Rapid, label‐free enrichment of lymphocytes in a closed system using a flow‐through microfluidic device.

The majority of adoptive cellular therapies are produced from peripheral mononuclear cells obtained via leukapheresis and further enriched for the cells of interest (e.g., T cells). Here, we present a first‐of‐its‐kind closed system, which effectively removes ~85% of monocytes and ~88% of platelets, while recovering ~88% of concentrated T cells in a separate output stream, as the leukapheresis sample flows through a microfluidic device at 5 mL/min. The system is driven by a common peristaltic pump, enabled by a novel pressure wave dampener, and operates in a closed bag‐to‐bag configuration, without requiring any specialized, dedicated equipment. When compared to standard density gradient centrifugation on paired samples, the new system demonstrated a 1.5‐fold increase in T cell recovery and a 2‐fold reduction in inter‐sample variability for this separation outcome. The T cell‐to‐monocyte ratio of the leukapheresis sample was increased to 20:1, whereas with density gradient processing it decreased to 2:1. As a result of superior purity and/or gentler processing, T cells enriched by the system showed a 2.7‐times higher fold expansion during subsequent culture, and an overall 3.5‐times higher cumulative yield. This centrifugation‐free and label‐free closed system for enriching lymphocytes could significantly simplify and standardize the manufacturing of life‐saving cellular therapies. [ABSTRACT FROM AUTHOR]