Easy Squeezy Transfection

Intracellular delivery techniques are used to deliver proteins, mRNA, plasmid DNA, and other cargos into cells and are central to a variety of gene- and cell-based therapies. Viral transduction and physical transfection methods such as electroporation are most commonly used, but are often compromised by poor delivery efficiencies and limited throughput. Mechanoporation via viscoelastic squeezing offers a promising alternative, leveraging physical forces to generate pores in the cell membrane through which cargos can enter, and eliminating the need for external energy inputs, which cause cell damage and decrease cell viability.

In their recent publication, Rashin Mohammadi and colleagues present a high-throughput microfluidic platform that leverages viscoelastic squeezing to deliver biomolecules into target cells while maintaining high cell viability. Here, a sample stream containing target cells and cargo molecules is surrounded by a viscoelastic sheath fluid within a microfluidic channel. By adjusting the flow rates of the sample and sheath fluids, a "virtual channel" is formed in which cells can be deformed and their membranes permeabilized, enabling cargo to enter target cells. Real-time adjustment of these flow rates allows precise control over cell deformation, making the technique adaptable to various cell types. The platform was used to successfully deliver a broad range of cargos, including mRNA, plasmid DNA, and ribonucleoprotein complexes, into cells that are known to be difficult to transfect. In addition, the method enables high-throughput transfection of between 10 and 20 million cells per minute, far exceeding typical microfluidic transfection rates by an order of magnitude. High transfection efficiencies, high cell viabilities, and operational flexibility position this technology as a useful tool for therapeutics, including genome editing, CAR-T cell therapy, and stem cell engineering.

Written by Kate Petersen

Read the published article here.