Cell type separation and cytometry via cell rolling can be used for a variety of purposes including disease diagnosis, biological research, and therapeutics. Situations that require the separation of heterogenous cell populations run the gamut from medical practices such as blood cell counting to therapeutic procedures such as the isolation of pure stem cells and isolation and quality control of T-cells for immunotherapies.
Current cell separation strategies, including FACS, affinity columns, magnetic bead based separation, and rosette separation, involve expensive equipment or multiple processing steps that are expensive and time consuming. They also often involve cell modifications that could potentially change the characteristics of the original cell. Despite the laborious nature of these methods, they are still quite often not specific enough. Ideally, a new separation tool would facilitate rapid, accurate separation of cells into multiple populations while requiring minimal cell handling.
This invention takes advantage of receptor-ligand interaction between surface-immobilized affinity molecules (such as selectins or other molecules) and the surface of cells that results in cell rolling. Rolling is exhibited by cells such as leukocytes, hematopoietic stem cells, metastatic cancer cells, and platelets. These cells transiently adhere to surfaces coated with selectin and travel along them with more ease than along uncoated surfaces. Cells directed along a particular flow trajectory on the selectin-coated surface will deviate slightly from their original direction when they reach the edge of the selectin-coated surface, so as to remain on the higher-affinity selectin coating. The angle of deviation depends on the interaction between the cells and selectin, which varies broadly among different cell types. By pattering a variety of angles of selectin bands along a rolling surface, cells can be sorted based on their rolling properties into different wells. The sorted cells can be used immediately without further processing. This manner of separation affords not only the separation of rolling from non-rolling cells, but also the separation of different subpopulations of rolling cells. Furthermore, the continuous-flow separation design is easy to implement and scale for parallel operation. For instance, the separation flow chambers may be linked in series to a common cell inlet and buffer inlet, as well as channels of outlets for sorted cells, to increase throughput. In addition, the outlet channels may have volumetric designs to quantify the amount of successfully sorted cells.
Quick separation of cell subpopulations
Easy implementation and scaling
Minimum cell handling
No pre- or post-sort cell modifications or processing necessary