Label-free microfluidic stem cell isolation technologies

Stem cell research has great potential in clinical applications and regenerative medicine, which highlight the need for efficient stem cell isolation technologies. Enrichment of stem cells is challenging because of its sensitivity to the surrounding environment and its overlapping features with non-target cells. Current gold-standard isolation techniques depend on surface antigens that are exclusively expressed on stem cells, where surface immuno-labeling is followed by flow cytometry or magnetic sorting procedures. It is well-established that stem cells should be enriched with minimal alteration, therefore, isolation without immunological tagging in a label-free format is of great interest. Microfluidic technologies have demonstrated high level of control to precisely manipulate stem cells. Here, we review the recent emerging label-free microfluidic based cell isolation technologies that provide unbiased stem cell enrichment based on their size and deformability, adhesion, and electrical characteristics, and discuss their potential to achieve effective stem cell isolation for research and clinical applications.