Capture and reagent exchange (CARE) wells for cell isolation, labeling, and characterization

Abstract

Cell therapy is an emerging field that uses cells as living drugs to treat a broad array of acute and chronic diseases. Most cell therapies in clinical trials are made using standard bench methods, whose open processing require manufacturing in expensive GMP cleanrooms. As cell therapies progress, new methods are needed to enable scalable manufacturing while maintaining process integrity, reducing environmental exposure, and limiting critical cell and reagent use. Here, we introduce capture and reagent exchange (CARE) wells that allow critical processing steps to be integrated into a closed microfluidic device. The unique property of CARE wells is that they allow reagent exchange from an attached channel without cell loss from wells. We show through simulation and experiment that this feature is present in cylindrical wells whose depth is sufficient to generate multiple recirculating vortices and is independent of flow rate in the channel. We demonstrate that CARE wells can be used to perform cell separation, on-chip labeling, and characterization of monocytes as the first steps toward a closed microfluidic system for production of dendritic cell therapies. Immunomagnetic separation of CD14 + monocytes from peripheral blood mononuclear cells (PBMCs) into wells was performed with purity of 97 ± 2% and capture efficiency of 50 ± 17%. On-chip labeling, washing, and characterization were performed using two cell surface markers (CD14 and HLA-DR) on over 3000 cells captured in a 5193-well device. The combination of high purity separation and reagent exchange without cell loss with robust performance over wide range of input and operating conditions makes this technique a promising approach for scalable manufacturing and analysis of cell therapies.