Electropermeabilization of Mammalian Cells Visualized with Fluorescent Semiconductor Nanocrystals (Quantum Dots)

Abstract

AbstractElectroporation/electropermeabilization is a non-viral technique for gene transfection and drug delivery. Here, the transfer mechanisms were studied with fluorescent nanocrystals (quantum dots, QDs) in mammalian cells. Interactions of the cell membrane and nanoscale particles were visualized after electric pulse treatment. Responses of human multiple myeloma cells to nanocrystals were tracked for periods up to 7 days. Large particles do not cross the membrane directly after pulsing, even if the membrane is permeabilized to small molecules. Large QDs were trapped on the cell membrane for hours after electroporation and were gradually either excluded or internalized by cells. QD uptake efficiency depended on both particle size and membrane transport activity. These results, consistent with an electropermeabilization model, suggest that enhancing the interactions between the cell membrane and macromolecules may improve the transfer efficiency.