Nano-pulse Stimulation Shows Early Preclinical Promise
NPS with electrodes is under investigation as a potential new ablative — and possibly immunotherapeutic — cancer treatment modality.
Conceptually, electroporation seems relatively straight-forward. Electrodes deliver very brief (microsecond- or nanosecond-long) electric pulses that render cell membranes more permeable — a process also known as electropermeabilization.
Electroporation is already used in research labs; CRISPR transfection is one protocol for gene editing, for example, moving CRISPR's molecular machinery into target cells.
But the effects of electroporation on tumor cells and their microenvironments are surprisingly complex, researchers are finding.
Microsecond pulse electroporation's effects are largely limited to the cellular plasma membrane. It can be used to deliver therapeutic payloads into cells in a similar way to the electroporation protocol for CRISPR transfection. Electroporation has, for example, been used experimentally in combination with chemotherapy drugs like cisplatin.1,2
But faster, nanosecond-pulsed electric field (nsPEF) electroporation — also called nano-pulse stimulation (NPS) — affects cells beyond the cellular membrane.1,3 NPS was pioneered in the late 1990s by Karl Schoenbach, PhD, and colleagues at Old Dominion University in Norfolk, Virginia.
NPS has been proposed as a potential “drug free” and “purely electrical” cancer treatment modality.1,3 Cell line studies suggest that some tumor types might be more susceptible to NPS than normal human cells, but these findings have not been widely replicated.4,5 Dr Guo noted, further, that in vitro experiments might not reflect how tissues or tumors will respond to NPS.
“In contrast to conventional local cancer therapies, surgery, or radiation therapy, NPS ablation is a non-thermal, drug-free, and radiation-free physical therapy that has been demonstrated to treat cancer [in animal models] in a fast and minimally invasive manner,” said Siqi Guo, MD, of the Frank Reidy Center for Bioelectrics at Old Dominion.