Tiny nanomotors powered by ultrasonic waves and steered with magnets have been deployed in living human cells for the first time ever.
Scientists at Penn State University manoeuvred the long, thin bits of metal and those involved have high hopes for the future of the technology.
Tom Mallouk, Evan Pugh Professor of Materials Chemistry and Physics at the university, said: "We might be able to use nanomotors to treat cancer and other diseases by mechanically manipulating cells from the inside.
"Nanomotors could perform intracellular surgery and deliver drugs noninvasively to living tissues."
Nanomotors are not new - they've previously been used "in vitro" in a laboratory apparatus but the first-generation motors required toxic fuels marmful to living human tissue.
The breakthrough came when Mallouk and French physicist Mauricio Hoyos discovered they could be powered by ultrasonic waves.
For their experiments, the team uses HeLa cells, an immortal line of human cervical cancer cells that typically is used in research studies.
These cells ingest the nanomotors, which then move around within the cell tissue, powered by ultrasonic waves. At low ultrasonic power, Mallouk explained, the nanomotors have little effect on the cells.
But when the power is increased, the nanomotors spring into action, moving around and bumping into organelles -- structures within a cell that perform specific functions.
The nanomotors can act as egg beaters to essentially homogenize the cell's contents, or they can act as battering rams to actually puncture the cell membrane.
Mallouk said: "One dream application of ours is Fantastic Voyage-style medicine, where nanomotors would cruise around inside the body, communicating with each other and performing various kinds of diagnoses and therapy.
"There are lots of applications for controlling particles on this small scale, and understanding how it works is what's driving us."