Monthly Archives: April 2019

Collaborative research visit to Peking University

April 2019

CNBP PhD Student Ms Yuan Qi Yeoh enjoyed a two week collaborative visit with Prof Xuefeng Guo’s team at Peking University. Working with Peking University PhD student Xinjiani Chen on a  research project involving the molecular dynamics of the secondary structure of a cyclic photoswitchable peptide.

Yuan Qi had the opportunity to participate in the fabrication process of the single-molecule devices. Specifically, they carried out temperature-dependent experiments using their advanced facilities to probe the molecular dynamics of the secondary structure upon photoswitching.

Yuan Qi says that “It was a great opportunity to collaborate with colleagues at Peking University in such high impact research and enjoyed working in their sophisticated research labs”

Towards a deployable device for cytokine sensing

29 April 2019:

A new research publication (lead author CNBP PhD student Fuyuan Zhang) reports on real-time sensing and detection of cytokines using a 3D optical fibre.

Journal: Molecular Systems Design & Engineering.

Publication title: IFN-γ-induced signal-on fluorescence aptasensors: from hybridization chain reaction amplification to 3D optical fiber sensing interface towards a deployable device for cytokine sensing.

Authors: Fuyuan Zhang, Fei Deng, Guo-Jun Liu, Ryan Middleton, David W. Inglis, Ayad Anwer, Shuo Wang and  Guozhen Liu.

Abstract: Interferon-gamma (IFN-γ), a proinflammatory cytokine, has been used as an early indicator of multiple infectious diseases or tumors. In order to explore the detection capability of a commonly used anti-IFN-γ aptamer, a simple target induced strand-displacement aptasensing strategy was tested by introducing three different complementary strands and two different signal/quencher pairs. The Texas red/BHQ2-based sensor showed the best affinity constant (Kd) of 21.87 ng mL−1. It was found that the strand-displacement aptasensing strategy was impacted by the complementary position and length of the complementary strands. Additionally, the hybridization chain reaction (HCR) amplification strategy was introduced, yielding a 12-fold improved sensitivity of 0.45 ng mL−1. In order to further explore the sensing platform for spatially localized cytokine detection, the Texas red/BHQ2-based strand-displacement aptasensor was successfully fabricated on the 3D optical fiber surface to achieve a deployable sensing device for monitoring IFN-γ based on the fluorescence spots counting strategy. Finally, the three developed aptasensing strategies (strand-displacement strategy, HCR amplification strategy, 3D optical fiber aptasensor) were applied for detection of IFN-γ secreted by PBMCs with comparable results to those of ELISA. The deployable 3D optical fiber aptasensor with the superior sensitivity is potential to be used for detection of spatially localized IFN-γ in vivo.

In-body fibre optic imaging to go 3D

26 April 2019:

An advanced new method has been developed by CNBP researchers that may open the door to 3D microscopy in hard-to-reach areas of the human body.

It sees the successful miniaturization of a 3D imaging technique called ‘light field imaging’, taken to extreme new levels, making in-body application possible.

It could find significant application in diagnostic procedures called optical biopsies, where suspicious tissue is investigated during medical endoscopic procedures.

Reported in the journal ‘Science Advances’, project lead of the innovative imaging approach is Dr Antony Orth, Research Fellow at the RMIT University node of the CNBP (pictured).

The paper can be accessed below or read the media release here.

Journal: Science Advances.

Publication title: Optical fiber bundles: Ultra-slim light field imaging probes.

Authors: A. Orth, M. Ploschner, E. R. Wilson, I.S. Maksymov and B. C. Gibson.

Abstract: Optical fiber bundle microendoscopes are widely used for visualizing hard-to-reach areas of the human body. These ultrathin devices often forgo tunable focusing optics because of size constraints and are therefore limited to two-dimensional (2D) imaging modalities. Ideally, microendoscopes would record 3D information for accurate clinical and biological interpretation, without bulky optomechanical parts. Here, we demonstrate that the optical fiber bundles commonly used in microendoscopy are inherently sensitive to depth information. We use the mode structure within fiber bundle cores to extract the spatio-angular description of captured light rays—the light field—enabling digital refocusing, stereo visualization, and surface and depth mapping of microscopic scenes at the distal fiber tip. Our work opens a route for minimally invasive clinical microendoscopy using standard bare fiber bundle probes. Unlike coherent 3D multimode fiber imaging techniques, our incoherent approach is single shot and resilient to fiber bending, making it attractive for clinical adoption.

Below – Modal structure in optical fiber bundles captures light field information. Credit Antony Orth, RMIT University.

New method to functionalise glass fibers

17 April 2019:

One of the biggest challenges associated with exposed core glass optical fiber-based sensing is the availability of techniques that can be used to generate reproducible, homogeneous and stable surface coating. CNBP scientists report a one step, solvent free method for surface functionalization of exposed core glass optical fiber that allows for the binding of fluorophore-of-choice for metal ion sensing.

Lead author of the paper, published in the journal ‘Sensors’, is CNBP researcher Dr Akash Bachhuka based at the University of Adelaide.

Journal: Sensors

Publication TitleSurface Functionalization of Exposed Core Glass Optical Fiber for Metal Ion Sensing;

Authors: Akash Bachhuka, Sabrina Heng, Krasimir Vasilev, Roman Kostecki, Andrew Abell and Heike Ebendorff-Heidepriem

Abstract:

One of the biggest challenges associated with exposed core glass optical fiber-based sensing is the availability of techniques that can be used to generate reproducible, homogeneous and stable surface coating. We report a one step, solvent free method for surface functionalization of exposed core glass optical fiber that allows achieving binding of fluorophore of choice for metal ion sensing. The plasma polymerization-based method yielded a homogeneous, reproducible and stable coating, enabling high sensitivity aluminium ion sensing. The sensing platform reported in this manuscript is versatile and can be used to bind different sensing molecules opening new avenues for optical fiber-based sensing.

Binding mechanisms of solid-binding peptides

5 April 2019:

A new review article by CNBP PhD student Rachit Bansal and CNBP Associate Investigators (Anwar Sunna, Andrew Care and Tiffany Walsh) reports on experimental tools to study the binding mechanism of synthetic peptides to solid materials. The review provides insights into the role of these peptides as molecular building blocks for nanobiotechnology.

Journal: New Biotechnology.

Publication title: Experimental and theoretical tools to elucidate the binding mechanisms of solid-binding peptides.

Authors: Rachit Bansal, Andrew Care, Megan S. Lord, Tiffany R. Walsh, Anwar Sunna.

Abstract: The interactions between biomolecules and solid surfaces play an important role in designing new materials and applications which mimic nature. Recently, solid-binding peptides (SBPs) have emerged as potential molecular building blocks in nanobiotechnology. SBPs exhibit high selectivity and binding affinity towards a wide range of inorganic and organic materials. Although these peptides have been widely used in various applications, there is a need to understand the interaction mechanism between the peptide and its material substrate, which is challenging both experimentally and theoretically. This review describes the main characterisation techniques currently available to study SBP-surface interactions and their contribution to gain a better insight for designing new peptides for tailored binding.

Non-invasive assessment of islet cells

2 April 2019:

Professor Ewa Goldys, CNBP Deputy Director, UNSW Sydney,  in partnership with Associate Professor Shane Grey from the Garvan Institute have received an international grant from JDRC  for “Noninvasive assessment of islet cells”.

This project will develop a non-invasive method for real-time monitoring of encapsulated beta cells in vitro and in vivo.  This will help assess the fate of implanted cells and define the conditions required to produce high quality insulin-producing cells for implantation and their precursors.

The results will lay the foundations for in vivo assessment of islet transplantation success.

Henan University visit

Prof Jim Piper2 April 2019:

CNBP Chief Investigators at Macquarie University, Prof Jim Piper and Prof Nicole Packer, as well as CNBP Associate Investigator Dr Bingyang Shi have met with delegates from Henan University led by Prof. Yang Zhonghua, Deputy Vice Chancellor and Henan University Vice President.

Henan University, founded in 1912, is located in Kaifeng, China and is known globally for its strength in the Biology discipline. Discussed at the meeting were CNBP research areas and projects, as well as the potential for collaboration. Prof. Piper and Prof. Packer were invited to visit Henan University for further talks later in the year.

L to R – Prof Nicole Packer, Prof. Yang Zhonghua, Prof Jim Piper and Dr Bingyang Shi.