All posts by Tony Crawshaw

Sensors for calcium ion

15 June 2017:

Researchers from CNBP (lead author Dr Sabrina Heng pictured), have just had a paper published, reporting on three new spiropyran-based reversible sensors for calcium ion.

Journal: Sensors and Actuators B: Chemical.

Publication title: Photoswitchable calcium sensor: ‘On’–‘Off’ sensing in cells or with microstructured optical fibers.

Authors: Sabrina Heng, Adrian M. Mak, Roman Kostecki, Xiaozhou Zhang, Jinxin Peia, Daniel B. Stubing, Heike Ebendorff-Heidepriema, Andrew D. Abell.

Abstract: Calcium is a ubiquitous intracellular signaling ion that plays a critical role in the modulation of fundamental cellular processes. A detailed study of these processes requires selective and reversible sensing of Ca2+ and an ability to quantify and monitor concentration changes in a biological setting. Three new, rationally designed, synthesized and photoswitchable spiropyran-based reversible sensors for Ca2+ are reported. Sensor 1a is highly selective for Ca2+ with an improved profile relative to the other two analogues, 1b and 1c. Formation of the merocyanine–Ca2+ complex is proportional to an increase in Ca2+ released from HEK293 cells on stimulation with ionomycin. The photophysical processes surrounding the binding of Ca2+ to compound 1a were further explored using computational methods based on density functional theory (DFT). The ability of sensor 1a to bind Ca2+ and photoswitch reversibly was also characterized using silica suspended-core microstructured optical fiber (SCF). These SCF experiments (with 100 nM Ca2+) represent a first step toward developing photoswitchable, minimally invasive and highly sensitive Ca2+ sensing platforms for use in a biological setting.

The paper is accessible online.

School science conference impresses

15 June 2017:

Dr Nima Sayyadi, CNBP researcher, has undertaken guest judging duties at the 2017 Sydney Girls High School Science Conference.

Each year students at Sydney Girls High School complete a research project as part of the NSW Science Curriculum. This project provides Year 9 students with an opportunity to design and perform an investigation into an area of their choice. The annual Science Conference then gives the students a forum where they can present their research to an expert panel.

The panel not only provides students with feedback relating to their investigation, but also determines the projects worthy of further recognition. The determination considers both experimental design and the ability of the student to communicate their ideas.

According to Nima, the standard of work on display was of an incredibly high standard.

“The way that the young students designed their research projects – the hypotheses and preparation and understanding of data limitations was generally quite remarkable.”

Projects being showcased included DNA extraction from fruits with limited facilities through to the analysis of the plastic waste found in water on different beaches in Sydney.

“It was a great experience for me to meet the students, teachers, and other judges from different universities at this event,” concluded Nima.

“Hopefully the passion that these students show for science continues through High School and into tertiary education and beyond.”

Women’s research excellence award

13 June 2017:

Congratulations to Dr Jiawen Li, CNBP researcher at the University of Adelaide, who recently won a Women’s Research Excellence award.

Jiawen’s work is focused on the development of highly novel dual-modality ultrasound/optical coherence tomography imaging probes for diagnosis of disease and for use in surgical applications.

She will be using the award to assist with travel to RMIT and Hong Kong Polytechnic University, where she hopes to build on existing collaborations.

CNBP participates in LEA outreach event

7 June 2017:

With a focus on STEM learning and the need for innovative outreach approaches, Learning Environments Australia (SA chapter) have coordinated a forum at the University of Adelaide, 7 June 2017, which saw significant support from the CNBP.

Prof Mark Hutchinson (CNBP Director), Tony Crawshaw (CNBP Communications and Outreach Coordinator) and Dr Sabrina Heng (CNBP Researcher, pictured) all participated in the LEA forum, providing talks and answering questions as to the Centre’s successful approach to engaging with schools and students and inspiring the next generation of young scientist.

Joanne Rogers, Head of Science, Concordia College who has been closely involved with CNBP outreach activity, talked about the real life changes experienced by her students, resulting from engagement with CNBP scientists. Students she said, had picked up additional science subjects on the back of CNBP school and laboratory visits.

Other University of Adelaide presenters at the event included Kiri Hagenus, Director, Children’s University; Dr Claudia Szabo, Associate Dean, Faculty of ECMS – MOOC in digital literacy for teachers; and Science’s Prof Bob Hill, who discussed successful Faculty outreach initiatives.

Director at SASMA Conference

28 May 2017:

CNBP Director Prof. Mark Hutchinson has given the ‘Henry Kneebone Keynote Presentation’ at this year’s South Australian Sports Medicine Association conference.

The event took place at the Adelaide Oval, Sunday 28 May 2017 with Prof. Hutchinson’s talk titled, “The toll of knowing you are sick: Implications for pain and how we treat it.”

Further conference information can be found online.

 

 

Ambassador visits CNBP laboratories

24 May 2017:

Prof Mark Hutchinson has hosted a visit to the University of Adelaide and CNBP Headquarters of His Excellency Mr Pedro Zwahlen, Ambassador of Switzerland to Australia.

The visit from the Ambassador was a part of a four day trip to Adelaide which included visits to the Tonsley Innovation Precinct, the South Australian Health and Medical Research Institute, various South Australian Government Departments, as well as meetings with the Honourable Jack Snelling MP and the Honourable Zoe Bettison MP.

As a part of the Ambassador’s visit to the University of Adelaide, Prof Hutchinson discussed CNBP science activity, the power of light to measure in the body, and provided a walk-through tour of the Centre’s laboratories.

Below – Prof Mark Hutchinson left, with His Excellency Mr Pedro Zwahlen.

China visit by Centre researcher

16 May 2017:

On a recent trip to China, CNBP Research Fellow A/Prof Guozhen Liu undertook a number of visits and talks, discussing her advanced sensing, nano-particle and bio-imaging work. This included:

5 May-8 May: Attendance at the International Congress on Analytical Sciences 2017 (ICAS2017) at Kaikou, China. Here Guozhen gave an oral presentation with the title “Engineering reduced graphen oxides towards a label-free electrochemical immunosensor for detection of tumor necrosis factor-alpha.”

11 May: Guozhen gave an invited talk titled, “Nanotools for cytokine monitoring in neuroscience” at Prof Zhihong Zhang’s research team at Huazhong University of Science and Technology, Wuhan. Prof Zhang is one of CNBP’s Partner Investigators at HUST.

13-14 May: Guozhen provided a keynote speech, titled, “An optical fibre based ex-vivo device for detection of cytokines” at the 2nd International Congress on Biomedical Imaging and Signal Processing (ICBISP 2017) at Wuhan.

Below: A/Prof Guozhen Liu (right) visiting CNBP Partner Investigator Prof Zhihong Zhang.

 

Maximizing particle concentration

28 April 2017:

A new paper from CNBP researchers reports on an improvement to deterministic lateral displacement arrays, which allows for higher particle concentration enhancement. The work has just been published in the journal ‘Biomicrofluidics’ and is accessible online.

Journal: Biomicrofluidics.

Title: Maximizing particle concentration in deterministic lateral displacement arrays.

Authors: Shilun Feng, Alison M. Skelley, Ayad G. Anwer (pictured top left), Guozhen Liu and David W. Inglis.

Abstract: We present an improvement to deterministic lateral displacement arrays, which allows higher particle concentration enhancement. We correct and extend previous equations to a mirror-symmetric boundary. This approach allows particles to be concentrated into a central channel, no wider than the surrounding gaps, thereby maximizing the particle enrichment. The resulting flow patterns were, for the first time, experimentally measured. The performance of the device with hard micro-spheres and cells was investigated. The observed flow patterns show important differences from our model and from an ideal pattern. The 18 μm gap device showed 11-fold enrichment of 7 μm particles and nearly perfect enrichment—of more than 50-fold—for 10 μm particles and Jurkat cells. This work shows a clear path to achieve higher-than-ever particle concentration enhancement in a deterministic microfluidic separation system.

 

New nanoparticle discovery to aid super-resolution imaging

Prof Jim Piper26 April 2017:

Researchers at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Macquarie University, the University of Technology Sydney (UTS), Peking University and Shanghai Jiao-tong University 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, the international team of researchers has 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.

Professor Jim Piper (pictured), leader of the research team at Macquarie University and the CNBP sees these nanoparticles as having new unique properties. “These allow researchers to see well beyond normal limits of standard microscopes. It will let you see deeper and more clearly at the cellular and intra- cellular level—where proteins, antibodies and enzymes ultimately run the machinery of life.”

The research featured in BioPhotonics World.

Light-triggerable liposomes

21 April 2017:

A new paper from CNBP researchers (lead author Wenjie Chen pictured) reports on the design of a new light-triggerable liposome. The work has just been published in the journal ‘Molecular Therapy: Nucleic Acid’ and is accessible online.

Journal: Molecular Therapy: Nucleic Acid.

Title: Light-triggerable liposomes for enhanced endo/lysosomal escape and gene silencing in PC12 cells.

Authors: Wenjie Chen, Wei Deng, Ewa M. Goldys.

Abstract: Liposomes are an effective gene/drug delivery system, widely used in biomedical applications including gene therapy and chemotherapy. Here we designed a photo-responsive liposome (lipVP) loaded with a photosensitizer verteporfin (VP). This photosensitizer is clinically approved for photodynamic therapy (PDT). LipVP was employed as a DNA carrier for pituitary adenylyl cyclase-activating polypeptide (PACAP) receptor 1 (PAC1R) gene knockdown in PC12 cells. This has been done by incorporating PAC1R antisense oligonucleotides inside the lipVP cavity. Cells which have taken up the lipVP were exposed to light from a UV light source. As a result of this exposure, reactive oxygen species (ROS) were generated from VP, destabilising the endo/lysosomal membranes and enhancing the liposomal release of antisense DNA into the cytoplasm. Endo/lysosomal escape of DNA was documented at different time points based on quantitative analysis of colocalization between fluorescently labelled DNA and endo/lysosomes. The released antisense oligonucleotides were found to silence PAC1R mRNA. The efficiency of this photo-induced gene silencing was demonstrated by a 74 ± 5% decrease in PAC1R fluorescence intensity. Following the light-induced DNA transfer into cells, cell differentiation with exposure to two kinds of PACAP peptides was observed to determine the cell phenotypic change after PAC1R gene knockdown.