Tiny swimming robots treat deadly pneumonia in mice
Colored SEM image of a pneumonia-fighting microrobot made of an algae cell (green) covered with biodegradable polymer nanoparticles (brown). The nanoparticles contain antibiotics and are coated with neutrophil cell membranes. Credit: Fangyu Zhang and Zhengxing Li

Microrobots, which can swim around in the lungs, deliver medication and be used to clear up life threatening cases ofbacterial pneumonia, have been developed by the University of California San Diego.

In mice, the microrobots were able to eliminate the pneumonia-causingbacteria in the lungs. The mice were all dead within three days.

The results are published in September.

The surface of the microrobots are covered with antibiotics. Microrobots are able to deliver antibiotics directly to morebacteria in the lungs thanks to the movement of thealgae. A type of white blood cell, the neutrophils, are coated with the particles in the antibiotics. The cells of the body's immune system are prone to producing inflammatory molecules. Microrobots are more effective at fighting lung infections due to the fact that they can reduce harmful inflammation.

Two labs of professors at the UC San Diego Jacobs School of Engineering are working together on a project. Wang and Zhang are both world leaders in their fields of research. They have developed tiny drug-delivering robots that can be used in live animals to treat infections in the stomach and blood. They are treating lung infections.

Our goal is to deliver drugs into the lungs. "We want to do it in a way that is safe, easy, and long lasting. We've shown that in this work.

Microrobots were used to treat mice with a potentially fatal form of pneumonia. In the intensive care unit, this form of pneumonia can affect patients. The researchers put the microrobots in the mice's lungs. After a week, the infections were completely cleared up. The mice that were treated with the microrobots lived past 30 days.

The treatment with the microrobots was more effective than an IV. The latter needed 3000 times the amount of antibiotics used in the microrobots to achieve the same result. The amount of antibiotics provided by a dose of microrobots was 500 times greater than the amount of antibiotics provided by an IV injection.

The team's approach is so effective because it puts the medication where it needs to go.

Targeted drug delivery combined with active movement from the microalgae improves therapeutic efficacy.

Some antibiotics will get into the lungs with an IV injection. Victor Nizet is a professor at the UC San Diego School of Medicine and the Skaggs School of Pharmacy and Pharmaceutical Sciences. The data shows that the microrobots could improve antibiotic penetration and save more patients' lives.

The researchers say that this approach is safe if you're squeamish. The body's immune cells digest any remaining particles. Wang said that there was nothing toxic left.

The work is still in its early stages. More basic research will be done to understand how the microrobots interact with the immune system. Next steps include studies to confirm the treatment and scale it up before testing it in larger animals and eventually in humans.

The field of targeted drug delivery is being pushed further.

There is a research paper on microrobots for antibiotic delivery.

More information: Liangfang Zhang, Nanoparticle-modified microrobots for in vivo antibiotic delivery to treat acute bacterial pneumonia, Nature Materials (2022). DOI: 10.1038/s41563-022-01360-9. www.nature.com/articles/s41563-022-01360-9 Journal information: Nature Materials