Highly efficient mRNA transfection with droplet cell squeezing for cellular engineering

We present a novel droplet-based intracellular delivery platform for mRNA transfection. The platform leverages the use of two immiscible fluids to encapsulate a cell and external cargos within a single droplet. The formed droplets travel a narrow z-axis stepwise constriction, smaller than the cell diameter, exerting a physical opening of the cell membrane. Consequently, the platform enables highly effective internalization of cargo into the cell through a combination of diffusive and convective flow. The presented microfluidic approach offers high mRNA transfection efficiency (>98%) with nearly clog-free operation. These results highlight the platform’s potential as a next-generation microfluidics-based intracellular delivery system, showcasing its capacity to achieve both exceptional delivery efficiency and high-throughput capabilities for cell therapy applications.