A team of scientists has succeeded in eliminating pneumonia microbes in mice. To do this, he has directed a swarm of microrobots made from algae cells and coated with a layer of antibiotic nanoparticles directly into the lungs of animals. They hope that in the future the procedure can be replicated in humans.
The tiny robots are made with algae because they facilitate movement within the lungs , something that is essential for the treatment to be effective. They are also coated in antibiotic nanoparticles .
Although the technology is still in the testing phase, the first indications are very promising: the mice that were treated with the robots were cured of the infection and those that were not treated died within three days.
“Based on the data from this mouse, we see that microrobots could improve the penetration of antibiotics to eliminate bacterial pathogens and save the lives of more patients,” said Victor Nizet, a physician and professor of pediatrics at the University of California, San Francisco. Diego, who has participated in the study.
The nanoparticles in algal cells are made up of tiny polymer spheres coated by the membranes of neutrophils, which are a type of white blood cell. These membranes neutralize inflammatory molecules produced by bacteria and the body’s own immune system . Both nanoparticles and algae degrade naturally.
Harmful inflammation is reduced, which improves the fight against infection, and microbots can deliver treatment exactly where it’s needed . It is the precision that is achieved that makes the technique work so well.
The experiments also found that microrobot treatment was more effective than an injection of antibiotics . What’s more, the injection dose had to be 3,000 times greater than that carried by the algae cells to achieve the same effect in the animals.
“These results show how targeted drug delivery combined with active movement of microalgae improves therapeutic efficacy,” said Joseph Wang, a nanoengineer at UC San Diego.
The bacterium Pseudomonas aeruginosa has been used in the study. This bacterium is the one that usually causes pneumonia in people who have had to be connected to a mechanical ventilator in intensive care. The infection often lengthens the hospital stay and seriously increases the risk of death.
The researchers hope that in the future their microrobot method can be easily applied to patients who are connected to mechanical ventilators and need it. The robots have been introduced to the mice through a tube in the trachea.
The next step is to continue investigating how microrobots interact with the immune system, to then scale up the work and test it in larger animals and finally in humans.
“Our goal is to selectively deliver drugs to more difficult parts of the body, such as the lungs,” says chemical engineer Liangfang Zhang of the University of California, San Diego. “And we want to do it in a safe, easy, biocompatible and durable way.” “That’s what we’ve shown in this work,” he says.
Referencia: Zhang, F., Zhuang, J., Li, Z. et al. Nanoparticle-modified microrobots for in vivo antibiotic delivery to treat acute bacterial pneumonia. Nature Materials. 2022. DOI: https://doi.org/10.1038/s41563-022-01360-9