365 A human ex vivo burn model – its characterization and use for preclinical testing of innovative wound dressings

Abstract

Numerous processes, including heat shock, inflammatory and tissue regeneration responses are activated upon a burn injury, resulting in a complex pathophysiology affecting the whole organism. Reliable burn models are needed to elucidate the exact sequence of events during the healing process and to evaluate the effects of innovative wound dressings. We analysed contact burns induced on fresh skin explants. Gene expression patterns and cytokine production profiles of key mediators of the local heat shock response, inflammation, and of tissue regeneration were analysed for up to 24 hours after the burn injury. We also used the open flow microperfusion (OFM) technology to analyze mediators released to the interstitial fluid (ISF). Significant alterations in gene expression were found for heat shock, inflammatory and tissue repair responses as soon as one hour after burn injury. In the ISF also significant changes were found for a number of mediators, such as VEGFA. Cooling the injuries using bacterial nanocellulose dressings reduced the thermal damage significantly. This novel ex vivo human skin approach is suitable to study especially the immediate early responses to skin injuries including burns. Gene expression patterns, cytokine profiles, histology and ultrastructural analyses give valuable insights into the mechanisms at the very beginning of the wound healing process. This model can be used to evaluate innovative wound dressings as shown for a bacterial nanocellulose dressing.