Category Archives: MQ

Engineering protein-based nanoparticles

23 July 2018:

A new review paper has been published in the journal ‘Genes’ featuring two CNBP Associate Investigators as co-authors, Dr Andrew Care (Cancer Institute NSW) and Dr Anwar Sunna (Macquarie University).

Titled, ‘Bioengineering Strategies for Protein-based Nanoparticles’, the paper focuses on the tools available to custom-engineer protein-based nanoparticles for different applications, including those in nanomedicine and biotechnology.

First author of the paper, and co-supervised by Dr Care and Dr Sunna is Ms Dennis Diaz (pictured left in photo).

Journal: Genes.

Publication title: Bioengineering Strategies for Protein-Based Nanoparticles.

Authors: Dennis Diaz, Andrew Care and Anwar Sunna.

Abstract: In recent years, the practical application of protein-based nanoparticles (PNPs) has expanded rapidly into areas like drug delivery, vaccine development, and biocatalysis. PNPs possess unique features that make them attractive as potential platforms for a variety of nanobiotechnological applications. They self-assemble from multiple protein subunits into hollow monodisperse structures; they are highly stable, biocompatible, and biodegradable; and their external components and encapsulation properties can be readily manipulated by chemical or genetic strategies. Moreover, their complex and perfect symmetry have motivated researchers to mimic their properties in order to create de novo protein assemblies. This review focuses on recent advances in the bioengineering and bioconjugation of PNPs and the implementation of synthetic biology concepts to exploit and enhance PNP’s intrinsic properties and to impart them with novel functionalities.

A photoresponsive LPD system developed

19 July 2018:

CNBP researchers have published a paper reporting on  the development of a novel photoresponsive liposome-polycation-DNA (LPD) platform. Lead author on the paper was Wenjie Chen (pictured).

Journal: Journal of Materials Chemistry B.

Publication title: Photoresponsive endosomal escape enhances gene delivery using liposome-polycation-DNA (LPD) nanovector.

Authors: Wenjie Chen, Wei Deng, Xin Xu, Xiang Zhao, Jenny Nhu Vo, Ayad G. Anwer, Thomas C. Williams, Haixin Cui, Ewa M. Goldys.

Abstract: Lipid-based nanocarriers with stimuli responsiveness have been utilized as controlled release systems for gene/drug delivery applications. In our work, by taking advantage of high complexation capbility of polycations and the light triggered property, we designed a novel photoresponsive liposome-polycation-DNA (LPD) platform. This LPD carrier incorporates verteporfin (VP) in lipid bilayers and the complex of polyethylenimine (PEI)/plasmid DNA (pDNA) encoding EGFP (polyplex) in the central cavities of liposomes. The liposomes were formulated with cationic lipids, PEGylated neutral lipids and cholesterol molecules, which improve their stability and cellular uptake in the serum-containing media. We evaluated the nanocomplex stability by monitoring size changes over six days, and the celluar uptake of nanocomplex by imaging the intracellular route. We also demonstrated light triggered the cytoplasmic release of pDNA upon irradiation with a 690 nm LED light source. Furthermore this light triggered mechanism has been studied at subcellular level. The activated release is driven by the generation of reactive oxygen species (ROS) from VP after light illumination. These ROS oxidize and destabilize the liposomal and endolysosomal membranes, leading to the release of pDNA into the cytosol and subsequent gene transfer activities. Light-triggered endolysosomal escape of pDNA at different time points was confirmed by quantitative analysis of colocalization between pDNA and endolysosomes. The increased expression of the reporter EGFP in human colorectal cancer cells was also quantified after light illumination at various time points. The efficiency of this photo-induced gene transfection was demonstrated to be more than double compared to non-irradiated controls. Additionally, we observed reduced cytotoxicity of the LPDs compared with the polyplexes alone. This study have thus shown that light-triggered and biocompatible LPDs enable improved control of efficient gene delivery which will be beneficial for future gene therapies.

X-ray triggered nano-bubbles to target cancer

13 July 2018:

Innovative drug filled nano-bubbles, able to be successfully triggered in the body by X-rays, have been developed by CNBP and Macquarie University researchers, paving the way for a new range of cancer treatments for patients.

The tiny bubbles, known as liposomes, are commonly used in pharmacology to encapsulate drugs, making them more effective in the treatment of disease. Researchers have now been able to engineer these liposomes to discharge their drug cargo on-demand, once activated by standard X-rays. Initial testing has shown this technique to be highly efficient in killing bowel cancer cells.

“The development and application of various nanomaterial designs for drug delivery is currently a key focus area in nanomedicine,” says lead author of the research Dr Wei Deng (pictured), Associate Investigator at the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) and scientist at Macquarie University when the research was undertaken.

“Liposomes are already well established as an extremely effective drug-delivery system. Made out of similar material as cell membranes, these ‘bubbles’ are relatively simple to prepare, can be filled with appropriate medications and then injected into specific parts of the body. The issue however, is in controlling the timely release of the drug from the liposome,” she says.

“We have ensured that the liposomes release their drug pay-load at exactly the right time and in exactly the right place to ensure the most effective treatment. One way of doing this is to trigger the collapse of the liposome when and where it is needed. Our X-ray triggerable liposomes allow this on-demand drug-release to occur,” says Dr Wei Deng.

“The approach we took was to embed gold nanoparticles and the photo-sensitive molecule verteporfin into the wall of the liposome.”

“The radiation from the X-ray causes the verteporfin to react and to produce highly reactive singlet oxygen which then destabilises the liposomal membrane, causing the release of the drug,” says Dr Wei Deng.

“The gold nanoparticles are added into the mix as they focus the X-ray energy. This enhances the singlet oxygen generation and hence improves the speed of the membrane breakup”, she says.

Read the full media release here.

Journal: Nature Communications.

Publication title: Controlled gene and drug release from a liposomal delivery platform triggered by X-ray radiation.

Authors: Wei Deng, Wenjie Chen, Sandhya Clement, Anna Guller, Zhenjun Zhao, Alexander Engel & Ewa M. Goldys.

Below – Dr Wei Deng.

Research translation is focus of CNBP workshop

11 July 2018:

The take-home message from CNBP’s two day ‘Research Translation’ workshop, held in Adelaide, the 5th and 6th of July, was that high quality science can change people’s lives and that the research that CNBP undertakes is truly transformative with huge translation potential.

Over 75 CNBP researchers, students, partners and invited guests attended the workshop which was based at the University of Adelaide on Day One and which then moved to the South Australian Health and Medical Research Institution (SAHMRI) on Day Two.

During the workshop CNBP researchers worked in small groups with senior clinicians to learn about clinical problems and discuss how their research could be translated. They also heard from several leading clinicians about what it’s like to be part of a clinical translation project.

Additional talks described clinical translation from ‘the other side’ – with technical researchers explaining the steps involved in translating a new technology, and drawing on their real-world experiences and outlining key learnings that had been made. Dr Anne Collins then brought insight from a commercial perspective, providing a detailed case study of one of Trajan Scientific and Medical’s most recent market products.

A number of CNBP researchers, from all nodes across the Centre, then presented brief updates on clinically-related projects that are currently underway. This culminated in a master-class led and coordinated by CNBP CI Nicki Packer on seeing nanoparticles at super resolution in cells.

CNBP Director Prof Mark Hutchinson wrapped-up workshop proceedings noting that he had been highly impressed with the science and information presented and encouraged the CNBP team to keep ‘commercialisation impact’ top of mind as this was one of the Centre’s core values.

Prof Rob McLaughlin, Founder of Miniprobes and Senior CNBP Investigator, who helped host the event noted, “We’d like express our gratitude to all of the clinicians who made the workshop such a success: Jillian Clark, Rob Fitridge, Adam Wells, Phan Nguyen, Nam Nguyen, Tarik Sammour, Hidde Kroon, Sam Parvar and Nagendra Dudi-Venkata. Our thanks also to Anne Collins from Trajan Scientific and Medical, and Andrew Abell.”

Informal feedback from attendees at the event was that they had experienced a highly informative and rewarding two days of translational workshop activity.

Note – a brief visual video of the event has been produced by Dr Johan Verjans here.

Below – Dr Johan Verjans CNBP AI at SAHMRI discusses the need to work closely with clinicians to successfully translate research into the clinical environment.

New X-ray-induced photodynamic therapy system

19 June 2018:

Researchers from CNBP have developed an X-ray-induced photodynamic therapy (PDT) system where nanoparticles incorporating a photosensitizer, verteporfin, were triggered by X-ray radiation to generate cytotoxic singlet oxygen. This system offers the possibility of enhancing the radiation therapy commonly prescribed for the treatment of cancer by simultaneous PDT.

Lead author on the paper was Dr Sandhya Clement (pictured).

Journal: International Journal of Nanomedicine.

Publication title: X-ray radiation-induced and targeted photodynamic therapy with folic acid-conjugated biodegradable nanoconstructs.

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

Abstract:
Introduction: The depth limitation of conventional photodynamic therapy (PDT) with visible electromagnetic radiation represents a challenge for the treatment of deep-seated tumors. Materials and methods: To overcome this issue, we developed an X-ray-induced PDT system where poly(lactide-co-glycolide) (PLGA) polymeric nanoparticles (NPs) incorporating a photosensitizer (PS), verteporfin (VP), were triggered by 6 MeV X-ray radiation to generate cytotoxic singlet oxygen. The X-ray radiation used in this study allows this system to breakthrough the PDT depth barrier due to excellent penetration of 6 MeV X-ray radiation through biological tissue. In addition, the conjugation of our NPs with folic acid moieties enables specific targeting of HCT116 cancer cells that overexpress the folate receptors. We carried out physiochemical characterization of PLGA NPs, such as size distribution, zeta potential, morphology and in vitro release of VP. Cellular uptake activity and cell-killing effect of these NPs were also evaluated. Results and discussion: Our results indicate that our nanoconstructs triggered by 6 MeV X-ray radiation yield enhanced PDT efficacy compared with the radiation alone. We attributed the X-ray-induced singlet oxygen generation from the PS, VP, to photoexcitation by Cherenkov radiation and/or reactive oxygen species generation facilitated by energetic secondary electrons produced in the tissue. Conclusion: The cytotoxic effect caused by VP offers the possibility of enhancing the radiation therapy commonly prescribed for the treatment of cancer by simultaneous PDT.

 

CNBP science gets fresh

6 June 2018:

CNBP researcher Dr Annemarie Nadort has participated in ‘Fresh Science’, a national competition helping early-career researchers find, and then share, their stories of discovery. The program takes up-and-coming researchers with no media experience and turns them into spokespeople for science, giving them media training and a public event to present their science to the community. Ten researchers took part in the Fresh Science event for NSW.

Dr Nadort reports on her experience below.

“Fresh Science was an intense, colourful, and informative workshop ranging between fun and hard work. The first day consisted of a Q&A and mock interviews with journalists from television, radio and written news. The participants all had very interesting and new science to pitch and I definitely enhanced my network of Sydney researchers.”

“I also was impressed by the skills of the journalists. They said that society viewed them as the least trusted people, but their professionalism and ability to pick up the most important parts of our complicated science made me think the opposite!”

“The second morning consisted of a Q&A with commercialisation experts, the NSW Chief Scientist and collaboration experts, followed by a 1 minute pitch to stakeholders.”

“The workshop concluded with a final event at the Three Wise Monkeys Hotel: every Fresh Scientist presented their research for as long as their sparkler was still sparkling.”

“I was awarded the ‘highly commended’ distinction for my ‘bright sparks’ presentation which detailed the development of optical methods to improve the detection and therapy of high-grade brain cancer.”

Below – Dr Annemarie Nadort presents her science to an interested and engaged audience at the Three Wise Monkeys Hotel, Sydney.

CNBP outreach at MQ ‘Career Ready Day’

10 May 2018:

CNBP’s Dr Annemarie Nadort has shone a light on biophotonics, microcirculation, medical device development and a career in science to an audience of 35 Yr 9-10 high school students, at an outreach session at Macquarie University, May 10th, 2018.

The students, attending the University as a part of a ‘career-ready’ day, were given a quick tutorial on blood and light and were then given a hands-on demonstration of a clinical microcirculation imager that was able to provide a real-time view of red blood cells circulating in capillaries under the tongue.

Students were then given a brief history of the imager’s development and then asked how they could potentially improve a mark-two version of the device from a biological, physics, engineering, IT and software perspective. This explained Dr Nadort was the sort of critical thinking required to kick-start a career in medical device design and development; and the skills that could be learnt from undertaking higher education study.

Feedback from the students was extremely positive. Half a dozen students tried the imager under their own tongues. Seeing the body’s cells operate in real-time on a large screen proved insightful and engaging to all in the room.

Below – Dr Annemarie Nadort explains to students how we can use light to see blood using innovative new tools and techniques.

Detecting zearalenone (a toxin found in cereals)

1 May 2018:

CNBP PhD student at Macquarie University, Fuyuan Zhang (pictured), is first author on a new paper reporting on the development of magnetic nanobead based fluoroimmunoassays  for detection of zearalenone (a toxin found in cereals).

Journal: Sensors and Actuators B: Chemical.

Publication title: Novel magnetic nanobeads-based fluoroimmunoassays for zearalenone detection in cereals using protein G as the recognition linker.

Authors: Fuyuan Zhang, Bing Liu, Guozhen Liu, Wei Sheng, Yan Zhang, Qi Liu, Shuo Wang.

Abstract: Zearalenone (ZEN) is a type of estrogenic mycotoxin commonly found in cereals. In order to satisfy the need for ultrasensitive detection of ZEN, we developed two novel magnetic nanobeads (MNBs)-based fluoroimmunoassays using protein G (PG) as recognition binder on the sensing interface. One proposed facile strategy is based on a first capture last react (FCLR) procedure while the other is a first react last capture (FRLC) format. Specifically, CdTe/CdS/ZnS quantum dots were synthesized and modified to antigen (OVA-ZEN) as the signal probes. The PG modified MNBs specifically captured the fragment crystallizable region of immunoglobulin G (IgG) with a level of orientation while avoiding the destruction of antibody’s binding sites caused by chemical coupling. Under the optimized conditions, the detection limits of 0.019 ng mL−1 and 0.049 ng mL−1 in the extract solution were obtained for the FCLR and FRLC, respectively. Furthermore, the established methods proved to be successful in detecting ZEN in real cereal samples with the detection limits being 0.6 μg kg−1 and 1.5 μg kg−1 in the FCLR and FRLC, respectively. The performance of the proposed assays was evaluated utilizing commercial ELISA kits with satisfactory results.

New CNBP review paper on SERS

23 April 2018:

CNBP researchers have  published a new review paper on surface enhanced Raman scattering (SERS), reporting on recent developments and applications, and in particular examining SERS nanotags in biosensing and bioimaging, describing case studies in which differing types of biomarkers have been investigated. Lead author on the paper was Wei Zhang from Macquarie University.

Journal: Journal of Analysis and Testing.

Publication title: SERS Nanotags and Their Applications in Biosensing and Bioimaging.

Authors: Wei Zhang, Lianmei Jiang, James A. Piper, Yuling Wang.

Abstract: Owing to the unique advantages of surface enhanced Raman scattering (SERS) in high sensitivity, specifcity, multiplexing capability and photostability, it has been widely used in many applications, among which SERS biosensing and bioimaging are the focus in recent years. The successful applications of SERS for non-invasive biomarker detection and bioimaging under in vitro, in vivo and ex vivo conditions, ofer signifcant clinical  information to improve diagnostic and prognostic outcomes. This review provides recent developments and applications of SERS, in particular SERS nanotags in biosensing
and bioimaging, describing case studies in which diferent types of biomarkers have been investigated, as well as outlining future challenges that need to be addressed before SERS sees both pathological and clinical use.