Harnessing light for a healthcare revolution

Photo: Vanessa Valenzuela Davie

Photo: Vanessa Valenzuela Davie

In summary: 
  • Professor Dayong Jin is director of a $3.7 million ARC Industrial Transformation Hub whose objective is to develop portable diagnostic devices with superior detection capabilities.
  • Professor Jin was part of an Australian research team that developed a technology known as Super Dots, which won a prestigious Eureka Prize in 2015.

Professor Dayong Jin envisions a future where portable diagnostic devices will be as ubiquitous as smartphones, where scientists can peer inside individual cells, and where diseases can be detected before they infect our bodies.

A pioneer in the emerging field of nanoscale biophotonics at the University of Technology Sydney, it’s a future Jin is working hard to create.

“The nanoscale is really the fundamental level on which biological molecules operate,” he says. “It’s the scale of the original disease.”

Jin engineers functional nanoparticles – invisible to the naked eye – which harness light to probe our cells, detect diseases and deliver drugs in perfectly measured doses.

Transforming the biomedical industry

Jin was recently named the Director of a new A$3.7 million Australian Research Council Industrial Transformation Hub. The hub’s objective is to develop portable diagnostic devices with vastly improved detection capabilities.

These easy-to-use devices, which incorporate nanomaterials and photonic technologies developed by Jin and his colleagues from the University of Technology Sydney and the University of South Australia, can analyse incredibly small samples of substances including breath, saliva, urine and blood, to find markers of disease.

Jin says these point-of-care technologies will ease the burden on hospitals and align with the demands of consumers: real-time health monitoring, and faster treatment options.

“In the near future, prostate cancer patients who have gone into remission will have a handheld device at home to analyse their urine samples,” he says. “It will be able to tell them whether their cancer is recurring.”

The hub is also working with industry partners to develop an improved roadside breath-testing device for police forces to detect traces of illicit drugs.

Over its five-year lifespan, Jin expects the hub to generate a number of new portable diagnostic devices, which can be tailored to specific applications to detect everything from cancers to infectious diseases and environmental pollutants.

Super Dots diagnose diseases inside the body

Jin is also helping improve disease diagnosis from inside the body itself.

Cancers and infectious disease outbreaks all originate from a single cell, he says.

“The current challenge is that we don’t have a method to find this very rare cell from the earliest stage.”

Jin was part of an Australian research team that developed a technology known as Super Dots, which won a prestigious Eureka Prize in 2015. These nanoparticles can find a needle in a haystack, detecting individual diseased cells from a population of millions.

The particles are made from a nanocrystal material that can absorb invisible infrared light and emit higher energy, visible light, says Jin.

Once the nanoparticle has found the target cell inside the body, or a blood sample, it can be stimulated by researchers with a harmless, skin-penetrating infrared light.

The dot then emits a visible flash, which causes the diseased cell to light up.

“It’s like you have the diseased cell glowing in the darkness,” says Jin. “This allows you to achieve the ultimate detection sensitivity.”

Beyond medicine, Super Dots can be encoded with “secret signatures” and used for the anti-counterfeiting of passports, banknotes and drug labels, says Jin.

There are also applications for more efficient solar cells and 3D display screens.

Breaching the blood-brain barrier

Jin is hopeful that another class of his nanoparticles will serve as a versatile drug delivery vehicle, capable of breaching the protective blood-brain barrier.

Delivering drugs to individual neurons in the brain is a “holy grail problem” in neurological research, says Jin.

“There are many drugs already developed to treat Alzheimer’s and Parkinson’s quite effectively outside the body,” he says. “But the blood-brain barrier prevents more than 99 per cent of drugs from accessing the brain from the blood circulation system.”

Jin and his colleagues have created a library of 800 types of nanoscale drug carriers with specific shapes, sizes and surface functionality. Importantly, they have developed a process to replicate these carriers exactly, according to any design.

“We’ve solved the problem in terms of developing the material,” he says.

“If the tailored drug carrier can tell the blood-brain barrier that the carriers are the friend and not the enemy… we can open a gate into the brain.”

Super-resolution microscopy breakthrough

Jin’s research has led to a recent breakthrough in the field of microscopy.

With colleagues at Georgia Institute of Technology in the US and Peking University in China, Jin has developed a simple but highly effective way to see individual cells in 3D – overcoming a major barrier. Instead of growing cells on transparent glass slides, the team grew their cells on specialised mirrors. As reflected light passed through the cell while being viewed under a super-resolution microscope, researchers could see new structures in exquisite detail. 

“This simple technology is allowing us to see the details of cells that have never been seen before,” says Jin. “We can see the tiny little hole on the cell nucleus’ membrane – that hole is the entrance and exit for single molecules.

“When the cell wants to express a signal, or send a message outside the cell, this is the gateway – and we now have the tool to see what that looks like.”

By understanding how cells behave, communicate and how diseases arise inside them, researchers can develop more effective treatments.

Jin and Professor Peng Xi from Peking University hold a patent for their invention, and Jin says they are currently exploring opportunities to commercialise the technology with leading imaging companies such as Olympus and German firm Leica.

Multiculturalism trumps geography for Australia

It was love that brought Jin to Australia from his home in north-eastern China, near the border with Inner Mongolia. His future wife, Lisa Li, came to Sydney to study accounting in 2002, and he followed.

Jin ended up at Macquarie University in the laboratory of Dr Jim Piper, a renowned expert in lasers, optics and photonics. Under his guidance, Jin developed a system to detect trace amounts of pathogens in water.

Jin says the postgraduate scholarship in Australia was more comprehensive and generous than what was offered to his Chinese peers who chose to study in the US.

Jin says he and his family had planned on returning to China or finding a postdoctoral position in the US after his PhD, but ultimately decided to stay in Australia.

He says the decision has been good for his career: “Geographically, Australia looks like it’s isolated,” he says. “But we are actually well connected.

“The Australian research community is very multicultural, and these ‘soft connections’ have created a lot of opportunities for my research collaborations.”

Jin says multidisciplinary knowledge and collaboration is vital to realising the healthcare future he envisions – and going even further beyond.

In addition to his many breakthroughs, one of the prospects Jin is most excited about is that of truly personalised medicines.

At present, people with the same diseases are all treated with the same drugs, which might be totally ineffective for a proportion of the population, says Jin.

“But future medicines will have a tool to decode the unique molecular signature of a patient,” he says.

It means when two people have the same disease, they could be treated remarkably differently – with dramatically improved outcomes.

This is where we’re heading, he says.

Source: First published on australiaunlimited.com. Author: Myles Gough. Licensed from the Commonwealth of Australia under a Creative Commons Attribution 4.0 Australia Licence. The Commonwealth of Australia does not necessarily endorse the content of this publication.

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