A team of researchers affiliated with Johns Hopkins University Institute for NanoBioTechnology used precise electrical fields as “tweezers” to guide and place gold nanowires (metallic cylinders a few hundred nanometers or smaller in diameter) on predetermined spots, each on a single cell.

Molecules coating the surfaces of the nanowires then triggered a biochemical cascade of actions only in the cell where the wire touched, without affecting other cells nearby. The researchers say this technique could lead to better ways of studying individual cells or even cell parts, and eventually could produce novel methods of delivering medication.

With the new technique the researchers can, for instance, target cells that have cancer properties (higher cell division rate or abnormal morphology), while sparing their healthy neighbors.

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 precise location. In this way, they 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.

The team members envision many possibilities for this method to trigger the release of the molecule from the wires: photo release, chemical release, and temperature release, or attach many molecules to the nanowires at the same time.

More info: Johns Hopkins University news