Monthly Archives: September 2017

New med-tech zinc sensor developed

29 September 2017:

A new zinc sensor has been developed by CNBP researchers, which will allow for a deeper understanding of the dynamic roles that metal ions play in regulating health and disease in the living body.

The research, published in the journal ACS Omega reports that the newly designed chemical sensor can detect and measure zinc levels in cells. It also has the functionality and portability to take continuous or repeated measurements within a single biological sample.

“This makes the sensor potentially suitable for use in future diagnostic tools that could open up entirely new windows into the body,” says lead author of the research Dr Sabrina Heng (pictured), Research Fellow at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), at the University of Adelaide.

Read more at PHYS.ORG.

Automated image analysis aids bladder cancer diagnosis

28 September 2017:

An automated image analysis technique has been developed by CNBP researchers (lead researcher Dr Martin Gosnell pictured) that is able to aid in the diagnosis of bladder cancer, and could potentially reduce the number of biopsies being taken unnecessarily.

Read the full article detailing the research and future opportunities, featured in Optics.org.

New med-tech zinc sensor developed

27 September 2017:

A new zinc sensor has been developed and reported by CNBP researchers, which will allow for a deeper understanding of the dynamic roles that metal ions play in regulating health and disease in the living body.

The research, published in the journal ‘ACS Omega’ reports that the newly designed chemical sensor can detect and measure zinc levels in cells. It also has the functionality and portability to take continuous or repeated measurements within a single biological sample.

“This makes the sensor potentially suitable for use in future diagnostic tools that could open up entirely new windows into the body,” says lead author of the research Dr Sabrina Heng (pictured), Research Fellow at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), at the University of Adelaide.

Read the full CNBP media release here and the publication here.

Journal: ACS Omega.

Publication title: A Rationally Designed Probe for Reversible Sensing of Zinc and Application in Endothelial Cells.

Authors: Sabrina Heng, Philipp Reineck, Achini K. Vidanapathirana, Benjamin J. Pullen, Daniel W. Drumm, Lesley J. Ritter, Nisha Schwarz, Claudine S. Bonder, Peter J. Psaltis, Jeremy G. Thompson, Brant C. Gibson , Stephen J. Nicholls, and Andrew D. Abell.

Abstract: Biologically compatible fluorescent ion sensors, particularly those that are reversible, represent a key tool for answering a range of fundamental biological questions. We report a rationally designed probe with a 6′-fluoro spiropyran scaffold (5) for the reversible sensing of zinc (Zn2+) in cells. The 6′-fluoro substituent overcomes several limitations normally associated with spiropyran-based sensors to provide an improved signal-to-background ratio and faster photoswitching times in aqueous solution. In vitro studies were performed with 5 and the 6′-nitro analogues (6) in HEK 293 and endothelial cells. The new spiropyran (5) can detect exogenous Zn2+ inside both cell types and without affecting the proliferation of endothelial cells. Studies were also performed on dying HEK 293 cells, with results demonstrating the ability of the key compound to detect endogenous Zn2+ efflux from cells undergoing apoptosis. Biocompatibility and photoswitching of 5 were demonstrated within endothelial cells but not with 6, suggesting the future applicability of sensor 5 to study intracellular Zn2+ efflux in these systems.

New technique to aid bladder cancer diagnosis

25 September 2017:

A new and innovative automated computer technique has been developed by CNBP researchers that is able to significantly aid in the diagnosis of bladder cancer.

The technique—which allows suspect lesion images to be quickly and effectively analysed and then classified for cancer risk, has been reported in the medical journal ‘Urologic Oncology’.

“What we’ve done is develop a computer program to carry out an automated analysis of cystoscopy images,” says lead author of the research, Dr Martin Gosnell, Researcher at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) at Macquarie University and Director at Quantitative Pty Ltd.

Cystoscopy is one of the most reliable methods for diagnosing bladder cancer explains Dr Gosnell.

“Images are taken of the bladder and its insides for suspicious lesions during a routine clinical patient evaluation. Dependent on the findings, this initial scan can then be followed up by a referral to a more experienced urologist, and a biopsy of the suspicious tissue can be undertaken.”

The issue says Dr Gosnell is that the clinician examining the initial images makes a visual judgement based on their professional expertise as to the next steps of action that should be undertaken—such as the need to take a biopsy for subsequent pathological analysis.

“Potential errors and unnecessary further interventions may result from the subjective character of this initial visual assessment.”

“What we’ve done,” says Dr Gosnell, “is to create an automated image analysis technique which can identify tissue and lesions as either high-risk or minimal-risk.”

Read the full CNBP media release and the science paper here.

Journal: Urologic Oncology.

Publication title: Computer-assisted cystoscopy diagnosis of bladder cancer.

Authors: Martin E. Gosnell (pictured top), Dmitry M. Polikarpov, Ewa M. Goldys, Andrei V. Zvyagin and David A. Gillatt.

Abstract:

Objectives

One of the most reliable methods for diagnosing bladder cancer is cystoscopy. Depending on the findings, this may be followed by a referral to a more experienced urologist or a biopsy and histological analysis of suspicious lesion. In this work, we explore whether computer-assisted triage of cystoscopy findings can identify low-risk lesions and reduce the number of referrals or biopsies, associated complications, and costs, although reducing subjectivity of the procedure and indicating when the risk of a lesion being malignant is minimal.

Materials and methods

Cystoscopy images taken during routine clinical patient evaluation and supported by biopsy were interpreted by an expert clinician. They were further subjected to an automated image analysis developed to best capture cancer characteristics. The images were transformed and divided into segments, using a specialised color segmentation system. After the selection of a set of highly informative features, the segments were separated into 4 classes: healthy, veins, inflammation, and cancerous. The images were then classified as healthy and diseased, using a linear discriminant, the naïve Bayes, and the quadratic linear classifiers. Performance of the classifiers was measured by using receiver operation characteristic curves.

Results

The classification system developed here, with the quadratic classifier, yielded 50% false-positive rate and zero false-negative rate, which means, that no malignant lesions would be missed by this classifier.

Conclusions

Based on criteria used for assessment of cystoscopy images by medical specialists and features that human visual system is less sensitive to, we developed a computer program that carries out automated analysis of cystoscopy images. Our program could be used as a triage to identify patients who do not require referral or further testing.

Below: Dr Martin Gosnell and Prof Ewa Goldys.

CNBP at AstroLight Festival

23 September 2017:

CNBP scientists joined forces with astronauts, astronomers, scientists, stargazers and artists to present a night starring astronomy and light at the annual AstroLight Festival, held at Scienceworks in Melbourne, Saturday 23 September, 2017.

The public event, which attracted more than 1,500 attendees, saw eleven CNBP team members involved – giving talks, undertaking light-focused science demonstrations and hosting an interactive stall.

Specific talks included:

  • Science Fiction Science Fact – Laser Combat in Movies  from A/Prof Brant Gibson, CNBP node leader at RMIT
  • The Spark of Life – Dr Hannah Brown, CNBP Fellow from the University of Adelaide
  • Fluorescent Proteins – From Nature to the Lab from CNBP PhD student  Emma Wilson

Event feedback from A/Prof Gibson was extremely positive. “There was plenty of interest in our light-based CNBP science and some great questions from the public both young and old. The team really pulled together to make our participation such a success – both on the night and in the lead up activity, and with the development of the displays and demonstrations.”

Below – The CNBP team ready to do outreach!

Glycan identification and quantitation

21 September 2017:

Christopher Ashwood, CNBP PhD candidate, visited Ireland in September 2017, performing an oral presentation at the 16th Human Proteome Organisation World Congress with a presentation titled: “Open-glycomics: An open-access platform for software-assisted glycan identification and quantitation”.

He also visited the National Institute for Bioprocessing Research and Training (NIBRT) where he also presented his research.

Talk summary: Analysing glycomics data, the study of carbohydrates, is largely manual resulting in low throughput and can be subject to human error. Using a software package named Skyline, Chris has automated the most tedious parts of this data analysis and generated the data in a standard format for use by other glycomics researchers and bioinformaticians. Future research will standardise and automate this analysis further for application towards the currently booming biopharmaceutical industry.

Children’s University Regional Lecture Series

17 September 2017:

Georgina Sylvia, CNBP researcher, was recently involved in two outreach events organised as part of the Children’s University Regional Lecture Series, which aims to stimulate interest in Science, Technology, Engineering and Mathematics (STEM subjects) for school children in Years 6-9.

At the first event at Renmark, she presented exciting chemistry demonstrations to year 7 and 8 students from the local community at the McCormick Centre for the Environment. The students were engaged in groups of 25 and encouraged to participate in the experiments and to ask and discuss science related queries.

The best quote of the day heard by Georgina – “Chemistry is awesome!”

The second outreach event was held at ‘Riverland Field Days’, 15-16th September, 2017. This community event is held annually “showcasing horticultural, agricultural and general farming products and services along with many general exhibitors.”

Children’s University, as a part of the Regional Lecture Series, set up a stall where Georgina and other researchers demonstrated and engaged kids in activities such as Engineering (building catapults from popsicle sticks), Chemistry (Slime making) and Biology (an aroma-sensory panel activity).

Feedback from Georgina – “The best part of this event was encouraging parents and caregivers to get involved in the activities with their kids, and to learn things together. Another great experience for me was encouraging a little girl to get involved in the catapult-making engineering activity, and seeing her so excited to participate!”

Below – Georgina (second right) at the Field Days event.

Concordia students visit CNBP labs

14 September 2017:

Eighty Concordia College students with an interest in STEM undertook a series of educational tours at CNBP laboratories at the University of Adelaide—forty students visiting Wednesday 6th September and a further forty students visiting Wednesday 13th September, 2017.

The students were hosted by a number of CNBP researchers, undertaking laboratory tours in both the Braggs and Health and Medical Sciences buildings.

As well as getting an introduction to CNBP and biophotonic related science, the students were shown a range of CNBP activity and work-spaces. This included demonstrations of advanced needle probes and optical imaging systems, hands-on demonstrations of near-infrared light scanners, use of a 3D metal printer and tours of the Centre’s glass and optical fibre fabrication facilities, as well as tours of the  embryology laboratory where embryo culture and cryopreservation techniques were also able to be shown.

Emily Johnson, Middle Years Programme Coordinator from Concordia College noted, “All of the students (and teachers) really enjoyed the sessions. They came back quite buzzing and extremely interested in what they saw.”

Feedback from the CNBP researchers was also extremely positive with many noting the excellent questions posed by the students during the lab tour demonstrations and activity.

CNBP science at the Calyx

12 September 2017:

CNBP researchers Dr Denitza Denkova and Dr Martin Ploschner took their luminescence and fluorescence science expertise to the general public, at a special after-hours event known as ‘Science at the Calyx’ at the Royal Botanic Garden in Sydney.

Presenting to an audience of approximately sixty people, the CNBP scientists focused on giving members of the public information about the origins of luminescence and examples of it being used – from everyday life to medical applications, and the amazing natural phenomenon of bioluminescence which can be found in plants, animals and fungi.

Following the hour long talk, there were demonstrations including the use of fluorescent bubbles, a ‘magical’ fluorescent screen, the showing of several fluorescent specimens and an examination of fluorescence in money and documents for security purposes. There was also as ample time for attendees to talk to the researchers about their work with fluorescent molecules and nanoparticles.

According to Dr Denkova, the event was highly rewarding.

“There was plenty of opportunity for personal interaction which was embraced by attendees. Many had an interest in the medical applications related to fluorescence, but there were also great questions on practical everyday activities – such as how to paint bikes with fluorescent paint to help improve road safety. Following the talk, people had the chance to walk around the beautiful garden with a UV torch in their hand to discover for themselves which plants are fluorescent. Both Martin and myself enjoyed communicating our science to a wider public!”

First reversible ‘turn-off’ sensor for Glutathione

6 September 2017:

The first reversible ‘turn-off’ sensor for Glutathione has been reported by CNBP researchers in a paper published in the science journal Biosensors.

The paper is accessible online (open access).

Dr Sabrina Heng notes:

γ-Glutamyl-cysteinyl-glycine (GSH) plays a critical role in maintaining redox homeostasis in biological systems and a decrease in its cellular levels is associated with disease. Many diseases including Parkinson’s, cancer, heart diseases and Alzheimer’s are indicated by a decrease in GSH levels. In this case, a ‘turn on’ sensor would result in reduced fluorescence relative to healthy cells. An important advance would come from the development of a sensor that is measurably turned off by GSH and back on by a lower level of GSH. This would then provide an opportunity to sense reduced GSH levels during the onset of important diseases.

With that in mind we have rationally designed, to the best of our knowledge, the first reversible, reaction-based ‘turn-off’ probe that is suitable for sensing decreasing levels of GSH, a situation known to occur at the onset of various diseases.  We have demonstrated that the sensor can be used to detect changes of intracellular GSH in live HEK 293 cells to provide a potentially regenerable sensor for monitoring lower levels of intracellular GSH as associated with the onset of important diseases.

Journal: Biosensors.

Publication title: A Rationally Designed Reversible ‘Turn-Off’ Sensor for Glutathione.

Authors: Sabrina Heng (pictured), Xiaozhou Zhang, Jinxin Pei and Andrew D. Abell.

Abstract: γ-Glutamyl-cysteinyl-glycine (GSH) plays a critical role in maintaining redox homeostasis in biological systems and a decrease in its cellular levels is associated with diseases. Existing fluorescence-based chemosensors for GSH acts as irreversible reaction-based probes that exhibit a maximum fluorescence (‘turn-on’) once the reaction is complete, regardless of the actual concentration of GSH. A reversible, reaction-based ‘turn-off’ probe (1) is reported here to sense the decreasing levels of GSH, a situation known to occur at the onset of various diseases. The more fluorescent merocyanine (MC) isomer of 1 exists in aqueous solution and this reacts with GSH to induce formation of the ring-closed spiropyran (SP) isomer, with a measurable decrease in absorbance and fluorescence (‘turn-off’). Sensor 1 has good aqueous solubility and shows an excellent selectivity for GSH over other biologically relevant metal ions and aminothiol analytes. The sensor permeates HEK 293 cells and an increase in fluorescence is observed on adding buthionine sulfoximine, an inhibitor of GSH synthesis.