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.
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%.
5 December 2016:
A new publication from CNBP researchers (lead author Philipp Reineck pictured) demonstrates bright and photostable fluorescence from nitrogen-vacancy centers in unprocessed nanodiamond particle aggregates. The work has just been reported in the journal ‘Nanoscale’ and is accessible online.
Title: Bright and photostable nitrogen-vacancy fluorescence from unprocessed detonation nanodiamond.
Authors: P. Reineck, M. Capelli, D. W. M. Lau, J. Jeske, M. R. Field, T. Ohshim, A. D. Greentree and B. C. Gibson.
Abstract: Bright and photostable fluorescence from nitrogen-vacancy (NV) centers is demonstrated in unprocessed detonation nanodiamond particle aggregates. The optical properties of these particles is analyzed using confocal fluorescence microscopy and spectroscopy, time resolved fluorescence decay measurements, and optically detected magnetic resonance experiments. Two particle populations with distinct optical properties are identified and compared to high-pressure high-temperature (HPHT) fluorescent
nanodiamonds. We find that the brightness of one detonation nanodiamond particle population is on the same order as that of highly processed fluorescent 100 nm HPHT nanodiamonds. Our results may open the path to a simple and up-scalable route for
the production of fluorescent NV nanodiamonds for use in bioimaging applications.
30 November 2016:
Exciting translational work by CNBP researchers (project leader Dr Erik Schartner pictured left) has resulted in the development of an optical fibre probe that distinguishes breast cancer tissue from normal tissue – potentially allowing surgeons to be much more precise when removing breast cancer. The work has just been reported in the journal ‘Cancer Research’ and is accessible online.
Journal: Cancer Research.
Title: Cancer Detection in Human Tissue Samples Using a Fiber-Tip pH Probe.
Authors: Erik P. Schartner, Matthew R. Henderson, Malcolm Purdey, Deepak Dhatrak, Tanya M. Monro, P. Grantley Gill and David F. Callen.
Intraoperative detection of tumorous tissue is an important unresolved issue for cancer surgery. Difficulty in differentiating between tissue types commonly results in the requirement for additional surgeries to excise unremoved cancer tissue or alternatively in the removal of excess amounts of healthy tissue. Although pathologic methods exist to determine tissue type during surgery, these methods can compromise postoperative pathology, have a lag of minutes to hours before the surgeon receives the results of the tissue analysis, and are restricted to excised tissue. In this work, we report the development of an optical fiber probe that could potentially find use as an aid for margin detection during surgery. A fluorophore-doped polymer coating is deposited on the tip of an optical fiber, which can then be used to record the pH by monitoring the emission spectra from this dye. By measuring the tissue pH and comparing with the values from regular tissue, the tissue type can be determined quickly and accurately. The use of a novel lift-and-measure technique allows for these measurements to be performed without influence from the inherent autofluorescence that commonly affects fluorescence-based measurements on biological samples. The probe developed here shows strong potential for use during surgery, as the probe design can be readily adapted to a low-cost portable configuration, which could find use in the operating theater. Use of this probe in surgery either on excised or in vivo tissue has the potential to improve success rates for complete removal of cancers.
29 November 2016:
CNBP researchers (lead author Jingxian Yu pictured), have published a paper exploring the quantum interference effects on electronic transport in peptides. The work has just been reported in the journal ‘Molecular Systems Design & Engineering’ and is accessible online.
Journal: Molecular Systems Design & Engineering.
Title: Exploiting the interplay of quantum interference and backbone rigidity on electronic transport in peptides: A step towards bio-inspired quantum interferometers.
Authors: Jingxian Yu, John R Horsley and Andrew D Abell.
Abstract: Electron transfer in peptides provides an opportunity to mimic nature for applications in bio-inspired molecular electronics. However, quantum interference effects, which become significant at the molecular level, have yet to be addressed in this context. Electrochemical and theoretical studies are reported on a series of cyclic and linear peptides of both β-strand and helical conformation, to address this shortfall and further realize the potential of peptides in molecular electronics. The introduction of a side-bridge into the peptides provides both additional rigidity to the backbone, and an alternative pathway for electron transport. Electronic transport studies reveal an interplay between quantum interference and vibrational fluctuations. We utilize these findings to demonstrate two distinctive peptide-based quantum interferometers, one exploiting the tunable effects of quantum interference (β-strand) and the other regulating the interplay between the two phenomena (310-helix).
24 November 2016:
In this latest paper, CNBP researchers (lead author Wei Deng pictured left) developed PLGA nanocomposites by incorporating a photosensitizer, verteporfin and gold nanoparticles into the polymeric matrix and utilised them for enhanced photodynamic therapy of cancer cells.
Journal: RSC Advances.
Title: PLGA nanocomposites loaded with verteporfin and gold nanoparticles for enhanced photodynamic therapy of cancer cells.
Authors: Wei Deng, Zofia Kautzka, Wenjie Chen and Ewa M Goldys.
Abstract: In this paper, PLGA nanocomposites were developed by incorporating a photosensitizer, verteporfin and gold nanoparticles into the polymeric matrix and utilised for enhanced photodynamic therapy of cancer cells. Both enhanced fluorescence and O2 generation from verteporfin were observed in this new formulation under both 425 nm LED and 405 nm laser illumination. A maximum enhancement factor of 2.5 for fluorescence and 1.84 for O2 generation was obtained when the molar ratio of gold : VP was 5:1 and excited at 425 nm, compared with PLGA doped with verteporfin alone. The experiment results could be explained by the local electric field enhancement of gold nanoparticles. Furthermore, improved therapeutic efficacy in human pancreatic cancer cells, PANC-1, was also demonstrated by using this new formulation following light exposure, indicating the utility of these nanocomposites for enhanced photodynamic therapy.
The paper is accessible online.
22 November 2016:
CNBP researchers (CNBP CI Nicki Packer pictured) are coauthors on an exciting new paper reporting on the design and development of upconversion immune-nanohybrids (UINBs) that have demonstrated potential for prostate cancer cell diagnostic detection.
Journal: Scientific Reports.
Title: Stable Upconversion Nanohybrid Particles for Specific Prostate Cancer Cell Immunodetection.
Authors: Yu Shi, Bingyang Shi, Arun V Everest Dass, Yiqing Lu, Nima Sayyadi, Liisa Kautto, Robert D Willows, Roger Chung, James Piper, Helena Nevalainen, Bradley Walsh, Dayong Jin and Nicolle H Packer.
Abstract: Prostate cancer is one of the male killing diseases and early detection of prostate cancer is the key for better treatment and lower cost. However, the number of prostate cancer cells is low at the early stage, so it is very challenging to detect. In this study, we successfully designed and developed upconversion immune-nanohybrids (UINBs) with sustainable stability in a physiological environment, stable optical properties and highly specific targeting capability for early-stage prostate cancer cell detection. The developed UINBs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS) and luminescence spectroscopy. The targeting function of the biotinylated antibody nanohybrids were confirmed by immunofluorescence assay and western blot analysis. The UINB system is able to specifically detect prostate cancer cells with stable and background-free luminescent signals for highly sensitive prostate cancer cell detection. This work demonstrates a versatile strategy to develop UCNPs based sustainably stable UINBs for sensitive diseased cell detection.
The paper is accessible online.
22 November 2016:
Failure to launch: aberrant cumulus gene expression during oocyte in vitro maturation
Hannah M Brown, Kylie R Dunning, Melanie Sutton-McDowall, Robert B Gilchrist,
Jeremy G Thompson and Darryl L Russell
In vitro maturation (IVM) offers significant benefits for human infertility treatment and animal breeding, but this potential is yet to be
fully realised due to reduced oocyte developmental competence in comparison with in vivo matured oocytes. Cumulus cells occupy
an essential position in determining oocyte developmental competence. Here we have examined the areas of deficient gene
expression, as determined within microarrays primarily from cumulus cells of mouse COCs, but also other species, between in vivo
matured and in vitro matured oocytes. By retrospectively analysing the literature, directed by focussing on downregulated genes, we
provide an insight as to why the in vitro cumulus cells fail to support full oocyte potential and dissect molecular pathways that have
important roles in oocyte competence. We conclude that the roles of epidermal growth factor signalling, the expanded extracellular
matrix, cumulus cell metabolism and the immune system are critical deficiencies in cumulus cells of IVM COCs.
10 November 2016:
In this latest review paper, CNBP researchers Xiaozhou (Michelle) Zhang (pictured left) and Prof Andrew Abell explore the preparation and properties of peptide-based macrocycles that target important therapeutic aims for conditions such as cancer, cataract, HIV, and neurological diseases.
Journal: Australian Journal of Chemistry.
Title: Macrocyclic Peptidomimetics Prepared by Ring-Closing Metathesis and Azide-Alkyne Cycloaddition.
Authors: Ashok D Pehere, Xiaozhou Zyhang and Andrew D Abell.
Abstract: Macrocycles are finding increasing use as a means to define the backbone geometries of peptides and peptidomimetics.Ring-closing metathesis and CuI-catalyzed azide–alkyne cycloaddition are particularly useful for introducing such rings and they do so in high yield and with a good functional group tolerance and compatibility. Here, we present an overview of the use of these two methods, with reference to selected examples and particular reference to b-strand peptidomimetics for use as protease inhibitors.
The paper is accessible online.
9 November 2016:
Investigation of optical coherence microelastography as a method to visualize micro-architecture in human axillary lymph nodes;
Kelsey M. Kennedy, Lixin Chin, Philip Wijesinghe, Robert A. McLaughlin, Bruce Latham, David D. Sampson, Christobel M. Saunders and Brendan F. Kennedy
BMC Cancer; DOI 10.1186/s12885-016-2911-z.