Abstract

In recent years, advances in tissue engineering have brought forward the accessibility of human skin equivalents for in vitro applications; however, the availability of human-based engineered tissue models suitable for high-throughput screening of biologics remains limited. Here, we report a method of manufacturing fully autologous (with both fibroblasts and keratinocytes from the same donor) human skin equivalents for determining preclinical therapeutic antibody adverse immune reactions in vitro. Using a combination of precise solenoid microvalve-based bioprinting and 96-well scale Alvetex inserts, autologous skin cells were bioprinted and cultured to develop a scalable approach to manufacturing skin equivalents. We demonstrated that fibroblasts and keratinocytes can be bioprinted with a high degree of precision while maintaining viability post printing. Histological staining showed that the bioprinted 96-well based skin equivalents were comparable to human skin. The fully autologous human skin equivalents were co-cultured in vitro with autologous peripheral blood monocytes with and without muromonab-CD3 (OKT3) and natalizumab (Tysabri), biologics which are known to cause and inhibit adverse immune reactions (type IV hypersensitivity), respectively. Analysis of supernatants from skin-equivalent monocyte co-cultures revealed significant proinflammatory cytokine responses (such as interferon gamma) in co-cultures treated with OKT3 when compared to Tysabri and negative controls. Consequently, this study provides proof of concept that through a combination of bioprinting and Alvetex scaffold-based culture systems, scalable human skin equivalents can be manufactured for high-throughput identification of adverse immune reactions during preclinical stages of the drug development process.