Dynamic control of cell migration using optical tweezers and microfluidic channel

This paper presents the development of a single-cell motility assay method that allows the quantification of cell chemotaxis under complex hydrodynamic condition. The specially designed microparticles, which contain cytokines and chemokines, are trapped by the optical tweezers in motion while releasing the chemical to stimulate the cell polarization and migration. The morphology, localization, and migration speed of the cell are examined quantitatively under different shear stresses. Experiments of migrating leukemia cells led by two microparticles releasing SDF-1a are performed to demonstrate the effectiveness of the proposed approach. This method will provide a new opportunity to probe the mechanism of cell migration at molecular and nano-scale precision level, and help clinicians to develop new targeted therapies in nanomedicine.