Abstract
Optically-induced electroporation (OIE) is a promising microfluidic-based approach for cell electroporation. However, previously proposed microfluidic cell electroporation devices required tedious sample pre-treatment steps, including media exchange. To facilitate this OIE process for user-friendly cell electroporation, we present herein a new design for continuous OIE on a microfluidic device that is capable of replacing culture media and electroporation buffers in a seamless fashion. The on-chip integration of media exchange with OIE avoided critical issues such as cell loss and damage, both of which are common with traditional, centrifuge-based approaches. Our new system is therefore suitable for handling small or rare cell populations. Medium exchange modules of a micropost array railing structure and a deterministic lateral displacement structure were first explored and integrated with the OIE module respectively. The efficacy of the integrated systems was demonstrated by transfection of a green fluorescent protein (EGFP) plasmid into human embryonic kidney 293T cells with an efficiency of 8.3%. It was the highest efficiency reported so far for the existing OIE systems on microfluidic system. Also, successful co-transfections of three distinct plasmids (EGFP, DsRed, and ECFP) into the cells were demonstrated, suggesting the system is capable of performing multiple gene transfections in to mammalian cells.