Speaker
Dr
sylvain bohic
(Inserm)
Description
Several essential metal ions participate in the control of numerous metabolic and signaling pathways, but their rich coordination chemistry and redox properties confer them a propensity to randomly coordinate and catalytically react inside the cell with protein sites other than those tailored for that purpose. Investigating metal homeostasis and its dysfunctions is crucial to better understand the cell functions and the influence on cellular pathology [1]. The associated challenge to analytical chemistry techniques, consists in locating and quantifying these elements, mostly present at trace level, within the highly complex intracellular landscape. As such, cutting-edge technique providing quantitative imaging for detailed study of elemental homeostasis or the intracellular distribution of metal-based drugs at biologically relevant concentration in a label-free fashion is highly desirable. The synchrotron X-ray fluorescence (XRF) nanoprobe as developed today provide the required sensitivity and spatial resolution to elucidating the 2D and 3D distribution, concentration of elements particularly metals inside entire cells at the organelle level. The new state-of-the-art Nano-Imaging beamline ID16A-NI at ESRF offers unique capabilities for X-ray imaging at nanometer scale delivering an extremely bright, nanofocused beam (> 5×1011ph/s at ∆λ/λ~10 2) at high energies (~30nm at 17kev [2]. X-ray tomography techniques offer the potential to image and quantify 'thick' cells and tissues in 3D without excessive sample preparation [3,4]. Recently, we reported the use of correlative synchrotron X-ray holographic and X-ray fluorescence nanotomography to quantify elemental 3D distribution within fixed or freeze-dried single cells [5] but also on frozen-hydrated cells. We will illustrate the capabilities of this techniques to provide quantitative nanoscopic cryo-XRF of cell as diverse as cancer cells exposed to organometallic drugs, neurons or cancer cells exposed to metal-based nanowires.
[1] Finney, L.A., O’halloran, T.V., Science (2003) 300, 931–936
[2] J. C. Da Silva et al, Optica (2017) 4, 492
[3] DeJonge, M.D. et al. PNAS (2010) 107, 15676–15680.
[4] Deng, J. et al. Science advances (2018) 4, eaau4548
[5] Yang, Y, et al. Analytical chemistry (2019) 91, 6549-6554.
Primary author
Dr
sylvain bohic
(Inserm)
Co-authors
Dr
Alexandra Pacureanu
(ESRF)
Dr
Murielle Salome
(ESRF)
Dr
Peter Cloetens
(ESRF)
Dr
Yang Yang
(NSLS-II)
Dr
julio cesar Da Silva
(CNRS)
