Nanoengineers send antibiotic-delivering micromotors into the body to treat cancer-causing infection

Nanoengineers have demonstrated for the first time how “micromotors” that measure half the width of a human hair can be used to transport antibiotics through the body.

Nanoengineers at the University of California San Diego tested the micromotors in mice with Helicobacter pylori infections, which can also be found in about two-thirds of the world’s population and while many people will never notice any signs of its presence it can cause peptic ulcers and stomach cancer.

The mice received the micromotors – packed with a clinical dose of the antibiotic clarithromycin – orally once a day for five consecutive days.

Afterwards, nanoengineers evaluated the bacterial count in each mouse stomach and found that treatment with the micromotors was slightly more effective than when the same dose of antibiotic was given in combination with proton pump inhibitors, which also suppress gastric acid production.

Micromotors administered to the mice swam rapidly throughout the stomach while neutralising gastric acid, which can be destructive to orally administered drugs such as antibiotics and protein-based pharmaceuticals.

Because gastric acid is so destructive to traditional antibiotics drugs used to treat bacterial infections, ulcers and other diseases in the stomach are normally taken with additional substances, called proton pump inhibitors.

But when taken over longer periods or in high doses, proton pump inhibitors can cause adverse side effects including headaches, diarrhea and fatigue. In more serious cases, they can cause anxiety or depression.

The micromotors, however, have a built-in mechanism that neutralises gastric acid and effectively deliver their drug payloads in the stomach without requiring the use of proton pump inhibitors.

“It’s a one-step treatment with these micromotors, combining acid neutralisation with therapeutic action,” said Berta Esteban-Fernández de Ávila, a postdoctoral scholar in Wang’s research group at UC San Diego and a co-first author of the paper.

The nanoengineers say that while the present results are promising, this work is still at an early stage.

To test their work, the team is planning future studies to into the therapeutic performance of the micromotors in animals and humans, and will compare it with other standard therapies used to combat stomach diseases.

UC San Diego nanoengineers also plan to test different drug combinations with the micromotors to treat multiple diseases in the stomach or in different sections of the gastrointestinal tract.

Overall, the researchers say that this work opens the door to the use of synthetic motors as active delivery platforms in the treatment of diseases.

Image and video courtesy of the Laboratory for Nanobioelectronics at UC San Diego.

Cheaper, cleaner and with five times more energy: Researchers discover new method for building zinc-air batteries

Lithium-ion batteries could soon be replaced as the power source of choice in electronic devices as researchers have discovered how to build rechargeable zinc-air batteries.

Zinc-air batteries are batteries powered by zinc metal and oxygen from the air, which, thanks to the global abundance of zinc metal, are much cheaper to produce than lithium-ion batteries and can also theoretically store five times more energy  than that of lithium-ion batteries.

Zinc-air batteries  are also much safer and more environmentally friendly.

Featured image courtesy of the University of Sydney

However, their widespread use has been hindered by the fact that, up until now, recharging them has proved difficult. This is due to the lack of electrocatalysts that successfully reduce and generate oxygen during the discharging and charging of a battery.

In the journal Advanced Materials, researchers from the University of Sydney have outlined a new three-stage method to overcome this problem.

“Up until now, rechargeable zinc-air batteries have been made with expensive precious metal catalysts, such as platinum and iridium oxide. In contrast, our method produces a family of new high-performance and low-cost catalysts,” said the study’s lead author Professor Yuan Chen, from the University of Sydney’s Faculty of Engineering and Information Technologies.

University of Sydney researchers used a new method – creating bifunctional oxygen electrocatalysts – which allowed them to build rechargeable zinc-air batteries from scratch.

The researchers also replaced precious metal catalysts with low cost variations, which were produced through the simultaneous control of the composition, size and crystallinity of metal oxides in earth-abundant elements such as iron, cobalt and nickel.

The study’s co-author Dr Li Wei, also from the University’s Faculty of Engineering and Information Technologies, said trials of zinc-air batteries developed with the new catalysts had demonstrated excellent rechargeability – including less than a 10% battery efficacy drop over 60 discharging and charging cycles of 120 hours.

“We are solving fundamental technological challenges to realise more sustainable metal-air batteries for our society,” Chen added.