A nanometer-scale probe designed to slip into a cell wall and fuse with it could offer researchers a portal for extended eavesdropping on the inner electrical activity of individual cells.
Everything from signals generated as cells communicate with each other to "digestive rumblings" as cells react to medication could be monitored for up to a week, say Stanford engineers.
Current methods of probing a cell are so destructive they usually only allow a few hours of observation before the cell dies. The researchers are the first to implant an inorganic device into a cell wall without damaging it.
The key design feature of the probe is that it mimics natural gateways in the cell membrane, said Nick Melosh, an assistant professor of materials science and engineering in whose lab the research was done. With modification, the probe might serve as a conduit for inserting medication into a cell's heavily defended interior, he said. It might also provide an improved method of attaching neural prosthetics, such as artificial arms that are controlled by pectoral muscles, or deep brain implants used for treating depression.
The 600-nanometer-long, metal-coated silicon probe has integrated so smoothly into membranes in the laboratory, the researchers have christened it the "stealth" probe.
"The probes fuse into the membranes spontaneously and form good, strong junctions there," Melosh said. The attachment is so strong, he said, "We cannot pull them out. The membrane will just keep deforming rather than let go of the probes."
Melosh and Benjamin Almquist, a graduate student in materials science and engineering, are coauthors of a paper describing the research published March 30 in Proceedings of the National Academy of Sciences. The paper is available online.
Up to now, poking a hole in a cell membrane has largely relied on brute force, Melosh said.
"We can basically rip holes in the cells us
|Contact: Louis Bergeron|