*2.2.5 Skin substitutes replacing the dermis: treatment of full thickness burns*

The early definitive closure of burn wounds is problematic when the total body surface area exceeds 50% as burn are begins to exceed the available skin donor site area. Dermal substitutes in this setting are used to actively temporise the wound bed until split skin grafting can be performed. Examples of dermal substitutes commonly used in acute burns include:

• Integra

#### • Biodegradable Temporising Matrix (BTM)

The dermal matrix strategy was developed to combat these issues. Pioneered by Burke and Yannis [1, 2], the strategy involved producing a scaffold to allow autologous tissue in growth and establish a neo-dermis. The material developed, Integra, is a cross-linked type 1 collagen scaffold supported by shark chondroitin-6-suplahte glycosaminoglycan. It is physiologically closed with a bonded pseudo-epidermis of silicone. The expense of the product and issues arising from placing non-vascularised biological material on the surface of a wound in an immune compromised patient and anticipating neovascularisation without infection has resulted in variable usability and success in acute burns. The cost of this product often limits its use to very large burn wounds or as a 'patch-up' to cover persistent wounds that remain following primary auto-grafting procedures.

The development of biodegradable polymers and, at the start of this millennium, a completely synthetic, biodegradable polyurethane dermal matrix was designed and developed in Adelaide, Australia, using biodegradable polymer developed in Melbourne, Australia; this is known as the NovoSorb Biodegradable Temporising Matrix (BTM; Polynovo). The synthetic composition means that is not prone to infection by micro-organisms and if it does occur it is localised, not requiring removal or replacement [16]. The loss of skin graft over integrated BTM is uncommon and as also observed with Integra, the appearance of the meshed graft is considerably improved compared to autografting alone. The presence of a 'neo-dermis' provides a bed across which interstitial epithelialisation can occur without needing granulation tissue and so the cosmetic appearance is improved. In fact, the thinner the graft, the better the appearance and the less obvious the mesh pattern. The presence of a 'neo-dermis'

provides a bed across which interstitial epithelialisation can occur without needing granulation tissue and so the cosmetic appearance is improved. In fact, the thinner the graft, the better the appearance and the less obvious the mesh pattern
