Browsing by Author "Cameron, M"

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    Gd-TPP-DOTA reduces cell viability in cancer cells via synchrotron radiotherapy
    (Australian National University, 2021-08-24) Middleton, RJ; Howell, NR; Livio, E; Wyatt, NA; Chacon, A; Fraser, BH; Barnes, M; Cameron, M; Rendina, LM; Häusermann, D; Lerch, M; Safavi-Naeini, M
    High-Z elements have been proposed as radiosensitisers in X-ray photon radiotherapy due to their emission of multiple high-LET photo- and Auger electrons following X-ray irradiation. Gadolinium is a particularly attractive candidate radiosensitiser, since it can also be used as an MRI contrast agent. In this study, we report on the efficacy of Gd-triphenylphosphonium salt-DOTA (Gd(III)-TPP-DOTA) for synchrotron microbeam radiation therapy dose enhancement. The compound utilises the mitochondrial targeting moiety triphenylphosphonium (TPP) to accumulate Gd in the inner mitochondrial membrane. Experiments were conducted using the dynamic mode option at hutch 2B of the Imaging and Medical Beamline at the Australian Synchrotron. Human glioblastoma multiforme cells (T98G cell line) were cultured to 80-90% confluence in T12.5 flasks. Approximately 24 hours prior to irradiation, the cultures were either treated with a 500 μM solution of Gd(III)DOTA-TPP or a vehicle control. Spatial dose distribution of synchrotron broad beam (BB) and single/multiple microbeams were measured using a micron-scale X-Tream dosimetry system and Gafchromic films in air and at 2 cm depth in solid water (same depth as the monolayer of cells in T12.5 flasks). A total of 96 flasks were irradiated, with doses of 0, 1, 2, 3, 4, 5, 10 and 16 Gy delivered in valley (MRT) or uniformly (BB). Post irradiation, each flask was re-seeded into 7 x 96 well-plates to perform the resazurin cell proliferation assay up to 7 days after irradiation. Our preliminary analysis indicates that for cells irradiated by 3 Gy of BB or MRT radiation, the addition of Gd(III)DOTA-TPP results in a reduction in viable cell mass by 24.25% and 25.79%, respectively, compared with untreated flasks. © The Authors
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    Towards sustainable environmental quality: priority research questions for the Australasian region of Oceania
    (John Wiley & Sons, Inc, 2019-07-05) Gaw, S; Harford, A; Pettigrove, VJ; Sevicke-Jones, G; Manning, T; Ataria, J; Cresswell, T; Dafforn, KA; Leusch, FDL; Moggridge, B; Cameron, M; Chapman, J; Coates, G; Colville, A; Death, C; Hageman, K; Hassell, KL; Hoak, M; Gadd, JB; Jolley, DF; Karami, A; Kotzakoulakis, K; Lim, R; McRae, N; Metzeling, L; Mooney, T; Myers, J; Pearson, A; Saaristo, M; Sharley, D; Stuthe, J; Sutherland, O; Thomas, O; Tremblay, L; Wood, W; Boxall, ABA; Rudd, MA; Brooks, BW
    Environmental challenges persist across the world, including the Australasian region of Oceania, where biodiversity hotspots and unique ecosystems such as the Great Barrier Reef are common. These systems are routinely affected by multiple stressors from anthropogenic activities, and increasingly influenced by global megatrends (e.g., the food–energy–water nexus, demographic transitions to cities) and climate change. Here we report priority research questions from the Global Horizon Scanning Project, which aimed to identify, prioritize, and advance environmental quality research needs from an Australasian perspective, within a global context. We employed a transparent and inclusive process of soliciting key questions from Australasian members of the Society of Environmental Toxicology and Chemistry. Following submission of 78 questions, 20 priority research questions were identified during an expert workshop in Nelson, New Zealand. These research questions covered a range of issues of global relevance, including research needed to more closely integrate ecotoxicology and ecology for the protection of ecosystems, increase flexibility for prioritizing chemical substances currently in commerce, understand the impacts of complex mixtures and multiple stressors, and define environmental quality and ecosystem integrity of temporary waters. Some questions have specific relevance to Australasia, particularly the uncertainties associated with using toxicity data from exotic species to protect unique indigenous species. Several related priority questions deal with the theme of how widely international ecotoxicological data and databases can be applied to regional ecosystems. Other timely questions, which focus on improving predictive chemistry and toxicology tools and techniques, will be important to answer several of the priority questions identified here. Another important question raised was how to protect local cultural and social values and maintain indigenous engagement during problem formulation and identification of ecosystem protection goals. Addressing these questions will be challenging, but doing so promises to advance environmental sustainability in Oceania and globally. © 2019 The Authors