Tissue-Engineered Products Provide New Options for Skin Coverage

Several types of tissue-engineered skin substitutes offer plastic surgeons new alternatives for skin coverage in patients with burns and other types of difficult-to-treat wounds, according to a special topic article in the December issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

"Skin substitutes have been a great advance for plastic surgery and provide several advances and options to heal wounds," write Dr. Dennis P. Orgill of Brigham and Women's Hospital, Boston, and colleagues. Their review introduces six categories of currently available tissue-engineered skin substitutes, while highlighting the need for more evidence on the appropriate use in specific situations.

New Options for Difficult Skin Coverage Problems

Providing adequate skin coverage for certain types of wounds—for example, major burns or non-healing skin ulcers—can be a major challenge in plastic and reconstructive surgery. Skin grafts can be used, but in some situations adequate skin donor tissue is simply not available.

Over the years, various tissue-engineered products have enabled new approaches to skin coverage in these difficult situations. "Better understanding of the skin architecture and its bioactive components has enabled the development of a wide range of skin substitutes," Dr. Orgill and coauthors write.

In their article, they provide plastic surgeons with an overview of the range of modern tissue-engineered skin substitutes. The options are categorized as:

Allografts. Products made of processed skin from human donor skin, which can be packaged for a long shelf-life. For example, one allograft product consists of decellularized skin, preserving the underlying structure and bioactive components to help stimulate wound healing.

Allogeneic skin equivalents. Artificially grown skin substitutes used to support regeneration of the patient's own tissues. These one- or two-layer products provide "living and functional cellular skin constructs" to help restore normal wound healing in chronic wounds.

Dermal templates. Semi-synthetic products are made of collagen—the major structural protein of the body's connective tissue. They provide a scaffold for ingrowth of normal cells, which repopulate and eventually replace the scaffold.

Epidermal replacement. "Epidermal equivalent" products cultured or expanded from the patient's own skin cells. These products are limited by their high cost and long culture time (three to four weeks), as well as the fragility of the resulting skin substitute.

Xenografts.Skin from other species processed for use as a skin substitute. For example, sterilized products prepared from pig skin are sometimes used for temporary wound coverage.

"Skin substitutes have been a great advance for plastic surgery and provide several advances and options to heal wounds," Dr. Orgill and coauthors write. They emphasize the need for further research evidence to help guide the most appropriate use of the various types of tissue-engineered skin products.

Dr. Orgill and colleagues also look forward to continued research and development leading to even more advanced skin substitutes for large or nonhealing wounds. They conclude, "Future developments including advances in scaffolds, stem cells, and tissue processing are likely to produce even more clinical options for our patients."

Plastic and Reconstructive Surgery® is published by Wolters Kluwer.