Category Archives: MQ

Reducing interference with cellular autofluorescence

14 March 2018:

CNBP Research Fellow Nicole Cordina is first author on a new study that reports on two novel methods for reducing interference with cellular autofluorescence for bio-imaging.

Journal: Scientific Reports.

Publication title: Reduced background autofluorescence for cell imaging using nanodiamonds and lanthanide chelates.

Authors: Nicole M. Cordina, Nima Sayyadi, Lindsay M. Parker, Arun Everest-Dass, Louise J. Brown & Nicolle H. Packer.

Abstract:
Bio-imaging is a key technique in tracking and monitoring important biological processes and fundamental biomolecular interactions, however the interference of background autofluorescence with targeted fluorophores is problematic for many bio-imaging applications. This study reports on two novel methods for reducing interference with cellular autofluorescence for bio-imaging. The first method uses fluorescent nanodiamonds (FNDs), containing nitrogen vacancy centers. FNDs emit at near-infrared wavelengths typically higher than most cellular autofluorescence; and when appropriately functionalized, can be used for background-free imaging of targeted biomolecules. The second method uses europium-chelating tags with long fluorescence lifetimes. These europium-chelating tags enhance background-free imaging due to the short fluorescent lifetimes of cellular autofluorescence. In this study, we used both methods to target E-selectin, a transmembrane glycoprotein that is activated by inflammation, to demonstrate background-free fluorescent staining in fixed endothelial cells. Our findings indicate that both FND and Europium based staining can improve fluorescent bio-imaging capabilities by reducing competition with cellular autofluorescence. 30 nm nanodiamonds coated with the E-selectin antibody was found to enable the most sensitive detective of E-selectin in inflamed cells, with a 40-fold increase in intensity detected.

Goldys on ‘Key Thinkers’ panel

8 February 2018:

The ability to develop a holistic and interdisciplinary vision was raised as a key attribute and skill by CNBP Deputy Director Prof Ewa Goldys at today’s ‘Key Thinkers – Key Concepts – Scholarly Gaze’ panel discussion, coordinated by the Faculty of Human Sciences, based at Macquarie University.

The event, consisting of prominent scientific speakers across differing disciplines, looked to better define the process of ‘seeing’ and ‘observation’ within the higher education research environment. Discussed were the use of technologies and techniques to help support advanced scientific theory development as well as best-practice methodology and laboratory experimentation.

Goldys, Professor at UNSW and Adjunct Professor at Macquarie University noted the advantages of having alternate vantage points and expertise from differing disciplines in her imaging, visualisation and cell colour research at the CNBP.

“It is the ability to bring together multiple disciplines and areas  – such as physics, chemistry, biology, medicine and materials science – that allows for the big science and health questions to be explored and then answered,” she said.

Below – Prof Ewa Goldys discussing the way in which she has successfully combined computer analysis with microscopy, to extract highly detailed cellular information that can help distinguish between healthy and diseased cells.

Sameera Iqbal awarded poster prize

2 February 2018:

Sameera Iqbal, CNBP PhD student at Macquarie University has been awarded a certificate and cash prize for her poster presentation at the Australasian Glycoscience Symposium at the Lorne Proteomics Conference, 2 Feb, 2018.

Her poster detailed the following work –

‘PolySialic Acid (PolySia) is an α2-8-linked sialic acid chain present on cell surfaces in embryonic brains. Changes in polysialylation pattern are reported to be associated with immune defense and inflammation in the CNS. Opioids such as Morphine-3-Glucuronide (M3G) (metabolite of morphine) activates neuroinflammation in a manner parallel to Lipopolysaccharide (LPS), compromising opioid-induced analgesia. In this study, morphine (Morphine-3-glucuronide) was hypothesized to affect the polySia expression in neurons and astrocyte cell lines. It was observed that PolySia expression was significantly increased in neurons following LPS and M3G stimulation.’

Well done Sameera!

New CNBP student at Macquarie

11 January 2018:

CNBP is happy to announce its newest student – Mina Ghanimi Fard. Mina is undertaking a Master of Research in Molecular Sciences at Macquarie University and is based in the Department of Chemistry and Biomolecular Sciences.

Supervised by CNBP’s Dr Lindsay Parker, her project title is ‘Targeting Sugar Receptors with Bio-conjugated Nanodiamonds in a 3D Model of Human Brain Cancer.’

Mina has a Bachelor Degree  of General Biology from Azad University in Iran and a Master of Managerial Psychology from HELP University in Malaysia.

Areas of interest include biotechnology in general and also cancer related research; fluorescent nanodiamonds and microscope imaging; CRISPER and synthetic biology or anything related to gene modification.

Welcome to the CNBP team Mina!

New unmixing method to detect and measure fluorophores

17 November 2017:

A new CNBP paper “Statistically strong label-free quantitative identification of native fluorophores in a biological sample,” by Saabah B. Mahbub (first author pictured), Martin Plöschner, Martin E. Gosnell, Ayad G. Anwer and Ewa M. Goldys has just been published in Scientific Reports and is available online.

This work addresses a genuine shortage of methods for real-time continuous monitoring of biochemistry of cells and tissues, especially live cells. Saabah Mahbub and team developed an automated and unbiased unmixing methodology to non-invasively detect the presence and spatial distributions of endogenous fluorophores in retina cells. The method was validated on artificial images, where the addition of a varying known level of noise has allowed to quantify the accuracy of spectral unmixing.

With its capability for high throughput, automation and embedded compatibility with statistical analysis this work will contribute to improved quantification and objectivity in biomedical research.

Microfluidic droplet extraction

16 November 2017:

CNBP and Macquarie University PhD candidate Shilun Feng is first author on a new paper exploring a ‘membrane-on-a-chip’ device. The technology has the potential to form an integral part of a new type of microneedle that would be able to transport tiny and precise amounts of fluid/medication within the body.

Journal: Micromachines.

Publication titleMicrofluidic Droplet Extraction by Hydrophilic Membrane.

Authors: Shilun Feng, Micheal N. Nguyen, and David W. Inglis.

Abstract: Droplet-based microfluidics are capable of transporting very small amounts of fluid over long distances. This characteristic may be applied to conventional fluid delivery using needles if droplets can be reliably expelled from a microfluidic channel. In this paper, we demonstrate a system for the extraction of water droplets from an oil-phase in a polymer microfluidic device. A hydrophilic membrane with a strong preference for water over oil is integrated into a droplet microfluidic system and observed to allow the passage of the transported aqueous phase droplets while blocking the continuous phase. The oil breakthrough pressure of the membrane was observed to be 250 ± 20 kPa, a much greater pressure than anywhere within the microfluidic channel, thereby eliminating the possibility that oil will leak from the microchannel, a critical parameter if droplet transport is to be used in needle-based drug delivery.

New CNBP PhD student

Jagjit Kaur15 November 2017:

CNBP welcomes its latest PhD student Jagjit Kaur who will study under the supervision of CNBP researcher Dr Guozhen Liu at Macquarie University.

Jagjit has recently joined Macquarie University from India to pursue her research which will be focused on the development of nanoelectrodes for single cell analysis.

The main aim of her project is to develop nanotools that will be used for real time monitoring of cell secretions by single cells. The research outcome of this project will be expected to be useful for understanding cell-to-cell communication.

Previously, Jagjit has completed her undergraduate and masters degrees from Punjabi University, India in Biotechnology. Her masters dissertation was based on development of biosensors for detection of asparagine levels in leukemic samples.

Welcome to the CNBP team Jagjit!

DECRA awarded to Centre Research Fellow

13 November 2017:

Congratulations to Dr Lindsay Parker, CNBP Research Fellow at Macquarie University who has just been granted a Discovery Early Career Researcher Award (DECRA) from the Australian Research Council (ARC).

The award will support the following research activity:

“Intelligently linking nanoscience to neuroscience with glycan biology. This project aims to provide a comprehensive description of the unique cell-surface glycan expression on inflamed neurons, astrocytes, microglia and oligodendrocytes. This project will use glycan profiling data to engineer luminescent nanoparticles with superior neuroimaging qualities for cell type-specific in vivo targeting and drug delivery in the central nervous system. The project outcomes are expected to improve our fundamental understanding of neurobiological cell-surfaces.”

Information on successful DECRA grants can be accessed on the ARC website here.

Cytokine detection

6 November 2017:

New research from CNBP scientists reports on a cytokine sensor – fabricated on the surface of an optical fibre. Cytokines are molecules that play a critical role in cellular response to infection, inflammation, trauma and disease. Lead author on the paper, published in the journal ‘Biosensors and Bioelectronics’, is Centre PhD student Kaixin Zhang who is based at Macquarie University.

Journal: Biosensors and Bioelectronics.

Publication title: Robust immunosensing system based on biotinstreptavidin coupling for spatially localized femtogram mL−1 level detection of interleukin-6.

Authors: Kaixin Zhang, Guozhen Liu, Ewa M. Goldys.

Abstract: Detection of a very low amount of cytokines such as interleukin-6 (IL-6) in clinical fluids is important in biomedical research and clinical applications. Here, we demonstrate spatially-localised ultrasensitive (femtogram mL−1) level detection of IL-6 in serum and in cell culture media. Our approach is based on a sandwich immunosensor fabricated on the surface of an optical fibre. Firstly, the biotinylated IL-6 capture antibody was immobilized on the fibre surface by biotin-streptavidin coupling. Then the fabricated fibre was used for capturing IL-6 followed by exposure to detection antibody which was labeled with the fluorescent magnetic nanoparticles to report the signal. A linear relationship between IL-6 concentration and the fluorescence signal was obtained in the range from 0.4 pg mL−1 to 400 pg mL−1 of IL-6, with the limit of detection down to 0.1 pg mL−1. In addition, this optical fibre sensor was successfully applied for the localized detection of IL-6 with the spatial resolution of 200 µm and a sample volume of 1 μL. Finally, the performance of the fibre sensor was demonstrated by detection of IL-6 secreted by BV-2 cells with comparable performance of the conventional enzyme-linked immunosorbent assay (ELISA).