11 August, 2017
The pace of change in modern medicine has been staggering. Diseases that once killed millions have now been eradicated, and treatments for diseases have never been more effective. The 21st century comes with its own challenges, though–a higher life expectancy brings an increased burden of age-related diseases. Global populations are growing, but so too is the number of premature deaths caused by cardiovascular diseases and substance abuse. Into this fray, doctors and medical researchers must go, but they’re not alone. Device manufacturers, engineers and materials scientists are working to develop smaller, smarter, cheaper and more reliable technologies, to answer some of the biggest questions facing future medicine.
According to the World Health Organisation, the number of new cancer cases is expected to rise by about 70% in the next two decades. So, there’s a growing need for new and improved diagnosis techniques and treatments. MacDiarmid researcher and postdoctoral fellow at Victoria University of Wellington, Dr Renee Goreham, is investigating a class of materials that could make cancer easier to detect, and it starts with an MRI (magnetic resonance imaging) machine.
MRI is one of our main diagnostic tools. It uses magnetism and radio waves to build up a picture of a person’s internal organs, allowing radiographers to locate any signs of cancer. It relies on a contrast agent, injected into the body, to improve visibility, and this is where nanotechnology can help.
“The problem with the MRI contrast agents currently in use is that they have a low resolution, which limits the minimum size of cancerous cells they can identify,” explained Dr Goreham. “They’re also toxic, so can cause serious side-effects to patients.” Dr Goreham’s solution, now funded by a National Science Challenge Seed grant, was to develop a contrast agent made from nanoclusters of silver atoms. This non-toxic nanomaterial is predicted to be responsive to magnetic fields, and it also fluoresces. Together, these properties make it possible to analyse cancerous cells with multiple complementary techniques, increasing the likelihood of an earlier diagnosis.
In addition, Dr Goreham is exploring the use of exosomes–tiny particles, continuously produced by most cells in our bodies. Once thought to be trash carriers for cells, they’re now known to be a vital communication tool, and one that researchers could make use of. “We think that exosomes could be used to further increase the effectiveness of our nanocluster contrast agent,” she said. “But looking further ahead, they could also be used to carry molecules across the blood-brain barrier–a kind of biocamouflage drug delivery. If we can do this, it could give us a new route to diagnosing and treating a range of diseases.”
Improving diagnoses is also the focus of Principal Investigator Professor Jadranka Travas-Sejdic from the University of Auckland. But rather than looking at imaging techniques, she is developing a new class of biosensors made from novel polymers that can conduct electricity. Her focus is on the development of hand-held, in-field detection systems for fast, direct electrical sensing of biological molecules.
It might sound like science-fiction, but it’s coming.Professor Jadranka Travas-Sejdic
“We’re using these sensors for DNA diagnostics, which is an important tool in identifying infectious diseases, genetic mutations, or inherited metabolic disorders,” said Professor Travas-Sejdic. “The current technology is costly and time-consuming, and we want to change that.” In collaboration with Professor David Williams, the group is currently working on producing these sensors using high-throughput printing technologies. And the next stage is to test the printed devices with complex body fluids.
Professor Travas-Sejdic and her team are funded by a 2016 Marsden grant to look further ahead too–toward stretchable and self-healing electronics for use in health monitoring. They are collaborating with microbiologists at Harvard Medical School to understand how such electronic patches could be used in, for example, repairing cardiac tissue function. “It might sound like science-fiction, but it’s coming,” she explained. “Patches that could interface directly with organs would allow us to monitor the health of vulnerable patients, or even stimulate biological tissue directly. It is an emerging new approach to healthcare.”
For our Deputy Director, Associate Professor Justin Hodgkiss from Victoria University of Wellington, nanomaterials can also make our roads and communities safer. Funded by an MBIE grant, he is developing ultrasensitive analytical devices for real-time detection of the drug methamphetamine; one for use in roadside tests, and the other for mapping substance contamination in buildings.
The devices use precisely-designed DNA aptamers, also known as synthetic antibodies, to rapidly recognise methamphetamine molecules from small, easy-to-take samples. “The existing saliva test for methamphetamine detection is expensive, slow and prone to showing false positives,” explained Associate Professor Hodgkiss. “And in order to identify the production of the drug within our housing stock, samples currently need to be collected and analysed off-site. Our new devices use nanotechnology to tackle these issues, reducing the cost of tests, and making them faster and more reliable.” Medicine has long been a collaborative pursuit. But these projects, and others like them, demonstrate the growing role that materials science will play in its future. No sci-fi nanobots needed.