Application of engineered dermal templates has transformed burns treatment. Commercial dermal substitutes such as Integra®, Pelnac® and NovoSorb BTM are designed to act as templates for the development of neo-dermis while sealing wounds temporarily. They provide a niche for host cell infiltration and templates for neo-vascularisation. Subsequently, the seal can be removed and the wound closed by definitive split skin grafting. In addition to temporally sealing the wound and reducing the risk of infection, dermal substitutes may prevent wound contraction and, therefore, reduce fibroblast to myofibroblast conversion and scarring. The physical (porosity, stiffness, roughness, and degradation rate) and biochemical (receptor binding sites, toxicity, and growth factors retention) properties of the dermal template are some of the factors that would ultimately define success of the graft.
In this animal study we compared collagen based dermal substitutes with and without GAG, namely Integra and Pelnac respectively to a fully synthetic material, NovoSorb BTM, in terms of wound contraction, vascularisation, host cell infiltration, localised growth factors concentrations and ECM deposition. We showed that wounds treated with Pelnac showed significantly higher contraction compared to others. BTM was significantly more vascularised than others (p < 0.05). CD31 positive endothelial cells invaded BTM graft from both the edge and subcutaneous layer, whereas the invasion was mostly from the edges of the wound in Integra and Pelnac grafts. Real-time PCR also showed differences between growth factor expression and ECM deposition of invading fibroblasts. Overall, the study highlights novel behavioural differences between dermal substitutes, which should be considered at the time of their clinical application.