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Science/Tech See other Science/Tech Articles Title: Aussie scientists working on bionic eye In a new approach to restoring sight, Swinburne researchers are focusing on gold nanoparticles and laser light The research program incorporates aspects of physics, engineering and biomedical science The new bionic eye model would ‘stimulate’ the nervous system People cannot see nanoparticles, but nanoparticles may one day help people to see. Microscopic gold nanoparticles fixed to optical nerves and assembled to respond to different laser light wavelengths could become the key to bionic vision – to restoring sight using a vision prosthesis or ‘bionic eye’. This laser stimulation of nerves, particularly optic nerves, is the focus of an innovative new research stream at Swinburne University of Technology, which has joined the global quest to develop a vision prosthesis – much like the cochlear implant for restoring hearing. Swinburne is taking a novel approach, looking for a non-contact method of stimulating nerves. Researchers at the Hawthorn campus have begun exploring the use of laser light, rather than the direct electrical stimulation techniques that have become the conventional approach. The initial research is being driven by PhD student Chiara Paviolo under the supervision of Professor Sally McArthur and Dr Paul Stoddart, whose respective biointerface engineering and biomedical engineering groups are leaders in combining physical and biological science with engineering to develop new ways of detecting and stimulating events that occur in our bodies. Professor David Crewther of the Brain and Psychological Sciences Research Centre at Swinburne is providing the visual neuroscience expertise for the team. There is a lot of work ahead of us, but the potential rewards in terms of progressing medical science and helping people recover from extreme trauma, including blindness, are immense.” - Professor Sally McArthur Professor McArthur says the bionic eye research has emerged from Swinburne's applied optics group, which is using gold nanoparticles to amplify laser light. “This is an important initial step because it means we only need a very low intensity laser source to generate the right amount of heat required to elicit a response from the nerve cells without damaging them. “From a functional perspective, this means we can use an external source of stimulation (for example, a tiny laser device fitted within a pair of spectacles) rather than the conventional electrode approach.” Swinburne’s ‘bionic eye’ research is in its early stages, but for some this is the most exciting time. It is when the initial creative idea or insight – in this case, the use of optical heating to stimulate nerve fibres via a nanoparticle interface – is being challenged, tested and given shape. Stimulating individual nerves for clarity Ms Paviolo says that one of the strongest aspects of this new concept is the potential for light to deliver far more precise nerve cell stimulation than electrodes. “Electrodes need an electrical current and so they consequently stimulate a group of nerves. Light, however, allows us to target individual nerves and this should mean more accurate communication of optical signals – an essential outcome if the information delivered to the brain via a prosthesis is to mean anything useful in terms of shapes, colours, dimensions. You don’t just want optical ‘noise’.” The initial goal is to successfully bond the nanoparticles to the nerve and then achieve a response to light heat. Professor McArthur explains: “We first have to make sure the nanoparticles stay on the outside of the cell and aren’t absorbed by the body. We have to create a Velcro-like system in which the particles stick to the outside of the cell. And this brings into the project another whole field of science – tissue engineering.” Gold nanoparticles are being used because gold is inert, biocompatible and has plasmonic (light-responsive) properties. The gold nanoparticles can also be fabricated to respond to different wavelengths, making the interface controllable. “We are fortunate to have been able to draw on the work of Dr Stoddart, who has been central to Swinburne’s research into the laser light–nanoparticle interface. He is showing how the metal nanoparticles concentrate the light and amplify it,” Professor McArthur says. The nanoparticles used in the project are being produced at Swinburne by another PhD student, Jiawey Yong, who has been charged with developing nanoparticles that are thermally stable. This is another of the many challenges facing the researchers: while on one hand heat is necessary, it also has to be limited to avoid damaging cells. Laser heat has long been used in medicine to deliberately kill tissue, but in this instance the opposite result is sought. “The work ahead of us is to determine the type and strength of laser light needed to penetrate the eye and other tissue, and then, on reaching the nanoparticles that coat the nerve cells, to create a heat stimulant,” Professor McArthur says. “There’s still a lot of fundamental biology to work on, to also find out, for example, just how the heat stimulates the nerves; does it do so directly or because it elicits a biochemical response? It is this interface of the physical sciences with biology that is so fascinating and so full of potential.” To measure and control the heat, the Swinburne team has almost finished building a molecular thermal sensor to measure how much heat is produced, so they can then work out, if necessary, how to control it. Ambition for bionic glasses fuels pioneering science It’s a good example of pioneering science. Not only does the team determine what each step must be, but it is also ready to measure the consequences of each step. A multitude of tiny steps, sometimes forwards, sometimes backwards, must be taken before the day, perhaps well into the future, when the world awakens to the news that a bionic eye (or bionic glasses) is no longer the stuff of science fiction, but a fully tested, safe reality. The fact that this is even now a serious research project reflects also the confluence of other technologies – the arrival of nanotechnology that allows materials to be fabricated (given shape and function) on an atomic scale. The Swinburne team’s ultimate ambition for its technology is a prosthesis that in the first instance will restore vision to people who have lost their sight through retinitis pigmentosis or macular degeneration. “With these diseases the nerve is still alive, making it a strong candidate for a prosthesis,” Ms Paviolo explains. It fits well with her personal motivation for pursuing a career in research: “I’ve always been interested in science, especially in the biomedical area, because of the capacity that new knowledge has to help people. There are two incentives: one is to increase knowledge, but then you also want to be able to use that knowledge to help people.” Ms Paviolo initially graduated with a master degree in biomedical engineering from the Polytechnic of Turin, Italy, then undertook research into stem cells at Lausanne, Switzerland, before deciding to travel – a path that brought her to Melbourne, and Swinburne. She was fascinated by the new approach being proposed to stimulate nerves using non-invasive bionics – light – and from a pragmatic research perspective she found the facilities, international links and presence of world-leading expertise a strong reason to stay at Swinburne and get involved. Ms Paviolo started the project – Optical Stimulation of Nerves: Towards Non-invasive Bionics – in February 2010 under the supervision of Professor McArthur and Dr Stoddart. Technical support is now also being provided by Alex Thompson and Dr Scott Wade at Swinburne’s biointerface and biomedical engineering groups. Another PhD student, Will Brown, co-supervised by Dr Andrew Clayton with Professor McArthur and Dr Stoddart, is directing his studies into the cellular mechanism that responds to light stimulation. Ms Paviolo will spend eight months with Professor John Haycock in Sheffield in the UK where artificial tissue (nerve cells grown in vitro) will be used to explore nanoparticle behaviour in animal tissue. This is necessary to achieve Professor McArthur’s ‘Velcro’ effect. Ms Paviolo is using a top-up scholarship from Nanoventures Australia to fund this component of the research. The development of the actual laser technologies to be used as the light source is being done in collaboration with OptoTech Pty Ltd, Melbourne-based specialists in laser systems development. Global interest Ms Paviolo says international interest is already building in the Swinburne project because, among the many international research teams working to develop a bionic eye, the concept of using light stimulation combined with nanotechnology is novel. “We are pushing this idea as far as we can, and so there is strong interest in what we can achieve.” Professor McArthur says the technology has, in principle, the potential to help repair other forms of nerve trauma. “For example, microsurgery can now rejoin a severed nerve, but not when too much tissue is missing. Using nanoparticles and tissue engineering we believe we will be able to build molecular constructs that are able to fill the gap between severed nerve ends and ‘guide’ the two nerve ends into contact. “However, the first task is to demonstrate proof of concept. There is a lot of work ahead of us, but the potential rewards in terms of progressing medical science and helping people recover from extreme trauma, including blindness, are immense.” Editor's Note: A story provided by Swinburne Magazine. This article is under copyright; permission must be sought from Swinburne Magazine to reproduce it.
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#1. To: Tatarewicz (#0)
It fits well with her personal motivation for pursuing a career in research: “I’ve always been interested in science, especially in the biomedical area, because of the capacity that new knowledge has to help people. There are two incentives: one is to increase knowledge, but then you also want to be able to use that knowledge to help people.” A beautiful person. A true humanitarian. She must be killed before she helps someone. /s
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