Microrobots, created by nanoengineers at the University of California, San
Diego, can carry medication, swim about in the lungs, and be used to treat
life-threatening instances of bacterial pneumonia.
The microrobots successfully eradicated the bacterium that causes pneumonia
in the lungs of mice, resulting in 100% survival. In contrast, mice that
were not treated all passed away three days after becoming ill.
Nature Materials reported the findings on September 22.
The algae cells used to create the microrobots had antibiotic-filled
nanoparticles all over their surfaces. The microrobots may swim about and
administer medications directly to more germs in the lungs because to the
mobility provided by the algae. The small biodegradable polymer spheres that
make up the antibiotic-containing nanoparticles have neutrophil cell
membranes coated on them. Neutrophils are a kind of white blood cell. These
cell membranes are unique in that inflammatory chemicals generated by
bacteria and the body's immune system are absorbed and neutralized by them.
The microrobots can do this, which enhances their capacity to battle lung
infection by lowering damaging inflammation.
Both Joseph Wang and Liangfang Zhang, professors of nanoengineering at the
UC San Diego Jacobs School of Engineering, collaborated on the project. Wang
is a global expert in the study of micro- and nanorobotics, and Zhang is a
global expert in the creation of nanoparticles that resemble living cells to
treat illnesses and infections. Together, they have paved the way for the
creation of miniature drug-delivery robots that can be used to safely treat
bacterial infections in the
blood
and
stomach
in living animals. The most recent aspect of their work is treating
bacterial lung infections.
"Our objective is to perform targeted medicine delivery into
harder-to-reach areas of the body, such as the lungs. And we want to
accomplish it in a way that is long-lasting, straightforward, safe, and
biocompatible," added Zhang. "In our work, we have shown that to be the
case."
The scientists treated mice with Pseudomonas aeruginosa-caused acute
pneumonia using microrobots to prevent death in certain cases. Patients
receiving mechanical ventilation in the critical care unit are frequently
affected by this kind of pneumonia. Through a catheter placed in the mice's
windpipe, the researchers delivered the microrobots to their lungs. After
one week, the infections were entirely under control. Mice not given the
microrobot treatment perished after three days, but every mouse treated with
them lived for more than 30 days.
A bloodstream IV infusion of antibiotics was not as successful as the
treatment with the microrobots. In order to accomplish the same impact, the
latter needed an antibiotic dosage that was 3000 times larger than what was
employed in the microrobots. For instance, an IV injection delivered 1.644
milligrams of antibiotics per mouse, whereas a dosage of microrobots
delivered 500 nanograms.
The team's strategy works so well because it delivers the drug directly to
the patient's area of need rather than dispersing it throughout the
body.
These findings demonstrate how active mobility from the microalgae and
focused medication administration might enhance therapeutic effectiveness,
according to Wang.
Sometimes, very little of the antibiotics administered by IV will reach the
lungs. Because of this, many of the current antibiotic treatments for
pneumonia don't work as well as they should, which causes extremely high
mortality rates in the sickest patients, according to Victor Nizet, a
professor at the UC San Diego School of Medicine and Skaggs School of
Pharmacy and Pharmaceutical Sciences and a co-author on the study with Wang
and Zhang. The microrobots may be able to increase antibiotic penetration to
kill bacterial infections and save the lives of more people, according to
the mice study.
And if the idea of inhaling algae cells makes you queasy, the researchers
claim that this method is secure. Following therapy, the algae and any
lingering nanoparticles are effectively digested by the body's immune cells.
Nothing hazardous is left behind, according to Wang.
The proof-of-concept phase of the project is currently ongoing. To
precisely understand how the microrobots interact with the immune system,
the team intends to do further fundamental study. Prior to testing it on
larger animals and eventually on people, the microrobot therapy will also
undergo research to verify it and be scaled up.
In the area of tailored medicine delivery, "we're pushing the envelope even
farther," added Zhang.
In vivo antibiotic administration via nanoparticle-modified microrobots to
treat acute bacterial pneumonia is the topic of the study.
This work is supported by the National Institutes of Health
(R01CA200574).
