was changed daily. The aim was to achieve an expansion speed that enabled the skin to reach twice its original area in two weeks or less. Skin expansion and subsequent grafting were performed for 10 patients, and each patient was followed for 6 months postoperatively for clinical evaluation. Scar evaluation was performed through visual assessment and by using photos.ResultsThe average skin expansion rate was 10.54%±6.25%; take rate, 88.89%±11.39%; and contraction rate, 4.2%±2.28% after 6 months. Evaluation of the donor and recipient sites by medical specialists resulted in an average score of 3.5 (out of a potential maximum of 5) at 3 months, and 3.9 at 6 months. The average score for patient satisfaction of the donor site was 6.2 (out of a potential maximum of 10), and an average score of 5.2 was noted for the recipient site. Histological examination performed before and after the skin expansion revealed an increase in porosity of the dermal layer.ConclusionsThis study confirmed the safety and applicability of the in vitro skin bioreactor, and further studies are needed to develop methods for increasing the skin expansion rate.

In vitro skin expansion: Wound healing assessment

“…The human clinical trial evaluated graft viability only through postimplantation take rate; postimplantation, grafts were only evaluated morphologically. Their expansion process was strain based (5% area per day), but it appeared that most grafts were not expanded beyond a couple of days.…”

“…Partial graft take rate was assessed during wound healing. Histology showed no difference in morphology after expansion …”

Serial Tissue Expansion at the Same Site in Pediatric Patients: Is the Subsequent Expansion Faster?

“…Dermal collagen deposition increases and collagen fibers realign along the tension line. Jeong et al [ 7 ] performed a histological examination of before and after skin expansion, demonstrating an increase in the porosity of the dermal layer and an uniaxial arrangement of the collagen fibers. Fragmentation of the elastic fiber and flattening of the dermal papillae also occur in response to tissue expansion [ 8 ].…”

Current and Future Perspectives on Skin Tissue Engineering: Key Features of Biomedical Research, Translational Assessment, and Clinical Application

“…Early work by Atala and co‐workers used bioreactor systems for the expansion of living skin matrices to increase the surface area of skin available for reconstructive purposes, while simultaneously demonstrating that the mechanical properties of native skin were not adversely affected using this method . Following trials showed similar success in patient‐derived skin samples, promising a path for clinical applications . Interestingly, upon a 5 d stimulation of cultured skin constructs (epidermal keratinocytes and dermal fibroblasts on porous silicone sheets) via stretching, Tokuyama et al observed that the constructs exhibited a thicker epidermal layer and higher expression of ECM proteins compared to nonstimulated controls.…”