Tiny robots made of algae are swimming through the lung fluids of mice, delivering antibiotics straight to the bacteria that cause a deadly form of pneumonia.
It’s happening now in UC San Diego labs and it shows the tremendous potential of microrobotics. Nanoparticles, loaded with medicine, are attached to the microrobots and introduced into the lungs.
“They can actively swim in the body fluid, dip into the thick part of the tissue and carry a lot of these therapeutic payloads to the disease site, and then very effectively kill the bacteria,” said professor of nanoengineering Liangfang Zhang, one of the lead researchers.
Zhang said the results of the experiment were dramatic. The mice treated with drugs in a conventional way died within days.
“But when we loaded the drugs into our formulation — the nanoparticle and the algae system — we found that all the animals survived,” he said. “We achieved a remarkable 100% survival rate from the study.”
Anyone who has swallowed an aspirin knows one very conventional way of delivering drugs. The medication is ingested and is carried throughout the body.
“You take the pill and it's all passive. The drug goes slowly by diffusion,” said Joseph Wang, a distinguished professor of nanoengineering at UC San Diego.
“By having dynamic active delivery, we are accelerating targeted delivery to the right location.”
Wang’s lab at UCSD shows many examples of microrobots, designed to navigate the body’s channels and cavities. The algae robot is organic, and swims with its flagella. Another robot, made from zinc, reacts with gastric fluid and generates hydrogen gas, which propels it like a true rocket.
Wang points out the algae robot is not attracted to the bacteria, but they move so effectively through the fluids of the lung that it greatly improves the dispersion of the drug. Wang has actually loaded robots into pills, including aspirin.
“This we showed with pigs, actually, and showed that when you have the active delivery there is much better uptake by the blood,” Wang said.
The purpose of the research, of course, is not to treat pigs or mice, but humans. Zhang said the study of algae robots in the lungs is very innovative and experimental, and human trials are still a ways away.
“We demonstrated the feasibility of the technology and what I foresee is, we need to study more to demonstrate the efficacy in large animal species,” he said, “before we can translate it to a human study.”
