Smallest and Fastest Nanomotor Could Advance Drug Delivery

In addition to being the fastest and smallest, these nanomotors can continue spinning for up to 15 hours

2 min read
Smallest and Fastest Nanomotor Could Advance Drug Delivery
Image: Cockrell School of Engineering/The University of Texas at Austin

Engineers at the University of Texas Austin have developed what they claim is the smallest, fastest spinning and longest lasting nanomotor built to date. The engineers have demonstrated that their nanomotor is capable of rotating for 15 continuous hours at a speed of 18 000 rpm. These performance figures are on an entirely different scale to those of similar nanomotors that run anywhere from 14 rpm to 500 rpm and have only rotated for a few seconds or minutes.

The nanomotors, which are described in the journal Nature Communications, were built in a bottom-up manufacturing technique in which nanowires serve as rotors, patterned nanomagnets are the bearings, and quadrupole microelectrodes act as stators.

The entire structure of the nanomotor is smaller than 1 square micrometer, which means it is conceivable that they could fit inside some living cells. The nanomotors are also capable of rapidly mixing and pumping biochemicals as well as moving through liquids.

The researchers coated the nanomotors with a biochemical and started spinning them. They discovered by controlling the spin of the nanomotors they could manage how the biochemical was released. This could prove an effective tool in drug delivery inside the body, they claim.

"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," said Mechanical engineering assistant professor Donglei "Emma" Fan in a press release. "We believe it will help advance the study of drug delivery and cell-to-cell communications."

The researchers were able to control the spin of the nanomotors using a technique developed by Fan in which AC and DC electric fields were used to turn the motor on and off and propel the rotation either clockwise or counterclockwise. With this technique, the researchers found that they could position the nanomotors in a pattern and move them in a synchronized fashion.

In the video below, you can see an animation of how the nanomotors operate and how they could deliver biochemicals.

Earlier this year, researchers at Penn State University demonstrated that a nanomotor could be placed inside human cells and have their movements controlled through the use of both ultrasonic waves and magnetic forces. Because one of the envisioned applications for that work was to have the nanomotor spin inside cancer cells to destroy them, perhaps with this high-rpm nanomotor the destruction would be faster and more complete.

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This CAD Program Can Design New Organisms

Genetic engineers have a powerful new tool to write and edit DNA code

11 min read
A photo showing machinery in a lab

Foundries such as the Edinburgh Genome Foundry assemble fragments of synthetic DNA and send them to labs for testing in cells.

Edinburgh Genome Foundry, University of Edinburgh

In the next decade, medical science may finally advance cures for some of the most complex diseases that plague humanity. Many diseases are caused by mutations in the human genome, which can either be inherited from our parents (such as in cystic fibrosis), or acquired during life, such as most types of cancer. For some of these conditions, medical researchers have identified the exact mutations that lead to disease; but in many more, they're still seeking answers. And without understanding the cause of a problem, it's pretty tough to find a cure.

We believe that a key enabling technology in this quest is a computer-aided design (CAD) program for genome editing, which our organization is launching this week at the Genome Project-write (GP-write) conference.

With this CAD program, medical researchers will be able to quickly design hundreds of different genomes with any combination of mutations and send the genetic code to a company that manufactures strings of DNA. Those fragments of synthesized DNA can then be sent to a foundry for assembly, and finally to a lab where the designed genomes can be tested in cells. Based on how the cells grow, researchers can use the CAD program to iterate with a new batch of redesigned genomes, sharing data for collaborative efforts. Enabling fast redesign of thousands of variants can only be achieved through automation; at that scale, researchers just might identify the combinations of mutations that are causing genetic diseases. This is the first critical R&D step toward finding cures.

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