Category Archives: UA

Ruthenium-based sensor detects nitric oxide

8 February 2019:

In a new publication, a responsive Ruthenium-based luminescence sensor was employed as a molecular probe for detecting nitric oxide (NO). The research suggests potential clinical utility for the measurement of soluble NO in the circulation system and possibly tissue. Lead authors of this paper are CNBP’s Dr Achini Vidanapathirana and Benjamin Pullen (both based at SAHMRI).

Journal: Scientific Reports.

Publication title:  A Novel Ruthenium-based Molecular Sensor to Detect Endothelial Nitric Oxide.

Authors: Achini K. Vidanapathirana, Benjamin J. Pullen, Run Zhang, MyNgan Duong, Jarrad M.Goyne, Xiaozhou Zhang, Claudine S. Bonder, Andrew D.Abell, Christina A. Bursill, Stephen J. Nicholls & Peter J. Psaltis.

Abstract: Nitric oxide (NO) is a key regulator of endothelial cell and vascular function. The direct measurement of NO is challenging due to its short half-life, and as such surrogate measurements are typically used to approximate its relative concentrations. Here we demonstrate that ruthenium-based [Ru(bpy)2(dabpy)]2+ is a potent sensor for NO in its irreversible, NO-bound active form, [Ru(bpy)2(T-bpy)]2+. Using spectrophotometry we established the sensor’s ability to detect and measure soluble NO in a concentration-dependent manner in cell-free media. Endothelial cells cultured with acetylcholine or hydrogen peroxide to induce endogenous NO production showed modest increases of 7.3 ± 7.1% and 36.3 ± 25.0% respectively in fluorescence signal from baseline state, while addition of exogenous NO increased their fluorescence by 5.2-fold. The changes in fluorescence signal were proportionate and comparable against conventional NO assays. Rabbit blood samples immediately exposed to [Ru(bpy)2(dabpy)]2+ displayed 8-fold higher mean fluorescence, relative to blood without sensor. Approximately 14% of the observed signal was NO/NO adduct-specific. Optimal readings were obtained when sensor was added to freshly collected blood, remaining stable during subsequent freeze-thaw cycles. Clinical studies are now required to test the utility of [Ru(bpy)2(dabpy)]2+ as a sensor to detect changes in NO from human blood samples in cardiovascular health and disease.

Gold nanomembranes with nanoholes

1 February 2019:

In a break-through in the field of nano membrane related research, CNBP alumni scientist Dr Peipei Jia and colleagues report on the development of large-area freestanding gold nanomembranes with nanohole arrays fabricated using a replication-releasing procedure. More information available below!

Journal: Materials Horizons.

Publication title:  Large-area Freestanding Gold Nanomembranes with Nanoholes.

Authors: Peipei Jia, Kamil Zuber, Qiuquan Guo, Brant C. Gibson, Jun Yang and Heike Ebendorff-Heidepriem.

Abstract: Thin metal films with nanohole arrays have opened up new opportunities in applications ranging from plasmonics to optoelectronics. However, their dependence on substrates limits not only their performance but also other application possibilities. A key challenge to overcome this limitation is to make these nanostructured films substrate-free. Here we report large-area freestanding gold nanomembranes with nanohole arrays fabricated using a replication-releasing procedure. The structures maintain spatial uniformity and pristine quality after release across the entire membrane up to 75 cm2 in area and as thin as 50 nm. The freestanding nanomembranes show significantly enhanced optical transmission and effective field extension compared to the same nanomembranes on substrates. A plasmonic coupling resonance with a 2.7 nm linewidth achieves a record figure-of-merit of 240 for refractive index sensing. The gold nanomembranes can be geometrically converted to 3D microstructures by ion-irradiation-based kirigami technique. The transformed micro-objects can be precisely controlled via geometry design and strategic cutting. Furthermore, we find the presence of nanoholes can significantly change the in-plane modulus of the gold nanomembranes. Finally, the freestanding gold nanomembranes can be transferred to non-planar substrates, enabling their future integration with advanced optical and electronic systems for emerging applications.

Tailoring third-harmonic generation

25 January 2019:

CNBP Associate Investigator Dr Stephen C. Warren-Smith is lead author on a new publication that has demonstrated multi-wavelength third-harmonic generation from an exposed-core microstructured optical fibre.

Journal: Optics Letters.

Publication title: Tunable multi-wavelength third-harmonic generation using exposed-core microstructured optical fiber.

Authors: Stephen C. Warren-Smith, Kay Schaarschmidt, Mario Chemnitz, Erik P. Schartner, Henrik Schneidewind, Heike Ebendorff-Heidepriem, and Markus A. Schmidt.

Abstract: We demonstrate that exposed-core microstructured optical fibers offer multiple degrees of freedom for tailoring third-harmonic generation through the core diameter, input polarization, and nanofilm deposition. Varying these parameters allows control of the phase-matching position between an infrared pump wavelength and the generated visible wavelengths. In this Letter, we show how increasing the core diameter over previous experiments (2.57 μm compared to 1.85 μm) allows the generation of multiple wavelengths, which can be further controlled by rotating the input pump polarization and the deposition of dielectric nanofilms. This can lead to highly tailorable light sources for applications such as spectroscopy or nonlinear microscopy.

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.

New researcher joins Adelaide team

22 January 2019:

CNBP welcomes its newest research recruit to Adelaide University, Dr Erin Smith.

Dr Smith will be working with CNBP Chief Investigator Prof. Andrew Abell and his group to explore the synthesis of photoswitchable inhibitors.

Previously, Dr Smith completed a PhD in synthetic chemistry at Curtin University in collaboration with Epichem. She was investigating new biosynthesis inhibitors as a new drug lead for the treatment of Chagas disease.

She has also worked as a postdoctoral researcher at Bayer in Germany. There she was employed as part of the Herbicide Innovation Partnership between Bayer and GRDC (Grains Research and Development Corporation) investigating the synthesis of compounds as potential herbicides for Australian agriculture.

A big welcome to the CNBP team Erin!

Helping make brain surgery safer

19 December 2018:

Researchers from CNBP and the Institute for Photonics and Advanced Sensing, together with Sir Charles Gairdner Hospital and University of Western Australia collaborators, have demonstrated  the potential of an ‘imaging needle’ for reducing the risk of dangerous brain bleeds in patients undergoing brain biopsy. In the journal Science Advances, the researchers describe how a tiny imaging needle can detect blood vessels with a very high degree of accuracy (91.2% sensitivity and 97.7% specificity). Pictured is corresponding author of the paper CNBP Investigator Prof Robert McLaughlin, University of Adelaide.

Journal: Science Advances.

Publication title: Intraoperative detection of blood vessels with an imaging needle during neurosurgery in humans.

Authors: Hari Ramakonar, Bryden C. Quirk, Rodney W. Kirk, Jiawen Li, Angela Jacques, Christopher R. P. Lind and Robert A. McLaughlin.

Abstract: Intracranial hemorrhage can be a devastating complication associated with needle biopsies of the brain. Hemorrhage can occur to vessels located adjacent to the biopsy needle as tissue is aspirated into the needle and removed. No intraoperative technology exists to reliably identify blood vessels that are at risk of damage. To address this problem, we developed an “imaging needle” that can visualize nearby blood vessels in real time. The imaging needle contains a miniaturized optical coherence tomography probe that allows differentiation of blood flow and tissue. In 11 patients, we were able to intraoperatively detect blood vessels (diameter, >500 μm) with a sensitivity of 91.2% and a specificity of 97.7%. This is the first reported use of an optical coherence tomography needle probe in human brain in vivo. These results suggest that imaging needles may serve as a valuable tool in a range of neurosurgical needle interventions.

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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Soft-glass imaging microstructured optical fiber

10 December 2018:

A proof-of-concept fabrication of a soft-glass imaging microstructured optical fiber has been demonstrated by CNBP scientists in a new research paper published in the journal Optics Express. Lead author of the paper is Dr Stephen C. Warren-Smith, CNBP Associate Investigator at the University of Adelaide who notes that it is envisaged that the glass-based optical fibers will find potential use in applications such as in-vivo white-light and spectroscopic imaging.

Journal: Optics Express.

Publication title: Soft-glass imaging microstructured optical fibers.

Authors: Stephen C. Warren-Smith, Alastair Dowler, and Heike Ebendorff-Heidepriem.

Abstract: We demonstrate the fabrication of multi-core (imaging) microstructured optical fiber via soft-glass preform extrusion through a 3D printed titanium die. The combination of extrusion through 3D printed dies and structured element (capillary) stacking allows for unprecedented control of the optical fiber geometry. We have exploited this to demonstrate a 100 pixel rectangular array imaging microstructured fiber. Due to the high refractive index of the glass used (n = 1.62), such a fiber can theoretically have a pixel pitch as small as 1.8 µm. This opens opportunities for ultra-small, high-resolution imaging fibers fabricated from diverse glass types.

Modulation of the nano-environment

15 November 2018:

A new CNBP research publication (lead author Dr Roman Kostecki, University of Adelaide) describes how molecular interactions can be modulated by defining the local nano-environment to give a specific chemical outcome.

Journal: ACS Applied Materials and Interfaces.

Publication title: Control of Molecular Recognition via Modulation of the Nanoenvironment.

Authors: Roman Kostecki, Sabrina Heng, Adrian M. Mak, Heike Ebendorff-Heidepriem, Tanya M. Monro, and Andrew D. Abell.

Abstract: Many biological processes are driven by the interaction of a host with a guest molecule. We show such interactions can be modulated by carefully defining the local molecular environment to give a specific chemical outcome. Particularly, the selectivity of a host toward two different ions (Ca2+ and Al3+) is defined by it being in solution or the physisorbed state. In solution, the host displays greater selectivity toward Ca2+. When physisorbed, the selectivity profile of the host is reversed with enhanced binding of Al3+. This demonstrates a single host molecule can be tailored to selectively bind multiple guests by altering its nanoenvironment.