173 3D <i>In Vitro</i> Model of Human Burn Wound: A Platform for Evaluating Macrophage Response and Angiogenesis in Surgical Treatment

Abstract Burns impose significant physical, psychological, and economic burdens on millions worldwide. According to the World Health Organization (WHO), an estimated 180,000 deaths occur annually due to burns. Research on burn recovery has largely relied on animal models due to their ability to replicate the complex microenvironment of skin injuries in controlled settings. These models offer insights into tissue regeneration and allow for the evaluation of novel treatment approaches, including the use of small extracellular vesicles (exosomes) derived from stem cells. The objective of this study was to develop a 3D in vitro burn model using decellularised porcine skin scaffolds seeded with human dermal fibroblasts (HDFs) and keratinocytes (HaCaT cells). Controlled burn wounds (8 x 2 mm) were inflicted on the skin models using a preheated flat metal wire, and the models were cultured in an air-liquid interface to mimic the wound-healing environment. To simulate inflammatory responses, macrophages were incorporated into the model, and angiogenesis was evaluated using the chorioallantoic membrane assay (CAM). Furthermore, exosomes derived from adipose-derived stem cells (ADSCs) were applied topically to assess their impact on wound healing. Histological analysis and cytokine measurements of IL-6 and IL-10 were conducted to assess re-epithelialisation, inflammation, and overall wound healing. This 3D model provides a valuable platform for studying burn wound pathogenesis, assessing treatment efficacy, and exploring the therapeutic potential of exosomes in a controlled setting.