A novel technique for transferring large and small molecules into cells has been developed. The technique, named cell volume exchange for convective transfer, or cell VECT, uses compression to squeeze small volumes of cytosol from cells which is rapidly replaced with the molecule of interest—a plasmid, polysaccharide, or nanoparticle. The paper describing the technique has been published in Materials Today.
The technique leverages cells’ ability to lose and rapidly gain back their cytosol within milliseconds. They flow quickly through a microfluidic device and encounter “speed bumps” that squeeze out small amounts of cytosol. The cells naturally refill their insides bringing in the macromolecule or target gene of interest.
"Our technique doesn't depend at all on the properties of macromolecules to do the work," explained Anna Liu, Ph.D and author of the paper. "The activity is all caused by the convective influx of fluid volume back into the cells. The molecules in the fluid are just along for the ride, which allows us to transfer molecules without regard to their size or properties."
The research team tested the technique on a wide range of cell types from prostate cancer cells to primary lymphocytes. A variety of molecules were successfully delivered into the cells include polysaccharide, dextran, proteins, RNA, plasmids, and 100 nanometer particles. The technique enables researchers to transfer large macromolecules into cells which has been challenging. Overcoming this hurdle could have positive implications on cell engineering and cell-based therapies.
"Cell VECT means we are no longer limited by the size of the cargo that a virus can carry," said Alexander Alexeev, an associate professor in the Woodruff School of Mechanical Engineering and a collaborator on the research. "This may open a new way for researchers to engineer living cells using more complex molecules. Cargo size would no longer be a critical issue."
The team plans to continue their research to better understand the cell VECT process and monitor cells over a longer period of time to make sure that viability is not impacted.