Bio-Engineered Skin Grafts/Substitutes
Bioengineered skin grafts or substitutes (also known as tissue-engineered skin substitutes, artificial skin, living skin equivalents, human skin equivalents, or skin alternatives) are used when the patient has a limited amount of skin to use for grafts or are too ill to endure the creation of further wound sites. They are most commonly used to treat chronic wounds, severe burns, and rare skin conditions such as recessive dystrophic epidermolysis bullosa. They are also a potential alternative to skin grafting for patients suffering from conditions such as acute surgical wounds, diabetic foot ulcers, leg ulcers, and lower extremity ulcers.
Bioengineered skin may be composed of a dermal (inner) layer, an epidermal (outer) layer, or a combination of both, which is embedded into a cellular or acellular matrix (a support structure). Acellular matrices do not contain living cells, but are rather composed of materials such as collagen, hyaluronic acid, and fibronectin. Cellular matrixes contain living cells obtained from humans (patient or other individual) or another species.
Bioengineered skin can be created using the following substances:
- Human tissue (autologous): Derived from the patient’s own cells
- Human tissue (allogeneic): Derived from a human other than the individual themselves. A common practice is to utilize cells derived from neonatal foreskin (skin obtained from newborn babies during circumcision)
- Non-human tissue (xenographic): Derived from non-human organisms such as cows, pigs, and horses
- Synthetic materials: A laboratory-produced product derived from man-made materials such as collagen, polymers, and silicone
- Composite: Derived from any mixture of materials listed above
Bioengineered skin can serve as either temporary or permanent wound coverings. It promotes new skin growth and stimulates wound healing by introducing living cells that are able to re-establish a moist wound environment and structural support. Bioengineered skin grafts are easily available, affordable, and biodegradable. They may also reduce treatment costs and the length of hospital stays.
There are various manufacturers that produce bioengineered skin substitutes. It is important to recognize the difference between each product, as well as the fact that each requires the approval of the US Food and Drug Administration (FDA) for specific indications.