Evaluation of the therapeutic efficacy of human skin equivalents manufactured through droplet-based bioprinting/nebulization technology

BackgroundIn the field of dermatology, many studies have been conducted on artificial skin to develop alternative animal testing methods for therapeutic agents for skin sensitization or skin regeneration. Recent advances in 3D bioprinting have reached a stage where skin equivalents can be produced more easily and accurately than by handmade methods. While most of the previously reported skin equivalents (SKE) were manufactured by extrusion-based bioprinting, we fabricated SKE using a different approach through low-viscosity droplet-based bioprinting/nebulization technology.ObjectiveFabrication and application of hSKE as a novel 3D bioprinting method.MethodBased on the evidence that the constructed droplet-based bioprinting has high-viability cell deposition, the dermis was first formed through the output of collagen-bioink and human dermal fibroblast-bioink. Next, human SKE were generated by constructing mature epidermis through the output of human epidermal keratinocyte-bioink and air-liquid culture.ResultsThe prepared SKE showed epidermis and dermis structures that were morphologically similar to the native skin of human and mouse. Furthermore, the treatment effects were compared after transplanting the printed only collagen and SKE into a mice wound healing model. As a result, it was confirmed that skin regeneration was promoted through improvement of collagen deposition and vascularization in the wound area rather than only collagen when SKE was transplanted.ConclusionsOverall, based on global trends, through the production of simple and systematic SKE based on 3D bioprinting, we suggest the possibility of further improvement in the field of alternative animal testing methods or skin regeneration treatments.