Turning white blood cells into medicinal microrobots with light
Neutrophils could one day be used to deliver drugs in the body.
Medicinal microrobots are currently being developed to allow doctors to better treat and prevent diseases.
Most of these are made with synthetic materials that trigger immune responses in small animals, causing them to be cleared from the body before they can do their job.
Now, scientists have reported for the first time their success using cells already present in the body – white blood cells called neutrophils – as natural, biocompatible microrobots in living fish.
The team used lasers to precisely control the neutrophils, or ‘neutrobots’, to perform multiple tasks – showing they could someday deliver drugs to precise locations in the body.
In a new study published in
ACS Central Science, the authors write that the neutrobots “could hold great promise for the active execution of complex medical tasks in vivo, with great potential utility in the treatment of inflammatory diseases”.
Instead of requiring injections or taking capsules to get the microrobot inside an animal or person, they propose using cells already present in the body as a less invasive alternative that won’t set off the immune system.
“Unlike traditional medical microdevices, this neutrophil microcraft is free from artificial microstructures and invasive implantation processes, thus avoiding complicated preparation technology and tissue damage,” the study authors say.
Neutrophils already naturally pick up nanoparticles and dead red blood cells, and can migrate through blood vessels into adjacent tissues, so they are good candidates for becoming microrobots.
It’s been shown that neutrophils can be guided and moved around by lasers in lab dishes, but the researchers – from Jinan University, China – wanted to see if this approach would work inside living animals.
They manipulated and manoeuvred neutrophils in zebrafish tails, using focused laser beams as remote optical tweezers.
They found that the neutrobots could be moved up to 1.3 micrometres per second, which is three times faster than a neutrophil naturally moves.
The study, they say, advances the possibilities for targeted drug delivery and precise treatment of diseases.