In what may be the most impressive news this week, researchers have engineered a set of magnetic 'tweezers' that can place a nano-scale bead inside a human cell. The development is part of University of Toronto Engineering professor Yu Sun's work.
Probing live cells
Sun and his team have been building robots that can both manipulate and measure single cells. Now, they want to take their work one step further.
"So far, our robot has been exploring outside a building, touching the brick wall, and trying to figure out what's going on inside," said Sun. "We wanted to deploy a robot in the building and probe all the rooms and structures."
Essentially, the researchers want to probe living cells. To do so, they require more advanced technology. "Optical tweezers -- using lasers to probe cells -- is a popular approach," said Xian Wang, the Ph.D. candidate who conducted the research.
Wang designed a novel system that allows for a magnetic iron bead, about 700 nanometers in diameter, to be placed with great precision inside a cell. Wang then controls the bead through a computer-generated algorithm.
"We can control the position to within a couple of hundred nanometers down the Brownian motion limit," said Wang. "We can exert forces an order of magnitude higher than would be possible with lasers."
Studying cancer cells
If you are wondering what the applications are for such a minuscule robotic system, Sun and his team used theirs to study bladder cancer cells. They were effective in measuring cell nuclei in intact cells.
What they found was that the nucleus is not equally stiff in all directions. "It's a bit like a football in shape -- mechanically, it's stiffer along one axis than the other," said Sun. "We wouldn't have known that without this new technique."
But Sun does not want to limit his work to simply examining cancer cells. He believes his research could offer potential new treatments.
"You could imagine bringing in whole swarms of these nano-bots, and using them to either starve a tumor by blocking the blood vessels into the tumor, or destroy it directly via mechanical ablation," said Sun. "This would offer a way to treat cancers that are resistant to chemotherapy, radiotherapy, and immunotherapy."
The research is not by any means ready for clinical deployment, but Sun and his team are already beginning animal experiments.
"It's not quite Fantastic Voyage yet," he said, in reference to the 1966 science fiction film where a submarine crew is shrunk to microscopic size to venture into a human body.
"But we have achieved unprecedented accuracy in position and force control. That's a big part of what we need to get there, so stay tuned!"
Their latest study is published today in Science Robotics.