INNOVATION ARTICLES THE IDEA SUBMISSION PORTAL FROM MEDTRONIC

For decades, the idea of nanorobots - tiny machines working within the body to deliver drugs, perform diagnostics, perhaps even conduct surgical procedures - have enticed medical innovators and fascinated the general public. A 1966 science fiction film, Fantastic Voyage, featured a miniaturized crew that performed laser surgery on an aneurism. Today nanorobots have become a reality, although there is much more research required before there can be wide-spread application. An exciting area of medical innovation, nanorobot design is not mechanical, but biological, designed via computer modelling.

Dr Aniket Magarkar, researcher at the Centre for Drug Research in the University of Helsinki, is on the forefront of nanorobotics. He acknowledges that the term nanorobot is often misconstrued and on occasion even has included a shot from Fantastic Voyage in presentation slide decks. “Nanorobots have nothing to do with a robot, as such,” he said. “We are trying to mimic what already works in the body.” Magarkar notes that viruses are the perfect example of biological carriers with minimum baggage, but maximum function. “[Nanorobot design is] kind of reverse engineering.” Although therapeutic use is still in exploration stages, the small biological machines are used in various diagnostic settings, for example to deliver and dye cancer cells for surgical visualization.

Although research into nanorobot drug delivery liposomes (DDL) began in 1965, medical investigation has been based on the end result (e.g. cure or positive outcome), rather than the why behind the molecule interaction. “No one has a clue what these nano particles look like once they enter the body,” Magarkar said. While researchers have some ideas, it is difficult because the nano particles are too small to be viewed, even using high powered electron microscopes. “That’s where the computer modelling steps in,” he explained. By knowing what components exist and putting them together via computer software, researchers can use Newton’s Law to formulate the molecule attract/repel forces. Although researchers don’t know all of the interactions, they can in this way generate potential nanorobot designs for drug delivery. “We are looking at cartoon models, derive the physical and chemical principals, and then go ahead,” Magarkar said. He highlights computer modelling offers significant cost saving benefits, providing the ability to test ideas efficiently. However supercomputers are necessary for the greatest speed when running nanorobot models and access can be difficult depending on location. He reported that in Finland it is simply a matter of the researcher booking time, but in other countries, such as the United Kingdom, labs must pay for supercomputer usage, which can affect project budgets.

Magarkar said that time also is an important nanorobot design consideration. When a DDL is injected, the body’s immune system can find the foreign particle within four hours on average. However if a polymer, such as polyethylene glycol (PEG), is attached to the nano particle and changes the surface structure, the immune system has more difficulty recognizing and attaching to it, therefore bloodstream circulation can be increased. PEGylated molecules have been used for about 20 years, with the process well-established. The hope is that nanorobots may eventually be designed to work for up to one month. This can be important in allowing the nanorobot to reach the target area. Part of the aim is to create nanorobots that can sense where they are in the body and deliver the drug at the precise location. In addition to various cancers, other potential applications include multiple sclerosis and HIV. Magarkar noted that concerns with PEGylated molecules are beginning to arise. “If you follow the latest conference materials, there is a debate on whether we’ve over-used PEG and that people are becoming immunogenic. The polymer we are working on now is poly-oxazoline. It is more hydrophilic as compared to PEG,” he said. In previous research they found that the PEG polymer interfered with the peptide so it did not find the target receptor.

Perhaps nanorobots greatest strength may lie in the potential to design truly personal therapies. “We now have the tools to know what genes you have and how they will respond,” Magarkar said. He envisions that in the future there may be a number of nanorobot delivery systems and an array of drugs with various combinations for the best most effective individual approach based on the patient’s genetic information. While exciting, current approval guidelines requiring large trials present a hurdle to this personalized treatment strategy and new guidelines may need to be considered for nano-based medications. “Only 30 nano medicines have been approved since 1995, while 700 normal drug molecules came out in that same period,” Magarkar said. Yet, he remains optimistic. “In 20 years, I think diagnostic nanorobots will be used this way,” he said, but he believes treatment nanorobots are further in the future. “We are still exploring what materials we can use.”