Boldly going where no robot has gone before, a new micro-machine from Purdue University could vault its way to the forefront of targeted drug delivery.
Scientists at the university’s School of Mechanical Engineering have created a microrobot, “as tiny as a few human hairs,” designed to cartwheel upstream through the colon, gradually unleashing drugs on-site. Those acrobatics should allow the robot to traverse the organ’s harsh terrain, the team said in a release.
As for why the team chose the colon, it has an easy point of entry, and it’s a particularly tough environment to navigate—a chance to prove the small-but-mighty machine has what it takes to deploy drugs there, and potentially tumble its way through other organs, too.
“Moving a robot around the colon is like using the people-walker at an airport to get to a terminal faster,” Luis Solorio, assistant professor at Purdue University’s Weldon School of Biomedical Engineering, said. “Not only is the floor moving, but also the people around you. In the colon, you have all these fluids and materials that are following along the path, but the robot is moving in the opposite direction. It’s just not an easy voyage.”
The machine is too small to tote a battery, so it’s powered and wirelessly controlled externally by a spinning magnetic field, which in turn causes the robot to somersault its way through the body.
The robot also comes equipped with a polymer coating, which keeps its payload from acting on other organs before it reaches its target site, the team said.
So far, researchers have successfully piloted the robot through the colons of mice, publishing the results in the journal Micromachines. The team inserted the microrobot into the animals’ rectums via a saline solution, observing the machines’ movement in real time using ultrasound.
The team also maneuvered its robot through samples of pig colons and showed it could gradually release drugs over time in a vial of saline. When loaded up with a fluorescent mock drug, the robot tumbled its way through the saline solution, dispersing its payload over the course of an hour.
For the system to work in humans, the team would likely need to deploy “dozens” of microrobots, but that could also allow the machines to “target multiple sites with multiple drug payloads,” Craig Goergen, whose research group carried out imaging work on the tech, said.
Plus, the team thinks its robot could do more than just haul drugs.
"From a diagnostic perspective, these microrobots might prevent the need for minimally invasive colonoscopies by helping to collect tissue. Or they could deliver payloads without having to do the prep work that’s needed for traditional colonoscopies,” Goergen said.