Category Archives: MQ

CNBP talks to the pollies at SmP

24 March 2017:

A chance to talk science with Australian politicians and policy influencers was an opportunity seized by CNBP with Centre Investigator Prof Heike Ebendorff-Heidepriem and Centre Research Fellow Dr Andrew Care both in attendance at the annual ‘Science meets Parliament’ (SmP) event, Canberra, 21-22 March, 2017.

Established by Science and Technology Australia, SmP provides 200 scientists with a unique professional development opportunity to get a clear sense of the competing rationalities of science, politics and public policy. The two-day gathering also includes a day at Parliament House, where delegates get the chance to meet privately with parliamentarians.

As part of this activity, Prof Ebendorff-Heidepriem met with Senator Chris Back and Senator Chris Ketter, and also spoke with Shadow Minister of Defence, Richard Marles. In addition, she spoke with many researchers and entrepreneurs from both the University and industry sectors.

“Improving collaboration between the research community and industry was a hot topic in many of the discussions that I had”, said Heike. “Particularly in my meeting with Senator Chris Back. People were also extremely excited about our approach, in using fibres and light to create exciting new windows into the body.”

CNBP’s Dr Andrew Care met with Opposition Leader Bill Shorten’s advisor, discussing gender equality and early education for STEM and also touching on ECR opportunities and improving research and industry ties. He also met MP Adam Bandt, the Greens spokesperson for science.

“Overall it was an extremely rewarding experience,” says Andrew. “Attending SmP gave me the opportunity to explore the political process and to network with many other researchers from academia, industry, and governance. It was fantastic to see science and innovation so high on the government’s agenda.”

A full round up from both days of SmP can be found on the STA web site – Day 1 and Day 2.

Below – MP Adam Bandt and CNBP’s Dr Andrew Care.

 

Gold nanoparticles for bioimaging

22 March 2017:

A new publication from CNBP researchers (lead author Sandhya Clement pictured) reports on a more effective and less harmful gold-based nano-agent for bioimaging and photodynamic therapy treatment for deep tissue tumors.

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

Journal: Microchimica Acta.

Title: Verteprofin conjugated to gold nanoparticles for fluorescent cellular bioimaging and X-ray mediated photodynamic therapy.

Authors: Sandhya Clement, Wenjie Chen, Ayad G. Anwer & Ewa M. Goldys.

Abstract: Photodynamic therapy (PDT) uses photosensitizers, light and molecular oxygen to generate cytotoxic reactive oxygen species. Its effectiveness is limited to <1 cm due to the limited penetration depth of light. The present study compares the PDT effectivity of the photosensitizer verteporfin (VP) conjugated to gold nanoparticles (AuNPs) (a) by using deeply penetrating X-rays administered in standard radiotherapy doses, and (b) by using red light (690 nm). VP was conjugated to AuNPs of around 12 nm size to enhance the interaction of ionizing radiation with PS. For comparison, VP also was directly exposed to X-rays. It is found that VP alone is stimulated by X-rays to generate singlet oxygen. The conjugate to AuNPs also generated a significant amount of singlet oxygen on irradiation with X-rays in comparison to illumination with 690-nm light. It is also found that the rate of singlet oxygen generation is amplified in case of AuNP-conjugated VP compared to VP alone. The performance of the AuNP-VP conjugate and of the VP alone was tested in Panc 1 cells. Their viability was impaired much more in these two scenarios than with the X-ray radiation only. This suggests excellent perspectives for PDT based on VP and with X-ray stimulation, both as a stand-alone photosensitizer and in Au-NP conjugates. Moreover, both VP and AuNP-VP conjugates show bright fluorescence in physiological media for excitation/emission wavelengths in the range of 405/690 nm; hence they can also be used for simultaneous bioimaging.

Breaking apart sugars

9 March 2017:

CNBP scientists Chris Ashwood and Prof Nicki Packer at Macquarie University have shown alternative ways to break apart sugars, improving their characterisation in their latest publication in the area of mass spectrometry (Enhancing structural characterisation of glucuronidated O-linked glycans using negative mode ion trap higher energy collision-induced dissociation mass spectrometry).

The work was published online in the journal Rapid Communications in Mass Spectrometry on 9th March 2017 and was funded by the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics.

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!

Investigating cell metabolism

Aziz Rehman1 March 2017:

A new publication from CNBP researchers (lead author Aziz Ul Rehman pictured) reports on the application of hyperspectral imaging in combination with fluorescence spectroscopy and chemical quenching to provide a new methodology to investigate cell metabolism.

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.

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.

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.

Deep-penetrating photodynamic therapy

4 January 2017:

CNBP researchers (Liuen Liang pictured), report on the deployment of upconversion nanoparticles to enhance the treatment depth of the fluorescent protein KillerRed in photodynamic therapy.

The work was published in the journal ‘Acta Biomaterialia’ and is accessible online.

Journal: Acta Biomaterialia.

Title: Deep-penetrating photodynamic therapy with KillerRed mediated by upconversion nanoparticles.

Authors: Liuen Liang, Yiqing Lu, Run Zhang, Andrew Care, Tiago A. Orteg, Sergey M. Deyev, Yi Qian, Andrei V. Zvyagina.

Abstract: The fluorescent protein KillerRed, a new type of biological photosensitizer, is considered as a promising substitute for current synthetic photosensitizes used in photodynamic therapy (PDT). However, broad application of this photosensitiser in treating deep-seated lesions is challenging due to the limited tissue penetration of the excitation light with the wavelength falling in the visible spectral range. To overcome this challenge, we employ upconversion nanoparticles (UCNPs) that are able to convert deep-penetrating near infrared (NIR) light to green light to excite KillerRed locally, followed by the generation of reactive oxygen species (ROS) to kill tumour cells under centimetre-thick tissue. The photosensitizing bio-nanohybrids, KillerRed-UCNPs, are fabricated through covalent conjugation of KillerRed and UCNPs. The resulting KillerRed-UCNPs exhibit excellent colloidal stability in biological buffers and low cytotoxicity in the dark. Cross-comparison between the conventional KillerRed and UCNP-mediated KillerRed PDT demonstrated superiority of KillerRed-UCNPs photosensitizing by NIR irradiation, manifested by the fact that ∼70% PDT efficacy was achieved at 1-cm tissue depth, whereas that of the conventional KillerRed dropped to ∼7%.