A team of engineers at the University of New South Wales (UNSW) in Australia has come up with micro-submarines that draw their power from nano-motors. These micro-submarines are able to navigate through the human body for the sake of delivering medicine to sick organs without requiring any kind of surgery.
Dr Kang Liang, School of Biomedical Engineering and School of Chemical Engineering at UNSW, said, ‘We already know that micro-motors use different external driving forces—such as light, heat, or magnetic field—to actively navigate to a specific location. In this research, we designed micro-motors that no longer rely on external manipulation to navigate to a specific location. Instead, they take advantage of variations in biological environments to navigate themselves automatically.’
As it happens, the human body has a variety of touch points that can be used as guides. For instance, Liang’s team relied on the pH levels of the human body. Since our bodies are mostly water-based and spend quite an amount of energy for maintaining these pH levels within healthy ranges, the micro-submarines will be able to self-adjust the pH levels for maintaining their buoyancy while they traverse the human bodies.
Liang said, ‘Most micro-motors travel in a two-dimensional fashion. But in this work, we designed a vertical direction mechanism. We combined these two concepts to come up with a design of autonomous micro-motors that move in a 3D fashion. This will enable their ultimate use as smart drug delivery vehicles in the future.’
The micro-submarines created by Dr Kang Liang and his team travel in the form of controlled swarms. According to the team, the future might contain millions of these micro-submarines in a pill. Each of these micro-submarines would house millions of the drug molecules. This would lead to creating an effective treatment for patients. Liang further said, ‘Once, in the gastrointestinal fluid, the micro-submarines carrying the medicine could be released. Within the fluid, they could travel to the upper or bottom region, depending on the orientation of the patient. The drug-loaded particles can then be internalized by the cells at the site of cancer. Once inside the cells, they will be degraded, causing the release of the drugs to fight cancer in a very targeted and efficient way.’
These micro-submarines, as of now, are still in the proof of concept phase. However, they would be metal-organic frameworks that will have micro-motor systems that house a bioactive enzyme known as catalase. Catalase is among the list of most efficient enzymes that are present in the human body. It is capable of decomposing more than millions of hydrogen peroxide molecules per second. Liang said, ‘We are planning to apply this new finding to other types of nanoparticles to prove the versatility of this technique.’
These tiny robots might not be travelling through our body soon enough, but just like space travel, such a future is drawing closer steadily.