Large bone defects arising from trauma, infection, or tumour resection present a major challenge in orthopaedic medicine, especially for bones that are loadbearing.
To solve this problem, University of Sydney School of Biomedical Engineering academic and Director of the ARC Centre for Innovative BioEngineering, Professor Hala Zreiqat developed and patented a class of synthetic bone substitutes that are simultaneously bioactive, strong and resorbable.
These 3D-printable synthetic biomaterials are not only capable of healing large bone defects, but can also withstand the stresses and strains of weight-bearing parts of the body like the spine.
“Therapeutic options for many orthopaedic injuries have improved considerably over the years, yet the repair of extensive bone damage has proved an intractable problem,” said Professor Zreiqat.
“The overarching goal of our endeavour has been to use innovative approaches and technologies to produce clinically relevant synthetic scaffold materials for the treatment of large bone defects that cannot heal without intervention.”
This innovation will improve people’s health and their lives, while reducing the overall resources required for these kinds of surgeries and the risks involved.
Current treatments using bone autografts have serious limitations.
In response to this challenge, Zreiqat and her team developed novel bioactive ceramics to be used in the bone implants, which is fabricated using scaffolds with high porosity (80 percent) and interconnectivity (100 percent) while maintaining strength and toughness.
Two of the developed materials, Gahnite and Baghdadite, are expected to transform the future of surgery for bone defects. In the case of Gahnite, once the patient’s real bone has grown back, the implant vanishes, having been absorbed by the body.
A significant amount of carbon is emitted when crude oil is refined to produce products like shampoo, oil, medicine, gasoline or diesel, all of which contain hydrocarbons.
Nevertheless, industrial sectors rely so heavily on these compounds that hydrocarbon is now a $1.5 trillion industry.
To speed up the reﬁnement process, oil reﬁneries currently use silica-alumina materials, such as crystalline zeolites and amorphous silica-alumina, as chemical catalysts to crack the crude oil or bio-oil.
Now, University of Sydney Professor Jun Huang has produced a new amorphous silica-alumina catalyst with stronger acidity than any other silica-alumina material created before.
"The unique acidity of the catalyst used allows us to reduce the amount of coke left behind in hydrocarbon production and further decrease carbon dioxide emissions from coke-burning during oil reﬁnement," said Professor Huang, from the School of Chemical and Biomolecular Engineering.
The implications of this research are highly significant for many industries and highlight the potential for a catalyst industry in Australia.
Professor Huang's work has the potential to not only make the fossil fuel industry greener, but also to develop the biomass industry for sustainable alternatives to hydrocarbon production.
If this new catalyst was to be adopted by the entire oil refinery industry, a reduction of more than 20 per cent in carbon dioxide emissions could be achieved during the oil reﬁnement process – the equivalent of twice Australia’s crude oil consumption of more than two million barrels of oil per day.
People living with profound visual impairments must rely on sensory substitution – using other senses in place of sight to understand the world.
For these people tactile information is particularly important, but the majority of tactile interfaces are unpopular because they tend to be bulky and have limited bandwidth due to mechanical impedance – a measure of how much a structure resists motion.
To address this, University of Sydney School of Computer Science lecturer Dr Anusha Withana leads a project called Tacttoo, which involves the creation of a thin, flexible and disposable electronic tattoo that could generate a high-resolution tactile sensation on the skin.
Tacttoo directly interfaces with nerve fibres to generate an electro-tactile sensation, and, at under 35 μm in thickness, it is thinner than any other tactile interface on the market.
Tacttoo works by combining multiple functional inks with different mechanical properties to create a thin and stretchable structure that can be used as an electronic tattoo.
Dr Withana’s team has also engineered tiny spring mechanisms so the device can conform with microstructures of the skin surface.
As a result, users cannot feel it on their skin, meaning the device works as an interface that can be felt through. The spring structures can withstand the stresses of a normal eight-hour working day, while the Tacttoo is worn on a user’s fingertip in an office environment.
That means it can be used as a braille replacement for visually impaired people to explore graphics such as maps, online images and videos, which ensures visually impaired people will no longer have to rely on abstract and insufficient details conveyed by text-to-speech technology.
Graphical information can be critically important when it comes to education, where visually impaired students’ needs to learn geometric shapes, spatial relationships, dimensions and graphs. Therefore, creating effective, affordable and real-time visual to tactile translation methods addresses a significant problem in the society.
The project was funded by the European Union as part of a European Research Council project on interactive skin.
A truly immersive virtual reality experience is on the horizon, according to Dr Shuaiwen Song from the School of Computer Science.
He believes consumers in the coming era of technological change will want access to a commercial virtual reality (VR) product that can lift them to an alternate fantasy dimension: a true immersive experience without mobility restriction and periodic motion anomalies.
This product is ‘planet-scale VR’, a concept that would permit users around the world, regardless of their hardware and network conditions, to use this technology.
For this to become reality, users will require exceptional visual quality-of-experience from an edge-powered untethered mobile-rendered VR head-mounted display.
Due to the quality-of-experience constraints on mobile VR’s responsiveness, frame rate and power consumption, neither local edge-processing nor cloud rendering reaches the real-time requirements for an immersive VR environment.
“Inspired by the concept of foveated computing, a technique that reduces image quality to reduce rendering workload, my team has innovated a software-hardware co-design for a lightweight and fast AI-based cloud-edge collaborated VR simulation prototype to enable this revolutionary technology,” said Dr Song.
“We hope this innovation can help commercial partners to develop such products in a short period of time that considers mobile hardware performance, network evolution as well as cloud server design.”
Song expects the innovation to have a signifi cant impact on the entire world. He sees a scenario where VR service occurs indiscriminately across planet-sized scale.
Australia’s ageing population has led to a rising incidence of osteoporosis-related bone fractures, bone cancers and joint replacements.
Orthopaedic surgeries involving implants have increased, but many of these surgeries result in poor outcomes, because their success relies on ﬁrm bone bonding in implants.
Dr Behnam Akhavan, from the School of Biomedical Engineering, has developed a highly robust plasma coating that mitigates such issues by mimicking the surrounding tissue, increasing the likelihood of an implant fusing to the host bone, thus reducing the chance of rejection or infection.
The plasma coating works by “shielding” an implant to trick the body into accepting it as a biologically friendly object rather than an invasion.
If this technology does deliver on its promise, then there is the potential to eliminate thousands of surgeries a year, mostly undertaken by patients who have significant other risks involved.
The fully organic coating enables the strong coupling of biomolecule-like proteins on the implant surface, which then facilitate the overgrowth of bone-producing cells on the implant once inserted in the body, allowing it to ﬁrmly attach to bone tissue rather than being colonised by bacteria.
A key challenge in realising this innovation was that the coating had to be stable enough to survive severe deformation during surgery, followed by long-term immersion in corrosive body ﬂuids. The fabrication of robust organic coatings on metals has been a long-standing issue in surface engineering.
Using fundamental research on plasma-surface interactions, Akhavan mitigated this problem by creating robust, ion-stitched interfaces between the coating and implant surface. These coatings can remain intact for long durations, even if they are scratched during surgery.
Dr Akhavan's research opens up the possibility of fabricating a new generation of anti-infection biomedical devices with improved tissue-implant integration, beneﬁting the growing numbers of patients relying on implants.