Controllable and Stable Fusion Strategy on Microfluidics
Authors: Yaqi Bai, Xiaoling Zhang, Xuefeng Wang, Mengli Xu, Jun Yang, and Ning Hu
Abstract
This paper presents a microfluidic device with 200 cell “cage” structures. Based on this microfluidics device, a new simple and stable electrofusion method was developed. Under hydrodynamic force, the cells moved to the desired “cage” cell capture structure and efficiently formed cell pairs (∼80.0 ± 4.6%). Intimate intercellular connectivity was induced by the precise modulation of hypotonic solution substitution and the microstructure, which ensured no cell movement or displacement during the cell electroporation/electrofusion process. It also guaranteed repeated electroporation occurring in the same contact region and provided a stable cell membrane recombination and a cell fusion microenvironment. When the pulse signal was applied, a high fusion efficiency of ∼88.3 ± 0.6% was demonstrated on the microfluidic device.
Fig 1. Cell electrofusion device illustration. (A) A schematic image of microelectrode and PDMS mold used for the fabrication of the chip and an image of the PDMS microfluidic chip. (B) SEM image of the microchip; scale bar, 50 μm, (C) Scheme for cell capture, pairing,
solution substitution and electrofusion. The cells were subsequently introduced into the device, and a hypotonic buffer was added to swell the cells until they were in close contact. Next, a pulse voltage was applied to induce cell fusion. (D) Principle of the cells captured in the trap array. (E) Parameters of the chip.
Fig 2. Osmotic pressure analysis. (A) Flow field simulation with no cell capture, one cell captured, and two cells captured in the capture chamber. (B) Solution substitution at flow rates of 0.2 μL/min, 0.5 μL/min, 0.8 μL/min. (C) Substitution of the original position solution
under different osmotic pressures. (D) Shear forces along the x direction of the cell membrane during the process of solution substitution. Dashed lines represent cells on the left, and the solid lines represent cells on the right. (E) Diameter of cells under different
osmotic pressures. Scale bars: 20 μm.
Selected Figures
Keywords: Chemical structure; deformation; microstructures; osmotic pressure; plasma membrane; electroporation; cell capture; microfluidics; iFlow controller
Anal. Chem. 2024