Category Archives: RMIT

Diamonds improve orthopaedic implants

17 July 2019:

3D printing of titanium has made patient-specific orthopaedic implants possible, promising to dramatically improve many people’s quality of life.

But, despite the huge potential, there are still significant problems to overcome, particularly in how the implants integrate with human tissue and bone.

Associate Professor Kate Fox from RMIT University in Melbourne, an Associate Investigator with the CNBP, led the team which, in a previous study, showed that a thin film coating of diamond could provide a better surface for cells to interact.

A new paper, Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization expands on that work.

It describes how applying a nanodiamond (ND) coating on to the 3D printed titanium increased the cell density of both skin bone cells after three days of growth compared to the uncoated 3D printed titanium.

The study also showed an 88% reduction of Staphylococcus aureus – or Golden Staph – adherence to ND-coated substrates compared to those without.

This study, whose lead author is Aaquil Rifai, from RMIT, paves a way to create antifouling structures for biomedical implants.

You can read the paper here.

Journal: ACS Applied Materials & Interfaces

Publication Title:  Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization

Authors: Aaqil Rifai*, Nhiem Tran, Philipp Reineck, Aaron Elbourne, Edwin Mayes, Avik Sarker, Chaitali Dekiwadia, Elena P. Ivanova, Russell J. Crawford, Takeshi Ohshima, Brant C. Gibsonm, Andrew D. Greentree, Elena Pirogova, and Kate Fox*

Abstract:  Additively manufactured selective laser melted titanium (SLM-Ti) opens the possibility of tailored medical implants for patients. Despite orthopedic implant advancements, significant problems remain with regard to suboptimal osseointegration at the interface between the implant and the surrounding tissue. Here, we show that applying a nanodiamond (ND) coating onto SLM-Ti scaffolds provides an improved surface for mammalian cell growth while inhibiting colonization of Staphylococcus aureus bacteria. Owing to the simplicity of our methodology, the approach is suitable for coating SLM-Ti geometries. The ND coating achieved 32 and 29% increases in cell density of human dermal fibroblasts and osteoblasts, respectively, after 3 days of incubation compared with the uncoated SLM-Ti substratum. This increase in cell density complements an 88% reduction in S. aureus detected on the ND-coated SLM-Ti substrata. This study paves a way to create facile antifouling SLM-Ti structures for biomedical implants.

Key Words: nanodiamond, antifouling, 3D printing, biomaterial, implants

Nanodiamonds are a wound’s best friend

2 July 2019, By Amanda Abraham.

Band-aids and bandages are remarkable. A simple invention allows us to cover, treat and protect injuries until they have time to heal. But they come with a big drawback – the only way we can check how well the wound is healing, is by removing them.

This means that sometimes infections are detected only after they take hold, which can lead to increased recovery times and the need for additional medications and care.
Now imagine a technology that enables us to track the healing process without needing to remove the bandage.

This technology is being worked on by a group of CNBP researchers based at RMIT University who presented their research at a Physics in the Pub event held in Hawthorn last week.

The CNBP team in action at Physics in the Pub. The costume is a finger!

The team explained that by using nanodiamonds in a ‘smart dressing’, researchers are able to detect temperature changes within or surrounding a wound – a common indication of infection – without removing the bandage.

This would give doctors and nurses the ability to track the healing progress without having to remove and re-apply the dressing.

Dr Amanda Abraham, who presented alongside Qiang Sun, Daniel Stavrevski and Donbi Bai, explained that the topic was chosen because “almost everyone has experienced the pain of band-aid removal. Using nanodiamonds could save the patient further discomfort, and speed up the healing process by providing treatment only when needed.”

Physics in the Pub is an informal, light-hearted night where physicists, astronomers, theoreticians, engineers and educators share their love of science over a refreshing beverage. The event is supported by the AIP, and ARC Centres of Excellence CNBP, OzGrav, FLEET and Exciton Science.

In-body fibre optic imaging to go 3D

26 April 2019:

An advanced new method has been developed by CNBP researchers that may open the door to 3D microscopy in hard-to-reach areas of the human body.

It sees the successful miniaturization of a 3D imaging technique called ‘light field imaging’, taken to extreme new levels, making in-body application possible.

It could find significant application in diagnostic procedures called optical biopsies, where suspicious tissue is investigated during medical endoscopic procedures.

Reported in the journal ‘Science Advances’, project lead of the innovative imaging approach is Dr Antony Orth, Research Fellow at the RMIT University node of the CNBP (pictured).

The paper can be accessed below or read the media release here.

Journal: Science Advances.

Publication title: Optical fiber bundles: Ultra-slim light field imaging probes.

Authors: A. Orth, M. Ploschner, E. R. Wilson, I.S. Maksymov and B. C. Gibson.

Abstract: Optical fiber bundle microendoscopes are widely used for visualizing hard-to-reach areas of the human body. These ultrathin devices often forgo tunable focusing optics because of size constraints and are therefore limited to two-dimensional (2D) imaging modalities. Ideally, microendoscopes would record 3D information for accurate clinical and biological interpretation, without bulky optomechanical parts. Here, we demonstrate that the optical fiber bundles commonly used in microendoscopy are inherently sensitive to depth information. We use the mode structure within fiber bundle cores to extract the spatio-angular description of captured light rays—the light field—enabling digital refocusing, stereo visualization, and surface and depth mapping of microscopic scenes at the distal fiber tip. Our work opens a route for minimally invasive clinical microendoscopy using standard bare fiber bundle probes. Unlike coherent 3D multimode fiber imaging techniques, our incoherent approach is single shot and resilient to fiber bending, making it attractive for clinical adoption.

Below – Modal structure in optical fiber bundles captures light field information. Credit Antony Orth, RMIT University.

Liquid-metal nanoparticles focus UV light

29 March 2019:

Liquid-metal nanoparticles can focus ultraviolet light at the nanoscale. Read more in a publication reporting on the UV plasmonic properties of colloidal gallium-indium particles (lead author CNBP Associate Investigator Dr Philipp Reineck, RMIT University).

Journal: Scientific Reports.

Publication title: UV plasmonic properties of colloidal liquid-metal eutectic gallium-indium alloy nanoparticles.

Authors: Philipp Reineck, Yiliang Lin, Brant C. Gibson, Michael D. Dickey, Andrew D. Greentree, Ivan S. Maksymov.

Abstract: Nanoparticles made of non-noble metals such as gallium have recently attracted significant attention due to promising applications in UV plasmonics. to date, experiments have mostly focused on solid and liquid pure gallium particles immobilized on solid substrates. However, for many applications, colloidal liquid-metal nanoparticle solutions are vital. Here, we experimentally demonstrate strong UV plasmonic resonances of eutectic gallium-indium (eGaIn) liquid-metal alloy nanoparticles suspended in ethanol. We rationalise experimental results through a theoretical model based on Mie theory. our results contribute to the understanding of UV plasmon resonances in colloidal liquid-metal eGaIn nanoparticle suspensions. they will also enable further research into emerging applications of UV plasmonics in biomedical imaging, sensing, stretchable electronics, photoacoustics, and electrochemistry.

ECR Award goes to Dr Philipp Reineck

14 February 2019:

Congratulations to CNBP Associate Investigator Dr Philipp Reineck (RMIT VC Research Fellow), who has been awarded an RMIT University School of Science ‘Early Career Researcher Award’ for his outstanding research outputs and achievements in 2018.

Recognized was Philipp’s publication output. This included ten papers (with three  officially published in 2019). Also his four invited talks given at international conferences in the USA, Europe and Australia, together with his successful funding from the Australian Synchrotron to do 3D bioimaging experiments at the Spanish synchrotron.

A fantastic effort Philipp!

Below – Dr Philipp Reineck receiving his award.

 

Fraunhofer IAF visit

29 January 2019:

CNBP PhD student, Marco Capelli (RMIT) has recently undertaken a three month residency at the Fraunhofer IAF (Institute for Applied Solid State Physics) in Freiburg, Germany.  He reports on his work and collaborative activity there, focused on furthering the measurement of magnetic fields with diamond crystals.

During the months from October to December I worked with the group of Diamond Magnetometry at the Fraunhofer IAF (Institute for Applied Solid State Physics) in Freiburg, Germany.

The group leader Dr. Jan Jeske already collaborated with the CNBP in the past. His group is developing a new technique, building a laser from the fluorescence of diamond and using the enhanced signal to develop a more compact and less expensive diamond device able to perform magnetoencephalography (MEG) with high resolution and sensitivity.

At the Fraunhofer IAF I worked on our common goal of pushing further the ability of measuring magnetic fields with diamond crystals. It was a full collaborative work that put together my knowledge about magnetometry, helping optimising their existing setups and experimental procedures, with their ability to grow diamond samples with specific and tailored characteristics, searching for the best diamond to use.

I was able to compare the sample I previously used in my studies with their diamond samples and study how they differ and which are the best suited for magnetometry. This comparison is still at the beginning and our groups will further collaborate in the near future to get a full understanding of the diamond material.

The work helped me learn and better understand how diamonds can be created, how much they can be ‘customised’ and which parameters to keep in mind when choosing the appropriate diamond to use in my experiments. The students and researchers I met were keen to share their expertise and show me their advanced facilities to grow diamond. In addition it was a great learning experience to work at the institute itself. As the institute is more focused with practical applications and connecting with industry, it was personally interesting to see the differing kinds of management and organisational structures in place there.

Below: Marco (third left) with the  Diamond Magnetometry team.

Not all fluorescent nanodiamonds are created equal

28 January 2019:

Hundreds of individual tiny fluorescent diamond particles have been imaged and characterized by CNBP researchers, reported in the journal ‘Particle & Particle Systems Characterization’.

Fluorescent nanodiamonds (FNDs) are vital to many emerging nanotechnological applications, from bioimaging and sensing to quantum nanophotonics.

The study identifies opportunities to improve the properties of single fluorescent nanodiamonds, to develop a better understanding of their underlying physical mechanisms and to advance current nanofabrication technologies.

Lead author on the paper is CNBP Associate Investigator Dr Philipp Reineck at RMIT University.

Journal: Particle & Particle Systems Characterization.

Publication title:  Not All Fluorescent Nanodiamonds Are Created Equal: A Comparative Study.

Authors: Philipp Reineck; Leevan Fremiot Trindade, Jan Havlik, Jan Stursa, Ashleigh Heffernan, Aaron Elbourne, Antony Orth, Marco Capelli, Petr Cigler, David A. Simpson, Brant C. Gibson.

Abstract: Fluorescent nanodiamonds (FNDs) are vital to many emerging nanotechnological applications, from bioimaging and sensing to quantum nanophotonics. Yet, understanding and engineering the properties of fluorescent defects in nanodiamonds remain challenging. The most comprehensive study to date is presented, of the optical and physical properties of five different nanodiamond samples, in which fluorescent nitrogen‐vacancy (NV) centers are created using different fabrication techniques. The FNDs’ fluorescence spectra, lifetime, and spin relaxation time (T1) are investigated via single‐particle confocal fluorescence microscopy and in ensemble measurements in solution (T1 excepted). Particle sizes and shapes are determined using scanning electron microscopy and correlated with the optical results. Statistical tests are used to explore correlations between the properties of individual particles and also analyze average results to directly compare different fabrication techniques. Spectral unmixing is used to quantify the relative NV charge‐state (NV− and NV0) contributions to the overall fluorescence. A strong variation is found and quantified in the properties of individual particles within all analyzed samples and significant differences between the different particle types. This study is an important contribution toward understanding the properties of NV centers in nanodiamonds. It motivates new approaches to the improved engineering of NV‐containing nanodiamonds for future applications.

CNBP presents at IETS Conference

23 January 2019:

Prof Brant Gibson and Prof Jeremy Thompson (both CNBP Chief Investigators) have attended (and presented) at the  International Embryo Technology Society (IETS) conference held in New Orleans, January 20– 23, 2019.

A lunch presentation session sponsored by CNBP, provided both representatives with the opportunity to talk about CNBP as well as to provide information on the organisation’s latest research and activity, taking place in the imaging and reproduction spaces.

Areas covered included: research on improving in vitro embryo production (IVF) systems; the development of a purpose-built, multi-function, micron-scale embryo ‘housing’ device created via unique 3D-printing technology; discussion on advanced hyperspectral imaging techniques; and the development by CNBP researchers of a clip-on device to enhance the magnification of a mobile phone’s existing optics, enabling bull semen analysis.

“The CNBP presentation went even better than I was expecting and we had over 40 people in attendance,” said Prof Gibson.

“Everyone enjoyed the lunch and there were plenty of questions and discussion from key people in the field, during and after our presentations. ”

“Hopefully this will spark some future collaborations both from a research and translation point of view,” Prof Gibson concluded.

The IETS Conference is the preeminent meeting in animal biotechnology, covering a broad area from embryo production and transfer techniques to cloning and transgenesis. The conference attracted more than 600 attendees from all over the world.

Below: A/Prof Jeremy Thompson discusses use of photonic probes in the reproduction space.

Super-resolution volumetric imaging

11 December 2018:

The Australian Research Council (ARC) has announced funding for a super-resolution imaging facility that will be the first of its kind in Australia.

The facility brings together a consortium of multidisciplinary researchers from leading Australian Universities, Institutes and Research Centres (including CNBP) to develop new capacities for materials science, photonics devices, engineering, and neuroscience, microbial and cardiovascular research.

At its core the A$3.0m ARC LIEF project will enable scientists to study the inner workings of cells in their native environment. This represents a step change from currently imaging isolated 2D cells cultured in a petri dish to future research that will reveal subcellular structures and cell-to-cell communications in 3D tissue in real time.

The National Volumetric Imaging Platform, as it is known, will be installed, maintained and operated by the Institute for Biomedical Materials and Devices (IBMD) at the University of Technology Sydney (UTS) and the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) at RMIT University in Melbourne. This project is scheduled to be completed in late 2019.

UTS Professor Dayong Jin, Lead Chief Investigator of the project, said that the facility will give scientists a “new way to decode the complexities of life science machinery.”

“High-resolution imaging of the large volume of single cells and functional navigation of their interactions will allow researchers to drop into a ‘street view’ and observe the details of intercellular ‘live traffic’,” he said.

Prof Brant Gibson, Co-Deputy Director and RMIT node director of CNBP said, “I am very excited to lead the RMIT University node of the National Volumetric Imaging Facility and to work in collaboration with Jin Dayong, the UTS node and all of our collaborative institutional partners. This facility will enable us to image deeper within biological samples than we ever been able to before, with nanoscale resolution and extraordinary bandwidth stretching from the near-UV (400nm) well into the infrared (1650nm) spectrum.”

Prof Mark Hutchison, Professor at the Adelaide Medical School and Director of the CNBP at the University of Adelaide said, “This is an exciting development of advanced imaging infrastructure capacity that will allow a convergence of scientists from across the country to gain an unprecedented level of molecular insights into the complex systems and arrangement of cells in biologically relevant complex 3 dimensional environments.”

Participating Organisations include: Universities: University of Technology Sydney, RMIT University, University of Wollongong, University of Sydney, The University of Queensland, The University of New South Wales, Macquarie University, The University of Adelaide.

Institutes and Centres: Institute for Biomedical and Materials Devices, ARC Research Hub for Integrated Device for End-user Analysis at Low-levels, Institute for Molecular Horizons, the Heart Research Institute, ithree Institute, Centre for Translational Neuroscience, Australian Centre for Ecogenomics, ARC Centre of Excellence for Nanoscale BioPhotonics.

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Optimising the creation of NV centres in diamond

24 November 2018:

An improved method to convert nitrogen to nitrogen-vacancy (NV) color centers in diamond has been reported by CNBP researchers in a paper published in the journal Carbon. Lead author of the paper was CNBP student Marco Capelli (pictured).

Journal: Carbon.

Publication title: Increased nitrogen-vacancy centre creation yield in diamond through electron beam irradiation at high temperature.

Authors: M. Capelli, A.H. Heffernan, T. Ohshima, H. Abe, J. Jeske, A. Hope, A.D. Greentree, P. Reineck, B.C. Gibson.

Abstract: The nitrogen-vacancy (NV) centre is a fluorescent defect in diamond that is of critical importance for applications from ensemble sensing to biolabelling. Hence, understanding and optimising the creation of NV centres in diamond is vital for technological progress in these areas. We demonstrate that simultaneous
electron irradiation and annealing of a high-pressure high-temperature diamond sample increases the NV centre creation efficiency from substitutional nitrogen defects by up to 117 % with respect to a sample where the processes are carried out consecutively, but using the same process parameters. This increase in fluorescence is supported by visible and infrared absorption spectroscopy experiments. Our results pave the way for a more efficient creation of NV centres in diamond as well as higher overall NV densities in the future.