Micro-submarines navigate through the body to provide targeted drug delivery without the need for external transportation techniques.
Researchers at the University of New South Wales in Australia have demonstrated that micro-submarines powered by nano-motors could travel to a targeted location, for example a diseased organ, and deliver a payload of drugs.
The exciting development in this research is that these micro-submarines don’t need an external stimulus for powering their motors. Previously, the nano machines have used different external driving forces such as light, infrared heat or ultrasound to actively navigate to a specific location . However, the new power behind these devices is provided by variations in the body’s biological environment. As the pH changes, the micro-submarines use a bioactive enzyme called catalyse (CAT) to collect or generate bubbles of gas to adjust their buoyancy, floating up or sinking down to their target.
Longevity.Technology: Using pH power and non-reliance on external transportation factors, as well as the volume of drugs that can be so specifically targeted. This will avoid interaction with healthy tissue, mitigating side-effects, allow drugs with a shorter effective period to be used and allow doctors to use a measured release system, meaning a reduction in the frequency of the dosages taken by the patient. These measures all mean more effective medicine and longer life and healthspans.
The TRL score for this Longevity.Technology domain is currently set at: ‘Late proof of concept demonstrated in real life conditions.’
The TRL score for the technology addressed in this article is: ‘Early proof of concept demonstrated in the laboratory.’
The micro-submarines are made from metal-organic frameworks, honeycomb-like structures with record-breaking surface areas  that are ideal for storing gases. The enormous surface area means millions of drug molecules could be carried by one micro-submarine and each capsule of medicine would contain millions of micro-submarines .
UNSW School of Chemical Engineering and School of Biomedical Engineering researcher Dr Kang Liang said: “Imagine you swallow a capsule to target a cancer in the gastrointestinal tract. 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 the cancer. Once inside the cells, they will be degraded causing the release of the drugs to fight the cancer in a very targeted and efficient way .”
The research team, made up of engineers from UNSW, University of Queensland, Stanford University and University of Cambridge, is excited about other potential uses for the micro-submarines. Dr Liang said: “We are planning to apply this new finding to other types of nanoparticles to prove the versatility of this technique .”