Chemicals are well suited to kill bacteria, but as antibiotic resistance increases, new methods will be needed. “Mechanical” solutions are particularly promising, such as rice university’s “nanodrills” that can penetrate the cell walls. Now, the team has shown that the device is resistant to large organisms such as worms and water fleas.
“Nano drills” are actually tiny rotors that rotate up to 3 million times per second when activated by light. That way, they can drill into cells, kill targets directly, or make it easier for other methods, such as drugs, to get the job done. Just a few months ago, the Rice University team used it to kill cancer cells and drug-resistant bacteria, and now they have been moved to larger targets.
Those previous tests were done in a laboratory dish, but for the new study, the researchers tried to use “nano drills” in organisms – one worm called the beautiful hidden worm and the other a plankton called a water flea.
The “nanodrills” caused the worm’s skin to lose its pigment, killing 70 percent of them over the next few days. At the same time, in plankton, the drill cuts off many outer limbs and kills most of the water fleas.
James Tour, lead researcher on the study, said: “This work shows that whole organisms, such as small worms and water fleas, can be killed by nanomachines that get into them. This is not only single-cell death, but also the entire organism, which causes thousands of cells to die. “
In a subsequent test, the researchers shifted the target to a larger animal, the mouse. They smeared a local mixture containing micromachines on the skin of mice, and once activated, the drill bits caused skin damage and ulcers. While this doesn’t sound good for poor animals, the researchers say the test shows how “nanodrills” will eventually be used in beneficial ways. They can be used on human skin to penetrate melanoma, kill parasites such as worms or fight eczema and other skin diseases.
The idea is that “nanodrills” can be “trained” to target only certain cells so that they don’t harm healthy human cells.
The study was published in the journal ACS Applied Materials and Interfaces.