From Chips-in-Lab to Point-of-Care Live Cell Device: Development of a Microfluidic Device for On-Site Cell Culture...

Live cell assays provide real-time data of cellular responses. In combination with microfluidics, applications such as automated and high-throughput drug screening on live cells can be accomplished in small devices. However, their application in point-of-care testing (POCT) is limited by the requirement for bulky equipment to maintain optimal cell culture conditions. In this study, we propose a POCT device that allows on-site cell culture and high-throughput drug screening on live cells. We first observe that cell viabilities are substantially affected by liquid evaporation within the microfluidic device, which is intrinsic to the polydimethylsiloxane (PDMS) material due to its hydrophobic nature and nanopatterned surface. The unwanted PDMS-liquid-air interface in the cell culture environment can be eliminated by maintaining a persistent humidity of 95-100% or submerging the whole microfluidic device under water. Our results demonstrate that in the POCT device equipped with a water tank, both primary cells and cell lines can be maintained for up to 1 week without the need for external cell culture equipment. Moreover, this device is powered by a standard alkali battery and can automatically screen over 5000 combinatorial drug conditions for regulating neural stem cell differentiation. By monitoring dynamic variations in fluorescent markers, we determine the optimal doses of platelet-derived growth factor and epidermal growth factor to suppress proinflammatory S100A9-induced neuronal toxicities. Overall, this study presents an opportunity to transform lab-on-a-chip technology from a laboratory-based approach to actual point-of-care devices capable of performing complex experimental procedures on-site and offers significant advancements in the fields of personalized medicine and rapid clinical diagnostics.