Somatic and stem cell pairing and fusion using a microfluidic array device

There is considerable excitement about the prospect of tissue repair and renewal through cell replacement therapies. Nonetheless, many of these techniques may require the reprogramming of somatic and stem cells through cell fusion. Previous fusion methods often suffer from random cell contacts, poor fusion yields, or complexity of design. We have developed a simplified cell-electrofusion chip that possesses a dense microelectrode array, which enables the simultaneous pairing and electrofusion of thousands of cells by manipulation dielectrophoretic force and electroporation. Human embryonic kidney 293 (HEK293) cells, mouse fibroblasts (NIH3T3 cells), and mouse embryonic stem cells were arranged for cell fusion with the same and mixed cell type. The pairing efficiency for a 2-cell alignment of mixed cells was ~35%, and a fusion efficiency of ~46% in cell pairs was achieved. Significant cell death occurs with fusion voltages ≥ 10 V, and electrofusion with our chip was achieved on a ~1000 V cm−1 electric field strength induced by a low intensity voltages (9 V). Therefore, the chip used in this study provides a simple, low voltage alternative with sufficient throughput for hybrid cell experiments and somatic cell reprogramming research.