‘Nanochannel electroporation’ allows precise gene therapy without needle
MedWire News: Researchers have developed a technique - nanochannel electroporation (NEP) - that allows small amounts of DNA known as transfection agents to be inserted into cells using electric pulses.
Bulk electroporation (BEP) and, more recently, microfluidics-based electroporation (MEP), are widely used for transfecting cells as they are fast and simple techniques that have few limits regarding cell size and type.
However, precise dose control of the transfecting agent to the cell has not been demonstrated with either technique.
"NEP allows us to investigate how drugs and other biomolecules affect cell biology and genetic pathways at a level not achievable by any existing techniques," said study author James Lee, from Ohio State University in Columbus, USA, in a press statement.
Writing in the journal Nature Nanotechnology, the team explains that the newly developed device consists of two microchannels that are connected by a nanochannel.
Optical tweezers are used to place the cell to be transfected in one microchannel, with the transfection agent positioned in the second microchannel. A voltage pulse between the microchannels creates an intense electric field over a small part of the cell surface membrane enabling a small, precise amount of transfection agent to be driven through the nanochannel and cell wall into the cytoplasm.
"After the pulse, any additional, diffusively driven transfection is limited by the small conductance of the nanochannel," explain Lee et al.
Importantly, this technique does not affect cell viability, say the researchers, who add that dose control is achieved by adjusting the length and number of pulses used.
"Whereas BEP and MEP create large numbers of small pores over a significant fraction of a cell surface, NEP appears to create either a single very large pore or several large pores in the cell membrane adjacent to the nanochannel," write the authors.
However, "in NEP, because the affected area of the cell membrane is very limited (less than 1% of even a small-area MEP device), none of our experiments resulted in cell death," they add.
"We hope that NEP could eventually become a tool for early cancer detection and treatment - for instance, inserting precise amounts of genes or proteins into stem cells or immune cells to guide their differentiation and changes - without the safety concerns caused by overdosing, and then placing the cells back in the body for cell-based therapy," Lee concluded.
By Helen Albert