To test the system, the team cultured cervical cancer cells in a dish. Then, using electrical fields perpendicular to one another, they were able to zap the nanowires into a pre-set spot and plop them down in a precise location. "In this way, we can predetermine the path that the wires will travel and deliver a molecular payload to a single cell among many, and even to a specific part of the cell," Levchenko said.
During the course of this study, the team also established that the desired effect generated by the nanowire-delivered TNF-alpha was similar to that experienced by a cell in a living organism.
The team members envision many possibilities for this method of subcellular molecule delivery.
"For example, there are many other ways to trigger the release of the molecule from the wires: photo release, chemical release, temperature release. Furthermore, one could attach many molecules to the nanowires at the same time," Levchenko said. He added that the nanowires can be made much smaller, but said that for this study the wires were made large enough to see with optical microscopy.
Ultimately, Levchenko sees the nanowires becoming a useful tool for basic research.
"With these wires, we are trying to mimic the way that cells talk to each other," he said. "They could be a wonderful tool that could be used in fundamental or applied research." Drug delivery applications could be much further off. However,
Levchenko said, "If the wires retain their negative charge, electrical fields could be used to manipulate and maneuver their position in the living tissue."
|Contact: Mary Spiro|
Johns Hopkins University