Microrobots deliver targeted therapy to treat bacterial pneumonia

In mice, the microrobots safely eliminated pneumonia-causing bacteria in the lungs and resulted in 100 per cent survival after 30 days compared to the untreated mice that died within three days after infection. The results are published in Nature Materials.

The microrobots are made of algae cells whose surfaces are dotted with antibiotic-filled nanoparticles. The algae provide movement, which allows the microrobots to manoeuvre and deliver antibiotics directly to more bacteria in the lungs. The nanoparticles containing the antibiotics are made of biodegradable polymer spheres that are coated with the cell membranes of neutrophils, which are a type of white blood cell. These cell membranes absorb and neutralise inflammatory molecules produced by bacteria and the body’s immune system, giving the microrobots the ability to reduce harmful inflammation, which in turn makes them more effective at fighting lung infection.

The work is a joint effort between the labs of nanoengineering professors Joseph Wang and Liangfang Zhang, both at the UC San Diego Jacobs School of Engineering.