X-ray fluorescence microscopes offer the highest sensitivity for studies of the role of trace metals in cells, and they provide essential informatio for understanding the ultrastructural targeting of nanoparticles used for potential cancer therapies. With ARRA support from the NIH, co-PI Woloschak et al. have obtained the Bionanoprobe at Argonne's Advanced Photon Source (the nation's premier hard x-ray synchrotron light source facility). This is a first-of-its-kind instrument for x-ray fluorescence studies of trace elements in cells and tissue sections which offers a thousandfold improvement in sensitivity compared to electron microprobes, cryo transfer conditions to work with fully hydrated specimens at the highest preparation fidelity possible, and 3D tomographic imaging capabilities. Our proposal is to devote the scientific and technical effort needed to realize this new instrument's potential. Since hard x-ray microscopes are able to image samples with thicknesses ranging up to tens of micrometers, we can study whole cells and tissue sections in 3D in a way that electron microscopes cannot, and with a combination of sub-50 nm spatial resolution and sensitive trace element quantitation available in no other method. Cryogenic conditions are required to minimize radiation damage effects and maximize the fidelity of ultrastructure and trace element concentrations, so we need to develop and validate the novel cryogenic sample preparation methods appropriate for our unique sample types. X-ray fluorescence is relatively blind to the light elements (such as organic materials and water) that comprise nearly all the mass and ultrastructure of cells. Fortunately, we have pioneered several methods that can make visible what was once "dark," and we will develop a variant of these approaches (ptychography, a method of scanned coherent imaging that delivers quantitative phase contrast and spatial resolution beyond the limit of x-ray optics) and turn this into a routin, simultaneous-with-fluorescence imaging method for users of the Bionanoprobe. To validate these approaches and work from the beginning on a crucial biomedical research project, we will do this in the context of ongoing research in the use of DNA-conjugated nanoparticles containing titanium and/or gadolinium that are meant to target mitochondria for the treatment and imaging of prostrate, breast, and other cancers. In this way, we will develop the methods needed to fully realize the investment NIH has already made in the Bionanoprobe.
We will develop methods for preparing cryogenic biological specimens, and for combining high resolution phase contrast imaging with x-ray fluorescence imaging of trace elements. We will develop these capabilities along with research into nanoparticle-based drugs and labeling agents, to realize the full potential of a new, first-of-its-kind instrument.
|Mak, Rachel; Wild, Stefan M; Jacobsen, Chris (2016) Non-negative matrix analysis in x-ray spectromicroscopy: choosing regularizers. AIP Conf Proc 1696:|
|Deng, J; Vine, D J; Chen, S et al. (2016) Advances and challenges in cryo ptychography at the Advanced Photon Source. AIP Conf Proc 1696:|
|Colvin, Robert A; Jin, Qiaoling; Lai, Barry et al. (2016) Visualizing Metal Content and Intracellular Distribution in Primary Hippocampal Neurons with Synchrotron X-Ray Fluorescence. PLoS One 11:e0159582|
|Jin, Qiaoling; Vogt, Stefan; Lai, Barry et al. (2015) Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis. PLoS One 10:e0117437|
|Deng, Junjing; Vine, David J; Chen, Si et al. (2015) Opportunities and limitations for combined fly-scan ptychography and fluorescence microscopy. Proc SPIE Int Soc Opt Eng 9592:|
|Deng, Junjing; Nashed, Youssef S G; Chen, Si et al. (2015) Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging. Opt Express 23:5438-51|
|Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris et al. (2015) Optimizing detector geometry for trace element mapping by X-ray fluorescence. Ultramicroscopy 152:44-56|
|Hong, Young Pyo; Chen, Si; Jacobsen, Chris (2015) A New Workflow for x-ray fluorescence tomography: MAPSToTomoPy. Proc SPIE Int Soc Opt Eng 9592:|
|Deng, Junjing; Vine, David J; Chen, Si et al. (2015) Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae. Proc Natl Acad Sci U S A 112:2314-9|
|Chen, Si; Paunesku, Tatjana; Yuan, Ye et al. (2015) The Bionanoprobe: Synchrotron-based Hard X-ray Fluorescence Microscopy for 2D/3D Trace Element Mapping. Micros Today 23:26-29|
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