University of Texas engineers have built the smallest and fastest nanomotor that could fit inside a cell and deliver drugs, the latest development in research efforts to use nanotechnology in medicine.
There has been a flurry of studies recently about harnessing nanotechnology for medical purposes.
Researchers have been busy devising techniques to fabricate and deploy these miniature machines for drug delivery purposes.
For example, South Korean scientists have used “bacteriobots” that can destroy cancer cells in mice while sparing normal cells.
Another group of researchers have shown how folding “DNA origami nanobots” could deliver specific drugs based on the type of cell it encounters, while another group of scientists at Harvard are building a DNA nanodevice that could mimic viruses and target cancer cells.
To power these and future microscopic medical devices, scientists have been experimenting with nanomotors.
Their early research have yielded nanomotors with a lot of potential, but were either too complicated to build or often run low on power.
Now, researchers at the Cockrell School of Engineering at the University of Texas at Austin announced that they have created the smallest, fastest nanomotor that is better than earlier-conceived models.
The medical device, more than 500 times smaller than a grain of salt, could fit inside a cell and deliver drugs from around or within cells.
Building upon her prior research on nanotech assembly using AC and DC electric fields, mechanical engineering assistant professor, Dr. Donglei “Emma” Fan, with the help of her team, designed a simple three-part nanomotor consisting of nanomagnets, nanowires and microelectrodes.
The medical device is capable of converting electrical energy into mechanical energy. It is also designed to swim through fluids as well as mix and pump chemicals.
As documented in the study published in Nature Communications, the team was able to demonstrate the unprecedented reliability and power of the nanomotor, which spun for 15 hours straight at a rotating speed of up to 18,000 RPM - equivalent to a jet engine motor.
In comparison, most other nanomotors could only spin at maximum speeds of 500 RPM for a few minutes.
The new nanomotor could be controlled from outside: turned on and off, clockwise and counterclockwise.
Moreover, multiple nanomotors could spin in sync, demonstrating their potential to deliver drugs on-demand.
To test this capability, the team coated the device’s surface with biochemicals. Their experiment showed that the faster the nanomotor spun, the faster the biochemicals were released.
“We were able to establish and control the molecule release rate by mechanical rotation, which means our nanomotor is the first of its kind for controlling the release of drugs from the surface of nanoparticles,”
Fan said in a statement.
“We believe it will help advance the study of drug delivery and cell-to-cell communications.”
This Ultrahigh-Speed Rotating Nanoelectromechanical System (NEMS) technology could be used someday to deliver anti-cancer drugs, insulin for diabetics, or treat other diseases using selective cell therapy.
In the study paper, the researchers wrote abut the significance of their work, saying,
“Nanoelectromechanical System (NEMS) devices, consisting of both electronic and mechanical components are emerging as the next-generation technology that can significantly impact people’s lives. It has intrigued the research community for over a decade, not only due to the rich fundamental science where devices are made on the nanoscale, but also due to the high potential of making technical breakthroughs in various areas including robotics, biomedical research, and optoelectronics.”
“The multilevel innovations reported in this research may bring transformative impact to fields including NEMS, bioNEMS, microfluidics, and lab-on-a-chip architectures,”
The UT Austin researchers conducted the experiment in a nonbiological setting. In planned trials, they hope to replicate their findings using live cells, and then put these nanomotors in future nanodevices that can seek out and destroy harmful cells.