Fig. 9. Skin substitutes.

Skin substitutes have undergone development over the past decade from temporary materials used to induce wound healing towards permanent tissue-engineered materials that offer definitive healing. This figures reflects a summary of some promising skin substitutes or treatments to induce wound regeneration. a | The common principle of skin substitutes is to the deliver proteins, growth factors and/or cells via a delivery vehicle or matrix that will then be integrated into the wound and form new autologous skin. b | ReCell is not a composite skin substitute, but a device that sprays a cell suspension of skin cells including epithelial cells, fibroblasts melanocytes and other resident cells onto the wound or grafted area to improve healing and scarring. c | The skin gun (RenovaCare) delivers autologous cells and/or stem cells to wounds to improve wound healing. Although this is a promising approach, no clinical trials or substantial evidence have been reported that indicate that the skin gun will enter the clinical arena. d | Recently, a hand-held device has been designed that can print 3D autologous skin²⁴⁸. This device is based on microfluidic technology and can deliver cells specifically and accurately in an ‘ink’, which serves as a matrix. e | A skin substitute using autologous cells from a healthy donor and a matrix shows self-assembly of dermal and epidermal structures. Although the ideal tissue-engineered skin derivative has not been described, this technology will change the way burn care is delivered and will improve acute and long-term outcomes. Image in part b courtesy of Avita Medical. Image in part c courtesy of RenovaCare Inc. Part d provided by A. Guenther (University of Toronto, Canada), and adapted with permission from ref.²⁴⁸, Royal Society of Chemistry. Panel e is reprinted from ref.²⁶⁷, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).