All posts by Tony Crawshaw

Generating whispering gallery mode spectra

9 March 2017:

A new publication from CNBP researchers (lead author Jonathan Hall pictured) presents a new model for generating whispering gallery mode spectra for multilayer microspheres.

The work has just been reported in the journal ‘Optics Express’ and is accessible online.

Journal: Optics Express.

Title: Unified theory of whispering gallery multilayer microspheres with single dipole or active layer sources.

Authors: Jonathan M. M. Hall, Tess Reynolds, Matthew R. Henderson, Nicolas Riesen, Tanya M. Monro, and Shahraam Afshar.

Abstract: The development of a fast and reliable whispering gallery mode (WGM) simulator capable of generating spectra that are comparable with experiment is an important step forward for designing microresonators. We present a new model for generating WGM spectra for multilayer microspheres, which allows for an arbitrary number of concentric dielectric layers, and any number of embedded dipole sources or uniform distributions of dipole sources to be modeled. The mode excitation methods model embedded nanoparticles, or fluorescent dye coatings, from which normalized power spectra with accurate representation of the mode coupling efficiencies can be derived. In each case, the emitted power is expressed conveniently as a function of wavelength, with minimal computational load. The model makes use of the transfer-matrix approach, incorporating improvements to its stability, resulting in a reliable, general set of formulae for calculating whispering gallery mode spectra. In the specific cases of the dielectric microsphere and the single-layer coated microsphere, our model simplifies to confirmed formulae in the literature.

CNBP AI wins 40under40 awards

8 March 2017:

CNBP Associate Investigator A/Prof Kevin Pfleger, from the Harry Perkins Institute of Medical Research, has won the Intrapreneur category, as well as receiving the coveted City of Perth Strategic Alliance Award at the Business News 40under40 Awards in Perth on Wednesday 8th March.

“I’m passionate about helping my fellow scientists by facilitating a network of mentors that accelerate the transition of discoveries in the laboratory to treatments for the community,” A/Prof Pfleger said.

More information can be found on the Harry Perkins Institute of Medical Research news site.

 

 

 

New PhD student Yuan Liu

2 March 2017:

The Macquarie University node of CNBP welcomes a new PhD student to the team – Yuan Liu.

Yuan will study under the supervision of Center Deputy Director Prof. Ewa Goldys and Centre Research Fellow A/Prof. Guozhen Liu.

Her project will explore the construction of a novel biosensing platform for quantitatively detecting exosomes which can be employed as a potential biomarker for non-invasive disease diagnosis.

Previously, Yuan obtained her Masters Degree of Medicine from Shihezi University, China. During that time she majored in pharmaceutical analysis and her research was focused on the construction, characterization and application of electrochemical and gas sensors under the guidance of Prof. Hui Tang and Prof. Yingchun Li.

Welcome aboard Yuan!

New nanoparticle discovery to aid super-resolution imaging

23 February 2017:

Our researchers and collaborators have made a breakthrough in the development of practical super-resolution optical microscopy that will pave the way for the detailed study of live cells and organisms, on a scale 10 times smaller than can currently be achieved  with conventional microscopy.

Reported in Nature, it was demonstrated that bright luminescent nanoparticles can be switched on and off using a low-power infrared laser beam, and used to achieve images with a super resolution of 28nm (about 1/36 the wavelength of light).

Find out more by accessing the paper online.

Journal: Nature

Title: Amplified stimulated emission in upconversion nanoparticles for super-resolution nanoscopy.

Authors: Yujia Liu, Yiqing Lu, Xusan Yang, Xianlin Zheng, Shihui Wen, Fan Wang, Xavier Vidal, Jiangbo Zhao, Deming Liu, Zhiguang Zhou, Chenshuo Ma, Jiajia Zhou, James A. Piper, Peng Xi & Dayong Jin.

 

Hyperspectral unmixing methodology validated

Aziz Rehman10 February 2017:

A new publication from CNBP researchers Aziz Ul Rehman (pictured), Ayad Anwer, Martin Gosnell, Saabah Mahbub, Guozhen Liu and Ewa Goldys demonstrates the validation of an innovative hyperspectral unmixing methodology, that can derive chemical information from cell colour.

The work has just been reported in the journal ‘Biomedical Optics Express’ and is accessible online.

Journal: Biomedical Optics Express.

Title: Fluorescence quenching of free and bound NADH in HeLa cells determined by hyperspectral imaging and unmixing of cell autofluorescence.

Authors: Aziz Ul Rehman, Ayad G. Anwer, Martin E. Gosnell, Saabah B. Mahbub, Guozhen Liu, and Ewa M. Goldys.

Abstract: Carbonyl cyanide-p-trifluoro methoxyphenylhydrazone (FCCP) is a well-known mitochondrial uncoupling agent. We examined FCCP-induced fluorescence quenching of reduced nicotinamide adenine dinucleotide / nicotinamide adenine dinucleotide phosphate (NAD(P)H) in solution and in cultured HeLa cells in a wide range of FCCP concentrations from 50 to 1000µM. A non-invasive label-free method of hyperspectral imaging of cell autofluorescence combined with unsupervised unmixing was used to separately isolate the emissions of free and bound NAD(P)H from cell autofluorescence. Hyperspectral image analysis of FCCP-treated HeLa cells confirms that this agent selectively quenches fluorescence of free and bound NAD(P)H in a broad range of concentrations. This is confirmed by the measurements of average NAD/NADH and NADP/NADPH content in cells. FCCP quenching of free NAD(P)H in cells and in solution is found to be similar, but quenching of bound NAD(P)H in cells is attenuated compared to solution quenching possibly due to a contribution from the metabolic and/or antioxidant response in cells. Chemical quenching of NAD(P)H fluorescence by FCCP validates the results of unsupervised unmixing of cell autofluorescence.

Gold-loaded liposomes with photosensitizers for PDT

2 February 2017:

A new publication from CNBP researchers Wei Deng (pictured), Sandhya Clement and Ewa Goldys indicates that gold-loaded liposomes incorporating photosensitizers may serve as improved agents in photodynamic therapy and chemotherapy. The work has just been reported in the International Journal of Nanomedicine and is accessible online.

Journal: International Journal of Nanomedicine.

Title: Light-triggered liposomal cargo delivery platform incorporating photosensitizers and gold nanoparticles for enhanced singlet oxygen generation and increased cytotoxicity

Authors: Zofia Kautzka, Sandhya Clement, Ewa M Goldys and Wei Deng.

Abstract: We developed light-triggered liposomes incorporating 3–5 nm hydrophobic gold
nanoparticles and Rose Bengal (RB), a well-known photosensitizer used for photodynamic
therapy. Singlet oxygen generated by these liposomes with 532 nm light illumination was
characterized for varying the molar ratio of lipids and gold nanoparticles while keeping
the amount of RB constant. Gold nanoparticles were found to enhance the singlet oxygen
generation rate, with a maximum enhancement factor of 1.75 obtained for the molar ratio of hydrogenated soy l-α-phosphatidylcholine:1,2-dioleoyl-sn-glycero-3-hosphoethanolamineN-(hexanoylamine): gold of 57:5:17 compared with liposomes loaded with RB alone. The experimental results could be explained by the local electric field enhancement caused by gold nanoparticles. We further assessed cellular cytotoxicity of gold-loaded liposomes by encapsulating an antitumor drug, doxorubicin (Dox); such Dox-loaded liposomes were applied to human colorectal cancer cells (HCT116) and exposed to light. Gold-loaded liposomes containing RB and Dox where Dox release was triggered by light were found to exhibit higher cytotoxicity compared with the liposomes loaded with RB and Dox alone. Our results indicate that goldloaded liposomes incorporating photosensitizers may serve as improved agents in photodynamic therapy and chemotherapy.

New Masters student

31 January 2017:

We welcome new Masters student Weikun Huang (pictured left) to the CNBP team at the University of Adelaide.

Weikun’s project aims to design and construct multiplexing microstructured optical fibre to quantify the concentration of metal ions (K+, Ca2+) and glucose. This paving the way for the monitoring of dynamic changes in extracellular and intracellular K+ and Ca2+ concentrations in real time and potentially establishing a new therapeutic strategy for type 2 diabetes.

CNBP Investigator Prof Heike Ebendorff-Heidepriem noted that Weikun’s project closley supported CNBP research in developing new sensors to answer important biological questions.

Weikun graduated from the College of Veterinary Medicine at Jilin University, China. As an undergraduate in veterinary medicine, he looked into the development of inflammatory response during fatty liver and subacute rumen acidosis, applying a series of biomedical techniques.

Welcome to the team Weikun!

 

Grant success

30 January 2017:

CNBP researchers at Macquarie University – Research Fellow Lindsay Parker (pictured left) and A/Prof Andrei Zvyagin have been successful as Chief Investigators on a $100,000 Macquarie University Research Infrastructure Block Grant.

The grant will support a research assistant (Anna Guller, CNBP PhD candidate) to help build capacity in and use Macquarie University’s bioreactor equipment towards the production and maintenance of live bioartificial tissues for sustainable scientific use.

The CNBP researchers will be collaborating with the University’s Faculty of Medicine to use these artificial biotissues in order to assess nanoparticle detection capabilities/depths in complex tissue structures.

Lead CI on the grant is Professor Qian Yi in the Faculty of Medicine.

New ‘smart needle’ to make brain surgery safer

20 January 2017:

A new high-tech medical device to make brain surgery safer has been developed by researchers at the Centre for Nanoscale BioPhotonics located at the University of Adelaide.

Led by CNBP Investigator Professor Robert McLaughlin (pictured), the tiny imaging probe, encased within a brain biopsy needle, lets surgeons ‘see’ at-risk blood vessels as they insert the needle, allowing them to avoid causing bleeds that can potentially be fatal.

Over the past six months, the “smart needle” has been used in a pilot trial with 12 patients undergoing neurosurgery at Sir Charles Gairdner Hospital in Western Australia.

Today, Education and Training Minister Senator Simon Birmingham, was shown the high tech needle and the laboratory where it was developed at a special event at the University of Adelaide.

“This smart biopsy device is an outstanding example of how our investment in research can translate into real benefits for industries and ultimately for Australians,” Minister Birmingham said.

A press release related to this activity can be viewed online, as can a YouTube video detailing  this innovative translational research.

Below – CNBP Director Professor Mark Hutchinson (left) and CNBP Investigator Professor  Robert McLaughlin (second right) look on as Senator Simon Birmingham (centre) explores the ‘smart needle device’.