Overview

Tiny microrobots invisible to the naked eye could soon be delivering medication directly to affected organs inside the human body.

Mircrorobots — a remarkable invention created by engineers at the University of California San Diego — were injected in mice to clear life-threatening cases of bacterial pneumonia. The microrobots removed all traces of pneumonia-causing bacteria in the mice’s lungs, ensuring 100% survival in subject who received the treatment. Other specimens that were not administered the treatment expired within three days of the infection.

Science and Other Stuff to know

According to the university, the microrobots consist of algae cells “whose surfaces are speckled with antibiotic-filled nanoparticles.” The algae provide critical movement for the microrobots, enabling them to swim around and administer antibiotics directly to bacteria in the lungs. Nanoparticles that carry the antibiotics to affected areas are formed using minuscule biodegradable polymer spheres coated with cell membranes of neutrophils, a type of white blood cell that acts as the body’s first line of defense.

While in action, the membrane absorbs and offsets the bacteria molecules causing the disease, giving microrobots the ability to heal inflammation and fight lung infection.

Researchers ran the tests on mice infected with a potentially fatal form of pneumonia that forces patients onto mechanical ventilation in intensive care units. The microrobots were delivered to the lungs through a tube inserted in the windpipe. To the team’s delight, the infection disappeared after a week, with all treated mice surviving well past 30 days. The researchers found that the treatment was far more effective than injections as well.

So what?

Not only are the results a promising development for delivering targeted medication to affected organs in the body and potentially avoiding any and all side effects of medication on other organs, the results also show the procedure is far more cost-efficient.

What does that mean? The antibiotics’ dose administered to mice through the microrobots was 3,000 times less than that used in an IV injection to arouse a similar response to the disease. Part of the reason is the accuracy of administering the dosage. The microrobots take the medication directly where it’s needed, while an injection puts the same in the bloodstream. Only a fraction of the dosage reaches the organs, while the rest is diffused. This is the reason a larger dose is required to make the medication more effective.

The microrobots’ ability to be highly effective at a fraction of the cost could revolutionize public health delivery systems around the globe. Governments could save hundreds of millions of dollars they spend on medicines, while the procedure could also drastically reduce the cost of acquiring medicine for private consumers, especially in the developing world.

What’s next?

Work on the microrobots is still in the proof-of-concept stage, meaning much more testing is required to study the microrobots’ interaction with, and reaction to, the immune system. Scientists plan to scale the treatment to larger animals and eventually, to humans. So widespread use of microrobot-ic treatment could still be years away.

But that would not deter Professor Joseph Wang — who led the study with Professor Liangfang Zhang at Jacobs School of Engineering — to continue believing that he was “pushing the boundary further in the field of targeted drug delivery”.