Monthly Archives: August 2017

School tour of Braggs labs

31 August 2017:

Caritas College students visiting the University of Adelaide for a ‘science day’ were shown around laboratory spaces in the Braggs Building by CNBP PHD students Kathryn Palasis (pictured) and Georgina Sylvia.

The 23 Year 9 school students were given a tour through a synthetic chemistry lab and then spoke with both CNBP researchers about the work being done and their journeys through University. This was followed by a further tour through a fibre-optics laboratory.

According to Kathryn, “The students seemed engaged and interested, particularly with the fibre-optics tour. And feedback from Amy (who organised the day) was that the students enjoyed it and that the teachers were very appreciative. Personally I spoke to a girl who said she was interested in studying science at university which was very pleasing to hear, and hopefully we encouraged others to see it as an appealing career path as well.”

Exploring small-sized nanoflakes

29 August 2017:

Size-dependent structural and electronic properties of MoSmonolayer nanoflakes, of sizes up to 2nm, have been investigated by CNBP researchers using density-functional theory (DFT). The paper, published in Scientific Reports is accessible online.

Journal: Scientific Reports.

Publication title: A study of size-dependent properties of MoSmonolayer nanoflakes using density-functional theory.

Authors: M. Javaid (pictured), Daniel W. Drumm, Salvy P. Russo & Andrew D. Greentree.

Abstract: Novel physical phenomena emerge in ultra-small sized nanomaterials. We study the limiting small-size-dependent properties of MoS2 monolayer rhombic nanoflakes using density-functional theory on structures of size up to Mo35S70 (1.74 nm). We investigate the structural and electronic properties as functions of the lateral size of the nanoflakes, finding zigzag is the most stable edge configuration, and that increasing size is accompanied by greater stability. We also investigate passivation of the structures to explore realistic settings, finding increased HOMO-LUMO gaps and energetic stability. Understanding the size-dependent properties will inform efforts to engineer electronic structures at the nano-scale.

New technique to aid IVF embryo selection

28 August 2017:

Researchers at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) have successfully developed an advanced new imaging technique, which can help assess the quality of early-stage embryos.

The research, reported in the journal ‘Human Reproduction’ has the potential to significantly benefit the IVF industry of the future, improving assisted reproduction outcomes for women.

“We use a special type of imaging to show differences in the metabolism and chemical make-up of embryos before they’ve been implanted,” says lead author Dr Mel Sutton-McDowall (pictured).

“This technique can give us an objective measure of which embryo to choose as part of the IVF process.”

This ‘hyperspectral imaging’ measures light that cells naturally produce during their normal activities. The light or ‘autoflorescence’ produced changes according to the chemical reactions or metabolism going on in the cell.

Being able to measure embryo metabolism is viewed by many researchers as one of the most important factors as to whether a particular IVF program will be successful.

However, says Dr Sutton-McDowall, fertility specialists take a largely subjective approach in deciding which embryos should be used.

“Pre-implantation screening of embryos generally takes place under a normal optical microscope. Although it’s quite easy to discern poor embryos (due to differences in uniformity), it is far harder for the clinician to determine objectively, the viability of the other embryos,” she says.

“The challenge is how to choose the single healthiest embryo out of this group to maximise the chances of pregnancy.”

Dr Sutton-McDowall sees the use of hyperspectral imaging as a new tool that can be combined with other diagnostic methods to provide a more accurate and objective embryo viability assessment.

“The benefit of hyperspectral imaging is that it can capture information-rich content of inspected objects. It analyses every pixel in an image for its light intensity at differing wavelengths,” she says

“This lets us drill down and analyse the hyperspectral signature of each individual embryo, looking for known or anomalous characteristics. It lets us discriminate between embryos, but also measuring metabolic differences within individual embryos. We predict that embryos that have cells with homogeneous (uniform) metabolic profiles are the healthier ones.”

To date, this imaging technology has only been tested on cattle embryos but Dr Sutton-McDowall notes that the technique is extremely promising.

“It offers benefits of being a non-invasive imaging approach that provides real-time information to the clinician,” she says.

The paper is accessible online.

Journal: Human Reproduction.

Publication title: Hyperspectral microscopy can detect metabolic heterogeneity within bovine post-compaction embryos incubated under two oxygen concentrations (7% versus 20%).

Authors: Melanie L. Sutton-McDowall, Martin Gosnell, Ayad G. Anwer, Melissa White, Malcolm Purdey, Andrew D. Abell, Ewa M. Goldys, Jeremy G. Thompson.

Abstract: 

STUDY QUESTION
Can we separate embryos cultured under either 7% or 20% oxygen atmospheres by measuring their metabolic heterogeneity?

SUMMARY ANSWER
Metabolic heterogeneity and changes in metabolic profiles in morula exposed to two different oxygen concentrations were not detectable using traditional fluorophore and two-channel autofluorescence but were detectable using hyperspectral microscopy.

WHAT IS KNOWN ALREADY
Increased genetic and morphological blastomere heterogeneity is associated with compromised developmental competence of embryos and currently forms the basis for embryo scoring within the clinic. However, there remains uncertainty over the accuracy of current techniques, such as PGS and time-lapse microscopy, to predict subsequent pregnancy establishment.

STUDY DESIGN, SIZE, DURATION
The impact of two oxygen concentrations (7% = optimal and 20% = stressed) during post-fertilisation embryo culture was assessed. Cattle embryos were exposed to the different oxygen concentrations for 8 days (D8; embryo developmental competence) or 5 days (D5; metabolism measurements). Between 3 and 4 experimental replicates were performed, with 40–50 embryos per replicate used for the developmental competency experiment, 10–20 embryos per replicate for the fluorophore and two-channel autofluorescence experiments and a total of 21–22 embryos used for the hyperspectral microscopy study.

PARTICIPANTS/MATERIALS, SETTING, METHODS
In-vitro produced (IVP) cattle embryos were utilised for this study. Post-fertilisation, embryos were exposed to 7% or 20% oxygen. To determine impact of oxygen concentrations on embryo viability, blastocyst development was assessed on D8. On D5, metabolic heterogeneity was assessed in morula (on-time) embryos using fluorophores probes (active mitochondria, hydrogen peroxide and reduced glutathione), two-channel autofluorescence (FAD and NAD(P)H) and 18-channel hyperspectral microscopy.

MAIN RESULTS AND THE ROLE OF CHANCE
Exposure to 20% oxygen following fertilisation significantly reduced total blastocyst, expanded and hatched blastocyst rates by 1.4-, 1.9- and 2.8-fold, respectively, compared to 7% oxygen (P < 0.05), demonstrating that atmospheric oxygen was a viable model for studying mild metabolic stress. The metabolic profiles of D5 embryos was determined and although metabolic heterogeneity was evident within the cleavage stage (i.e. arrested) embryos exposed to fluorophores, there were no detectable difference in fluorescence intensity and pattern localisation in morula exposed to the two different oxygen concentrations (P > 0.05). While there were no significant differences in two-channel autofluorescent profiles of morula exposed to 7% and 20% oxygen (main effect, P > 0.05), morula that subsequently progressed to the blastocyst stage had significantly higher levels of FAD and NAD(P)H fluorescence compared to arrested morula (P < 0.05), with no change in the redox ratio. Hyperspectral autofluorescence imaging (in 18-spectral channels) of the D5 morula revealed highly significant differences in four features of the metabolic profiles of morula exposed to the two different oxygen concentrations (P < 0.001). These four features were weighted and their linear combination revealed clear discrimination between the two treatment groups.

LIMITATIONS, REASONS FOR CAUTION
Metabolic profiles were assessed at a single time point (morula), and as such further investigation is required to determine if differences in hyperspectral signatures can be detected in pre-compaction embryos and oocytes, using both cattle and subsequently human models. Furthermore, embryo transfers should be performed to determine the relationship between metabolic profiles and pregnancy success.

WIDER IMPLICATIONS OF THE FINDINGS
Advanced autofluorescence imaging techniques, such as hyperspectral microscopy, may provide clinics with additional tools to improve the assessment of embryos prior to transfer.

Nano-diamond arrays on glass

23 August 2017:

Researchers from CNBP’s RMIT University node (lead author Ashleigh Heffernan), have published a paper demonstrating a directed self-assembly method to position nanodiamonds on glass. The method, allowing for the statistical quantification of fluorescent nanoparticles provides a step towards fabrication of hybrid photonic devices for applications from quantum cryptography to sensing.

The paper is accessible online.

Journal: Scientific Reports.

Publication title: Nanodiamond arrays on glass for quantification and fluorescence characterisation.

Authors: Ashleigh H. Heffernan, Andrew D. Greentree & Brant C. Gibson.

Abstract: Quantifying the variation in emission properties of fluorescent nanodiamonds is important for developing their wide-ranging applicability. Directed self-assembly techniques show promise for positioning nanodiamonds precisely enabling such quantification. Here we show an approach for depositing nanodiamonds in pre-determined arrays which are used to gather statistical information about fluorescent lifetimes. The arrays were created via a layer of photoresist patterned with grids of apertures using electron beam lithography and then drop-cast with nanodiamonds. Electron microscopy revealed a 90% average deposition yield across 3,376 populated array sites, with an average of 20 nanodiamonds per site. Confocal microscopy, optimised for nitrogen vacancy fluorescence collection, revealed a broad distribution of fluorescent lifetimes in agreement with literature. This method for statistically quantifying fluorescent nanoparticles provides a step towards fabrication of hybrid photonic devices for applications from quantum cryptography to sensing.

Talking science at UoA Open Day

20 August 2017:

CNBP volunteers at the University of Adelaide Open Day took the opportunity to set-up a stand and to demonstrate Centre related science, Sunday 20th August, 2017.

The Open Day, showcasing programs, facilities, and options for student study at the University, saw many thousands of visitors to Campus and the CNBP team was ready!

CNBP experiments and demonstrations were on offer, ranging from the opportunity to play with lasers, through to checking out spinal-cord cells through a microscope.

And for those visitors to the stand who really wanted to know more about the innovative biophotonics science that the CNBP undertakes, there were giveaway goodies including t-shirts, drink bottles, pens and brochures.

Below: CNBP researcher Vicky Staikopoulos encouraging members of the public to ‘Ask about science.’

CNBP at Macquarie Uni Open Day

19 August 2017:

‘The power of light to measure’ was the phrase commonly expressed by Centre researchers staffing the CNBP stand at this year’s Macquarie University Open Day.

This was in response to potential University students and their family members, who were looking to find out more about nanoscale biophotonics as well as to better understand potential opportunities that might be open to graduates who successfully gain a degree in biology, physics or chemistry.

Many of the visitors left the CNBP stand impressed as to the broad application of biophotonics in the healthcare, food safety and manufacturing sectors. They also learnt more about the current activities of the CNBP, particularly in creating new sensing and imaging technologies to better understand molecular activity taking place within the living body.

The Open Day at Macquarie University saw many thousands of people visit Campus and engage with both staff and current students, in their exploration of courses open for undergraduate study.

Below, CNBP researchers Dr Wei Deng (left) and Dr Lianmei Jiang (right) get ready to talk nanoscale biophotonics as the doors open at the 2017 MQ Uni Open Day.

 

Outreach at Concordia College

16 August 2017:

Students from Concordia College got the low-down on STEM careers—as well as learnt more about lasers, laboratories and the life of a scientist at a school outreach event organised and run by CNBP researchers from the University of Adelaide.

The event, celebrating National Science Week, saw a team of CNBP scientists and researchers visit Concordia College and present a variety of talks, DIY laboratory videos and science demonstrations, to over 150 Year 9 students with an interest in science, technology, engineering and maths (STEM).

CNBP’s Dr Hannah Brown, present on the day, sees outreach as a key responsibility for the science community.

“Getting high school students interested and engaged in STEM subjects is critical—not only to inspire future generations of young scientists but also in supporting the Australian economy more generally. What we hope to do with our outreach efforts is to show that science and technology can be fun and exciting, and potentially rewarding as a future career choice as well.”

Following the event, feedback from both students and teachers present was hugely positive with the CNBP team also gaining a great deal of satisfaction from their interactions and demonstration efforts.

Below: CNBP researchers Hannah Brown, Georgios Tsiminis, Patrick Capon and Aimee Horsfall with students, at the conclusion of a successful session of science outreach at Concordia College.

New CNBP research assistant

16 August 2017:

CNBP would like to welcome Robyn Kievit to the team. Located at the University of Adelaide, Robyn has joined the CNBP as a research assistant. She will primarily work within the Origins of Sensing biological challenges group (understanding the role of brain immune signals in the creation of chronic pain) with Dr Sanam Mustafa. Robyn will also set-up standard sensor validation protocols for testing of novel sensors being developed by Prof Andrew Abell’s team.

It’s great to have you on board Robyn!

Launch of CNBP and CU partnership

15 August 2017:

The University of Colorado Boulder (CU) and the Centre for Nanoscale BioPhotonics (CNBP) have officially announced their research partnership status at a launch event that took place at CU today.

The collaboration between the CNBP, an Australian Research Council Centre of Excellence, and the University of Colorado Boulder, will explore the use of novel CNBP biophotonics tools and techniques to examine in real-time, neuroinflammatory processes that govern behavior.

The novel immune sensing technologies developed at CNBP will allow circuit-specific measurement of immune molecule release during stress-related paradigms in rodents performed at the University of Colorado Boulder.

The overarching goal of the collaboration is to better inform intervention efforts
focused on stress- and ageing-related diseases.

Partner Investigators at CU are Professor Steven Maier and Professor Linda Watkins with CU’s Dr Michael Baratta (the successful recipient of the CNBP-American Australian Association Fellowship in 2016), also working closely with this partnership.

Below: CNBP Director Prof Mark Hutchinson (left) presents a partner plaque to Partner Investigators – Professor Steven Maier and Professor Linda Watkins.

 

Low-power nonlinear photonic effects

15 August 2017:

Dr Ivan Maksymov from CNBP’s RMIT University node, visited the Department of Physics and Astronomy at Macquarie University Aug 15, 2017 and gave a well attended seminar.

The talk centred on the theory  of low-power nonlinear photonic effects and was formally titled, “Nonlinear optics with low-power light: Transduction of acoustic nonlinearities into the optical domain.”