Nano-sized machines swimming in stomachs can now treat infections

16 Aug 2017

A microscopic view of a micromotor propelling itself through gastric acid. Image: Screenshot from a video provided by the University of California San Diego

Nano-sized micromotors have been used in a person’s stomach to treat bacterial infections for the first time in a major breakthrough.

In the near future, nano-sized micromotors swimming in your stomach could be used to treat a variety of different infections, having been demonstrated for the first time, according to a paper recently published in Nature Communications.

Developed by a team of nano-engineers from the University of California San Diego, the specially built micromotors offer a promising new method for treating stomach and gastrointestinal tract diseases with acid-sensitive drugs.

Future Human

In typical oral delivery medication, one of the greatest challenges is limiting the corrosive effects of gastric acid in the human digestive system, which can destroy the medication before it reaches the affected area.

This is usually prevented by taking the medication with substances called proton pump inhibitors that suppress gastric acid production, but their long-term use can result in a number of side effects, including headaches and diarrhoea.

That is why the research team proposed building nano-scaled micromotors, which would be designed with a built-in mechanism to neutralise gastric acid and effectively deliver their drug payloads in the stomach without the need for proton pump inhibitors.

How it works

It does this with help from a spherical magnesium core coated with a protective layer of titanium dioxide, followed by a layer of the antibiotic clarithromycin.

The swimming micromotors are then able to stick to the wall with an outer layer made of a positively charged polymer called chitosan.

Acting as the motors’ engine, the magnesium core reacts with the gastric acid in the stomach, generating a stream of hydrogen microbubbles, propelling them to the organ’s walls.

This chemical reaction also has another benefit in that it temporarily reduces the amount of acid in the stomach, allowing the antibiotic in the motor to be released to treat the infection.

While still in an early stage, the research team has found success in testing, and it has proven more effective than typical oral medication in mice.

It is now planning future studies to further evaluate the therapeutic performance of the micromotors in vivo and compare it with other standard therapies against stomach diseases.

Colm Gorey was a senior journalist with Silicon Republic