Separation of mononuclear cells from progenitor products by a novel inertial microfluidic method

Mononuclear cells (MNCs), a type of leukocyte, require enrichment owing to their rarity for research and clinical applications. The enrichment of MNCs is generally performed via conventional methods (e.g., density gradient centrifugation). However, these methods have downsides, such as being labor intensive, energy and time consuming, and requiring advanced equipment. Therefore, inertial microfluidics has recently drawn widespread attention as a way to overcome these limitations. This work aims to investigate MNC separation using a novel spiral inertial microfluidic system design. After MNCs were enriched by Ficoll stratification, the cells were separated according to their size and deformability properties by passing through the microfluidic system. In the final step, various cell markers were examined for characterization in these cells collected at outlets. In this paper, we determined that MNCs obtained from three different hematological products could be sorted with a recovery rate of 97.5% and a purity level of 84%, whereas red blood cells (RBCs) had a depletion ratio of 80% using Sunflower-designed microfluidic system. The loss of MNCs in this system was much lower than that in density gradient centrifugation. The separation technique studied here has several advantages, such as continuous processing, a high operation flow rate (e.g., 0.7 ml/min), simplifying the operative procedures for automation, and creating no clogging problems. Additionally, this technique can be easily integrated with downstream applications, such as direct analysis of MNCs via a flow cytometer, and can reduce the number of man-hand manipulation processes.