According to a study published in Science Robotics last month, tiny, organic robots called microswimmers will soon travel inside the body, delivering drugs to cancer cells, and they are propelled by light.
Theoretical physicist, Richard Feynman, gave a lecture in 1959 and spoke to the audience about futuristic medicine.
“Although it is a very wild idea, it would be interesting if you could swallow the surgeon,” he told the audience.
“You put the mechanical surgeon inside the blood vessel and it goes into the heart and ‘looks’ around.
“It finds out which valve is the faulty one and takes a little knife and slices it out.”
Medicine is not yet at the level of ‘swallowing the surgeon’ and microswimmers will be more like miniature doctors or nurses making house calls, doing check-ups from inside the body and administering medication.
Microswimmers have been around for over 20 years but previous versions were not organic. They had artificial capsules meant to be filled with drugs, but it was hard for them to move in fluids, such as those inside the body.
The organic microswimmers in the study are based on carbon nitride, which, like a solar cell, absorbs light and produces and stores electric charges.
“The charges react with the fluids inside the body and, combined with the electric field around the particle, make the microswimmers swim,” said a study researcher, Varun Sridhar, to TechXplore.
According to the study, the microswimmers should be able to deliver drugs to parts of the body that are reached by light, such as the skin, transparent tissues and inside the eye.
The researchers are also making the microswimmers infrared-active, so drug delivery could occur to the stomach.
As they travel through the body, organic microswimmers will be able to sense or diagnose hypoxia, which is a low oxygen level. As cancer cells create hypoxia, the microswimmers will release more of the drug they are carrying into those areas.
Each microswimmer will carry 185 per cent of its own mass in drugs because it is spongey and has pores that soak up and bind with more drugs than the previous non-organic microswimmers.
The chemotherapy drug, Doxorubicin, stays bound to a microswimmer for over a month. Still, it can quickly be released in cancer areas of the body by changing its pH or shining a light on the particles. Researchers believe that this could also apply to other drugs.
Organic microswimmers are inexpensive and straightforward to create because they are based on standard, organic precursors such as urea from urine.
Researchers hope that their study can inspire more affordable microrobots which can navigate in biological environments.
