Design and fabrication of demountable 3D microphysiological systems for modeling barrier function and underlying tissue interactions

Several recent advances in microphysiological systems (MPSs) or organ-on-chip technology have demonstrated its potential for replacing traditional in vitro and animal models in the coming years. Despite the physiological relevance and cost-effectiveness of organ chips, there are several hurdles that must be overcome for widespread adoption for biological studies. Many shortcomings of manufacturing and scalability have been overcome by a transition from PDMS to thermoplastics. However, challenges have arisen in these sealed, brittle systems related to end-point tissue analyses, harvest, and high-resolution imaging, which is particularly difficult for multi-layer organ chips. Here, we present low-cost organ chips that are fluidically sealed but demountable, fabricated using a cut-and-assemble method without the need for cleanroom technologies. We have validated the capabilities of this method by demonstrating the culture of human aortic smooth muscle cells and induced pluripotent stem cell-derived neural cells, encapsulated in gelatin methacryloyl (GelMA) hydrogel on chip, for up to 27 days. The 3D culture layer of the organ chip was removed, and high-resolution images were obtained via immunostaining. Furthermore, these organ chips facilitate rapid redesign and manufacture for alternative tissue and/or interface systems. To our knowledge, this is the first innervated organ chip with multiple removable cell culture layers, as well as the first humanized nerve-artery model that includes a three-dimensional hydrogel culture. In future work, these unique features of our platform can be utilized for investigating the crosstalk mechanisms between different cell types in co-culture. Impact StatementWe present here a new method for fabricating low-cost demountable organ-on-a-chip platforms. This method leverages our recent cut & assemble method for layered 3D organ chips comprised of gas impermeable thermoplastics.