De novo production of human extracellular matrix supports increased throughput and cellular complexity in 3D skin equivalent model

Three-dimensional (3D) tissue models of human skin are being developed to better understand disease phenotypes and to screen new drugs for potential therapies. Several factors will increase the value of these in vitro 3D skin tissues for these purposes. These include the need for human-derived extracellular matrix (ECM), higher throughput tissue formats, and greater cellular complexity. Here, we present an approach for the fabrication of 3D skin-like tissues as a platform that addresses these three considerations. We demonstrate that human adult and neonatal fibroblasts deposit an endogenous ECM de novo that serves as an effective stroma for full epithelial tissue development and differentiation. We have miniaturized these tissues to a 24-well format to adapt them for eventual higher throughput drug screening. We have shown that monocytes from the peripheral blood can be incorporated into this model as macrophages to increase tissue complexity. This humanized skin-like tissue decreases dependency on animal-derived ECM while increasing cellular complexity that can enable screening inflammatory responses in tissue models of human skin.