| AVS 65th International Symposium & Exhibition | |
| Industrial Physics Forum | Tuesday Sessions |
| Session IPF+AS+BI+MN-TuM |
| Session: | Advanced Imaging and Structure Determination of Biomaterials |
| Presenter: | Jan-David Nicolas, University of Göttingen, Germany |
| Authors: | J.-D. Nicolas, University of Göttingen, Germany T. Salditt, University of Göttingen, Germany |
| Correspondent: | Click to Email |
X-rays deeply penetrate matter and thus provide information about the functional (interior) architecture of complex samples, from biological tissues and cells to novel composite materials. However, this potential of hard x-rays in view of penetration power, high spatial resolution, quantitative contrast, and compatibility with environmental conditions has to date not been fully developed, mainly due to significant challenges in x-ray optics. With the advent of highly brilliant radiation, coherent focusing, and lensless diffractive imaging this situation has changed. We show how nano-focused hard x-rays can be used for scanning as well as for full field holographic x-ray imaging of biological samples [1]. The central challenge of inverting the coherent diffraction pattern will be discussed and different reconstruction algorithms will be presented, from holographic techniques [2] to ptychography [3,4]. Next, we will present new approaches to treat the massive diffraction data recorded in scanning nano-diffraction experiments of cells and tissues [5].
By scanning the sample through the focused x-ray beam and recording full diffraction patterns in each scan point, structural parameters can be mapped throughout the cell or histological section [6], offering a 'diffraction contrast' by which one can localize also unstained biomolecular assemblies in cells and tissues, and at the same time investigate their structure. As an example, we address the sarcomeric organization in heart muscle cells (cardiomyocytes) [7,8], and show how the sarcomere organization evolves and differs between different cell types and maturation states. As a multi-scale approach, we then discuss sarcomeric structure in heart tissue sections, and then finally present phase contrast tomography reconstructions of an entire mouse heart.
[1] Bartels et al., Phys. Rev. Lett. (2015), 114, 048103
[2] Krenkel et al., Acta Crystallogr. A (2017), 73, 282-292
[3] Giewekemeyer et al., PNAS (2010), 107, 529-534
[4] Wilke et al., Optics Express (2012), 20, 19232-19254
[5] Nicolas et al., J. Synchrotron Rad. (2017), 24, 1163-1172
[6] Carboni & Nicolas et al., Biomed. Opt. Express (2017), 8, 4331–4347
[7] Bernhardt et al., New J. Phys. (2017), 19, 013012
[8] Nicolas et al., J. Appl. Crystallogr. (2017), 50, 612–620