Investigation of HepG2 cells' local extrusion induced electric property variation via nanorobotic manipulation system

Human hepatoma cell line HepG2 has been widely utilized in biological field benefits from its unique characteristic of high degree of morphological and functional differentiation. Previously, researchers mainly concentrated on physical isolation of membrane patches of HepG2 cells, almost no research has been reported about the relationship between local extrusion and electric property without physical isolation of membrane patches, although this work is meaningful for improve patch-clamp techniques. Herein, we propose a nanorobotic manipulation system to investigate the relationship between HepG2 cell's local extrusion and its electric property variation. Firstly, a system with three degree-of-freedoms (DOFs) nanorobotic manipulator and 3-DOFs sample stage integrated inside optical microscope (OM) are introduced. Secondly, the experimental procedure, the control strategy and the electric property measurement principle of HepG2 cells are explained in details. Finally, the electric property variation is adopted while the HepG2 is deformed via patch pipette penetration. The results shows that the electric property decreases with the deep of the patch pipette penetration, which has great influence in improving patch-clamp techniques for higher property resolution and lesser invasive manner.