Living skin equivalents constructed using human amnions as a matrix

Background: Living skin equivalents (LSEs) are being used to treat burn wounds, skin defects, and chronic wounds, and today, several biomaterials are applied as dermal matrices in LSEs. The amnionic membrane (AM) is known to have useful properties as a dermal matrix and can be used to construct a LSE. Objective: To develop a new LSE with human AM as the matrix. Methods: Human AM was de-epithelialized and investigated to determine whether it supported keratinocyte adherence and proliferation, and fibroblast in-growth and proliferation. A new LSE was constructed by seeding keratinocytes on the epithelial side of fibroblast-populated, de-epithelialized AM and was investigated histologically. The LSE was transplanted onto a full-thickness wound on a nude mouse and a histological examination was conducted. Results: De-epithelialized AM supported the adherence and proliferation of keratinocytes and the ingrowth of fibroblasts. The new LSE demonstrated good mechanical properties and revealed good morphology, with a well differentiated epidermis and well developed basement membrane. The LSE grafts survived well on nude mice, showing good morphology. Conclusion: A LSE with amnions as a matrix exhibited good morphology, low cost, and good mechanical properties and may be useful as a skin substitute for clinical use. (C) 2009 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.