A team of researchers led by Dr Jinyao Tang of the Department of Chemistry, the University of Hong Kong, has developed the world’s first light-seeking synthetic Nano robot. With size comparable to a blood cell, those tiny robots have the potential to be injected into patients’ bodies, helping surgeons to remove tumors and enabling more precise engineering of targeted medications.
The findings have been published in October earlier in leading scientific journal Nature Nanotechnology.
It has been a dream in science fiction for decades that tiny robots can fundamentally change our daily life. The famous science fiction movie “Fantastic Voyage” is a very good example, with a group of scientists driving their miniaturized Nano-submarine inside human body to repair a damaged brain. In the film “Terminator 2”, billions of Nanorobots were assembled into the amazing shapeshifting body: the T-1000. In the real world, it is quite challenging to make and design a sophisticated Nano robot with advanced functions.
The Nobel Prize in Chemistry 2016 was awarded to three scientists for “the design and synthesis of molecular machines”. They developed a set of mechanical components at molecular scale which may be assembled into more complicated Nano machines to manipulate single molecule such as DNA or proteins in the future. The development of tiny nanoscale machines for biomedical applications has been a major trend of scientific research in recent years. Any breakthroughs will potentially open the door to new knowledge and treatments of diseases and development of new drugs.
One difficulty in Nanorobot design is to make these nanostructures sense and respond to the environment. Given each Nanorobot is only a few micrometer in size which is ~50 times smaller than the diameter of a human hair, it is very difficult to squeeze normal electronic sensors and circuits into Nanorobots with reasonable price. Currently, the only method to remotely control Nanorobots is to incorporate tiny magnetic inside the Nanorobot and guide the motion via external magnetic field.
The Nanorobot developed by Dr Tang’s team use light as the propelling force, and is the first research team globally to explore the light-guided Nanorobot and demonstrate its feasibility and effectiveness. In their paper published in Nature Nanotechnology, Dr Tang’s team demonstrated the unprecedented ability of these light-controlled Nanorobots as they are “dancing” or even spell a word under light control. With a novel Nanotree structure, the Nanorobots can respond to the light shining on it like moths being drawn to flames. Dr Tang described the motions as if “they can “see” the light and drive itself towards it”.
The team gained inspiration from natural green algae for the Nanorobot design. In nature, some green algae have evolved with the ability of sensing light around it. Even just a single cell, these green algae can sense the intensity of light and swim towards the light source for photosynthesis. Dr Jinyao Tang’s team spent three years to successfully develop the Nanorobots. With a novel Nanotree structure, they are composed of two common and low-price semiconductor materials: silicon and titanium oxide. During the synthesis, silicon and titanium oxide are shaped into nanowire and then further arranged into a tiny Nanotree heterostructure.
Dr Tang said: “Although the current Nanorobot cannot be used for disease treatment yet, we are working on the next generation nanorobotic system which is more efficient and biocompatible.”
“Light is a more effective option to communicate between microscopic world and macroscopic world. We can conceive that more complicated instructions can be sent to Nanorobots which provide scientists with a new tool to further develop more functions into Nanorobot and get us one step closer to daily life applications,” he added.
Researchers from Polytechnique Montréal, Université de Montréal and McGill University have just achieved a spectacular breakthrough in cancer research. They have developed new nanorobotic agents capable of navigating through the bloodstream to administer a drug with precision by specifically targeting the active cancerous cells of tumours. This way of injecting medication ensures the optimal targeting of a tumour and avoids jeopardizing the integrity of organs and surrounding healthy tissues. As a result, the drug dosage that is highly toxic for the human organism could be significantly reduced.
This scientific breakthrough has just been published in the prestigious journal Nature Nanotechnology in an article titled “Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.” The article notes the results of the research done on mice, which were successfully administered nanorobotic agents into colorectal tumours.
“These legions of nanorobotic agents were actually composed of more than 100 million flagellated bacteria – and therefore self-propelled – and loaded with drugs that moved by taking the most direct path between the drug’s injection point and the area of the body to cure,” explains Professor Sylvain Martel, holder of the Canada Research Chair in Medical Nanorobotics and Director of the Polytechnique Montréal Nanorobotics Laboratory, who heads the research team’s work. “The drug’s propelling force was enough to travel efficiently and enter deep inside the tumours.”
When they enter a tumour, the nanorobotic agents can detect in a wholly autonomous fashion the oxygen-depleted tumour areas, known as hypoxic zones, and deliver the drug to them. This hypoxic zone is created by the substantial consumption of oxygen by rapidly proliferative tumour cells. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.
But gaining access to tumours by taking paths as minute as a red blood cell and crossing complex physiological micro-environments does not come without challenges. So Professor Martel and his team used nanotechnology to do it.
Bacteria with compass
To move around, bacteria used by Professor Martel’s team rely on two natural systems. A kind of compass created by the synthesis of a chain of magnetic nanoparticles allows them to move in the direction of a magnetic field, while a sensor measuring oxygen concentration enables them to reach and remain in the tumour’s active regions. By harnessing these two transportation systems and by exposing the bacteria to a computer-controlled magnetic field, researchers showed that these bacteria could perfectly replicate artificial nanorobots of the future designed for this kind of task.
“This innovative use of nanotransporters will have an impact not only on creating more advanced engineering concepts and original intervention methods, but it also throws the door wide open to the synthesis of new vehicles for therapeutic, imaging and diagnostic agents,” Professor Martel adds. “Chemotherapy, which is so toxic for the entire human body, could make use of these natural nanorobots to move drugs directly to the targeted area, eliminating the harmful side effects while also boosting its therapeutic effectiveness.”