Scientists in Hong Kong have developed biological robots, biohybrids, capable of travelling through the body and degrading cancer cells.
Rather than design complicated nano-robots from scratch, scientists are increasingly looking to build on the elegant infrastructure provided by nature.
Researchers at the Chinese University of Hong Kong are looking to harness the benefits of Spirulina, a microalgae commonly powdered and consumed as a health food. It’s being used as the building blocks for ‘biohybrids’ – tiny cells that, in this case, have been engineered with magnetic particles that enable scientists to guide them around the body.
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Engineering nature
“Rather than fabricate a functional microrobot from scratch using intricate laboratory techniques and processes, we set out to directly engineer smart materials in nature,” said Professor Li Zhang, from the department of mechanical and automation engineering at the Chinese University of Hong Kong.
As a result they were able to make use of the algae’s intrinsic properties. Zhang, who contributed to the study published in Science Robotics, worked alongside an international team to make some vital additions to the algae’s inherent properties. These included coating millions of the tiny algae biohybrids in iron-oxide nanoparticles, which allowed them to be controlled remotely using a targeted magnetic field.
“For instance, because these biohybrid bots have a naturally fluorescent biological interior and magnetic iron-oxide exterior, we can track and actuate a swarm of those agents inside the body quite easily using fluorescence imaging and magnetic resonance imaging,” said Professor Zhang.
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Adapting biohybrids to fight cancer
As part of the research, the team from the Chinese University placed the biohybrids in the stomachs of rats to test their effectiveness. They were able to make the biorobots release cancer-fighting compounds over time.
Developing autonomous systems capable of moving through the body and targeting specific diseases is in many ways the ultimate ambition of researchers in this field. And there are plenty of teams around the world working towards that aim.
The next step for the team from the Chinese University is to prove that its Spirulina-based biohybrid can carry cargo – in this case specific drugs – that can be delivered with more ease and effectiveness than conventional methods, such as pills or injections.
“It’s still not ready for a doctor to use,” Wang said, but within the next ten years it might be. “Everyone wants to realize this fantastic voyage.”
The University of Manchester also had a representative on the research team, Professor Kostas Kostarelos. He said that “creating robotic systems which can be propelled and guided in the body has been and still is a holy-grail in the field of delivery system engineering.”
“Our work takes advantage of some elements offered by nature such as fluorescence, degradability, shape. But we add engineered features such as magnetization and biological activity to come up with a proof-of-concept behind our bio-hybrid, magnetically propelled microrobots.”
“The potential of these bots for controlled navigation in hard-to-reach cavities of the human body makes them promising miniaturized robotic tools to diagnose and treat diseases which is minimally invasive,” he said.
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