Cancer killer is a micro marvelLocal | Sum Lok-kei 29 Nov 2017
Two Chinese University of Hong Kong researchers have developed the first biodegradable microbot - a microscopic robot - with the "unexpected" ability to kill cancer cells in a laboratory setting.
The researchers have tested the technology, which they say may also be able to cure eye diseases and detect illnesses, on live mice by injecting thousands of microbots into them. However, they hope to use it to treat humans within five to 10 years.
Zhang Li, an associate professor of the university's department of mechanical and automation engineering, said the microbot is made of two materials, one natural and the other artificial.
The team dipped a type of algae, known as spirulina, which has a helical structure, into a pool of iron-oxide nano-particles. This resulted in the creation of a microbot that, according to Zhang, is "20 times narrower in diameter than a hair."
Zhang said spirulina is florescent in nature, which allows researchers to track it with a fluorescence microscope after the microbots have been injected into a subject.
Co-researcher Yan Xiaohui explained that the florescent light from the microbot dims when it is nears a tumor as it releases acidic compounds. The iron-oxide particles that are attached to the surface of the algae allow scientists to control the microbot's movement remotely via magnetic fields.
"Rather than fabricate a functional microbot from scratch using intricate laboratory techniques and processes, we set out to directly engineer smart materials in nature," Zhang said.
One of the major breakthroughs, according to the researchers, is that the microbot is biodegradable in the human body as the algae can be used as a source of nutrition, while the iron can be absorbed.
Meanwhile, Yan said the team was surprised to find that the algae releases compounds that is only harmful to certain cancer cells and has no effect on healthy cells.
When cervical cancer cells were placed in a test tube with the microbot, only 10 percent survived after two days.
However, the research team are unsure whether the microbot will be as effective when placed inside a human body. Researchers said the next step will be to attach drugs to the microbot in order for it to serve as a "vessel" to carry the drugs to areas of the body that are difficult to reach.
To study the microbot's effect on humans, Zhang said more government funding would be required, along with the involvement of medical professionals.