Electrokinetic Manipulation of Biological Cells towards Biotechnology Applications.

The presented study demonstrates the capability of the template-based electrokinetic assembly (TEA) and guidance to manipulate and capture individual biological cells within a microfluidic platform. Specifically, dielectrophoretic (DEP) focusing of K-562 cells towards lithographically-defined "wells" on the microelectrodes and positioning singles cells withing these "wells" was demonstrated. K-562 lymphoblast cells, are widely used in immunology research. The DEP guidance, particularly involving positive DEP (pDEP), enables the controlled guidance and positioning of conductive and dielectric particles, including biological cells, opening new directions for the accurate and efficient microassembly of biological entities, which is crucial for single cell analysis and other applications in biotechnology. The investigation explores the use of glassy carbon and gold as electrode materials. It was established previously that undiluted physiological buffer is unsuitable for inducing positive DEP (pDEP); therefore, the change of media into a lower ionic concentration is necessary. After pDEP was observed, the cells are resubmerged in the Iscove's modified Dulbecco's medium (IMEM), a cell culturing media, and incubated. A dead/alive staining assay was performed on the cells to determine their survival in the diluted buffer for the period required to capture them. The staining assay confirmed the cells' survival after being immersed in the diluted biological buffer necessary for electrokinetic handling. The results indicate the promise of the proposed electrokinetic bio-sorting technology for applications in tissue engineering, lab-on-a-chip devices, and organ-on-a-chip models, as well as contributing to the advancement of single cell analysis.