Abstract
Research on keloid is limited by the lack of proper in vitro and animal model reflecting in vivo status. Based on heterogeneity of keloid and important role of endothelial cells in its pathogenesis, a novel 3D in vitro keloid spheroid prepared with keloid fibroblasts and endothelial cells was evaluated in this study. Commercial cell lines of keloid fibroblasts and endothelial cells were used at various cellular ratios to generate keloid spheroids to determine the optimal condition. Keloid spheroids from three keloid patients were also made and their usefulness as in vitro models, including their responses to drugs, were assessed. Spheroids with higher endothelial cell proportions exhibited increased viability and propagation ability. Patient-derived keloid spheroids showed heterogeneity which might reflect individual clinical conditions. The optimal ratio of fibroblasts to endothelial cells was determined to be 4:1 for keloid spheroids based on gene expression and viability analyses. Patient-derived keloid spheroid showed better keloidal changes in genetic expressions than 2D monolayer culture. Spheroids exhibited varied responses and resistance to each drug used for keloids, depending on the cell type used. 3D keloid spheroids might provide an effective in vitro model for investigating disease pathogenesis and appropriate treatment modalities for future precision medicine.