From Chips-in-Lab to Point-of-Care Live Cell Device: Development of a Microfluidic Device for On-Site Cell Culture and High-Throughput Drug Screening

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.