3D nanoscale analysis of bone healing around degrading Mg implants evaluated by X-ray scattering tensor tomography

AbstractThe nanostructural adaptation of bone is crucial for its compatibility with orthopedic implants. The bone’s nanostructure determines its mechanical properties, however little is known about its temporal and spatial adaptation in degrading implants. This study presents insights into this adaptation by applying electron microscopy, elemental analysis, and small-angle X-ray scattering tensor-tomography (SASTT). We extend the SASTT reconstruction to multiple radii of the reciprocal space vector q, providing a 3D reciprocal-space map per voxel. Each scattering curve is spatially linked to one voxel in the volume, and properties such as the thickness of the mineral particles are quantified. This reconstruction provides information on nanostructural adaptation during healing around a degrading ZX10 magnesium implant over the course of 18 months, using a sham as control. The nanostructural adaptation process is observed to start with an initially fast interfacial organization towards the implant direction, followed by a substantial reorganization of the volume around the implant, and an adaptation in the later degradation stages. The study sheds light on the complex bone-implant interaction in 3D, allowing a more guided approach towards the design of future implant materials, which are expected to be of great interest for further clinical studies on the bone-implant interaction.TOC text and figureDegrading Magnesium implants are mechanically and chemically well adapted orthopedic implant materials and ensure a gradual load transfer during bone healing due to their degradation. The impact of the implant degradation on the bone nanostructure is however not fully understood. This study unveils the processes 3D and shows different stages of bone healing.

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Fast acquisition protocol for X-ray scattering tensor tomography

Scientific Reports ◽

10.1038/s41598-021-02467-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jisoo Kim ◽

Matias Kagias ◽

Federica Marone ◽

Zhitian Shi ◽

Marco Stampanoni

Keyword(s):

Null Space ◽

Sufficient Information ◽

Single Shot ◽

Time Resolved ◽

X Ray ◽

Circular Pattern ◽

Rapid Acquisition ◽

Tensor Tomography ◽

X Ray Scattering ◽

Ray Scattering

AbstractMicrostructural information over an entire sample is important to understand the macroscopic behaviour of materials. X-ray scattering tensor tomography facilitates the investigation of the microstructural organisation in statistically large sample volumes. However, established acquisition protocols based on scanning small-angle X-ray scattering and X-ray grating interferometry inherently require long scan times even with highly brilliant X-ray sources. Recent developments in X-ray diffractive optics towards circular pattern arrays enable fast single-shot acquisition of the sample scattering properties with 2D omnidirectional sensitivity. X-ray scattering tensor tomography with the use of this circular grating array has been demonstrated. We propose here simple yet inherently rapid acquisition protocols for X-ray scattering tensor tomography leveraging on these new optical elements. Results from both simulation and experimental data, supported by a null space analysis, suggest that the proposed acquisition protocols are not only rapid but also corroborate that sufficient information for the accurate volumetric reconstruction of the scattering properties is provided. The proposed acquisition protocols will build the basis for rapid inspection and/or time-resolved tensor tomography of the microstructural organisation over an extended field of view.

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Fast Acquisition Protocol for X-ray Scattering Tensor Tomography

10.21203/rs.3.rs-599550/v1 ◽

2021 ◽

Author(s):

Jisoo Kim ◽

Matias Kagias ◽

Federica Marone ◽

Zhitian Shi ◽

Marco Stampanoni

Keyword(s):

Null Space ◽

Sufficient Information ◽

Single Shot ◽

Time Resolved ◽

X Ray ◽

Circular Pattern ◽

Rapid Acquisition ◽

Tensor Tomography ◽

X Ray Scattering ◽

Ray Scattering

Abstract Microstructural information over an entire sample is important to understand the macroscopic behavior of materials. X-ray scattering tensor tomography facilitates the investigation of the microstructural organisation in statistically large sample volumes. However, established acquisition protocols based on scanning small-angle X-ray scattering and X-ray grating interferometry inherently require long scan times even with highly brilliant X-ray sources. Recent developments in X-ray diffractive optics towards circular pattern arrays enable fast single-shot acquisition of the sample scattering properties with 2D omnidirectional sensitivity. Leveraging on these new optical elements, we propose here simple yet inherently rapid acquisition protocols forX-ray scattering tensor tomography. Results from both simulation and experimental data, supported by a null space analysis, suggest that the proposed acquisition protocols are not only rapid but also corroborate that sufficient information for the accurate volumetric reconstruction of the scattering properties is provided. The proposed acquisition protocols will build the basis for rapid inspection and/or time-resolved tensor tomography of the microstructural organisation over an extended field of view.

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Small-angle X-ray scattering tensor tomography: model of the three-dimensional reciprocal-space map, reconstruction algorithm and angular sampling requirements

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s205327331701614x ◽

2018 ◽

Vol 74 (1) ◽

pp. 12-24 ◽

Cited By ~ 13

Author(s):

Marianne Liebi ◽

Marios Georgiadis ◽

Joachim Kohlbrecher ◽

Mirko Holler ◽

Jörg Raabe ◽

...

Keyword(s):

Small Angle ◽

Three Dimensional ◽

Reconstruction Algorithm ◽

Reciprocal Space ◽

Mathematical Framework ◽

X Ray ◽

Tensor Tomography ◽

X Ray Scattering ◽

Degree Of Orientation ◽

Ray Scattering

Small-angle X-ray scattering tensor tomography, which allows reconstruction of the local three-dimensional reciprocal-space map within a three-dimensional sample as introduced by Liebiet al.[Nature(2015),527, 349–352], is described in more detail with regard to the mathematical framework and the optimization algorithm. For the case of trabecular bone samples from vertebrae it is shown that the model of the three-dimensional reciprocal-space map using spherical harmonics can adequately describe the measured data. The method enables the determination of nanostructure orientation and degree of orientation as demonstrated previously in a single momentum transferqrange. This article presents a reconstruction of the complete reciprocal-space map for the case of bone over extended ranges ofq. In addition, it is shown that uniform angular sampling and advanced regularization strategies help to reduce the amount of data required.

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Validation study of small-angle X-ray scattering tensor tomography

Journal of Synchrotron Radiation ◽

10.1107/s1600577520003860 ◽

2020 ◽

Vol 27 (3) ◽

pp. 779-787 ◽

Cited By ~ 1

Author(s):

Manuel Guizar-Sicairos ◽

Marios Georgiadis ◽

Marianne Liebi

Keyword(s):

Small Angle ◽

Structural Information ◽

Anisotropic Scattering ◽

Reciprocal Space ◽

Separate Analysis ◽

X Ray ◽

Tensor Tomography ◽

X Ray Scattering ◽

Dot Product ◽

Ray Scattering

Small-angle scattering tensor tomography (SASTT) is a recently developed technique able to tomographically reconstruct the 3D reciprocal space from voxels within a bulk volume. SASTT extends the concept of X-ray computed tomography, which typically reconstructs scalar values, by reconstructing a tensor per voxel, which represents the local nanostructure 3D organization. In this study, the nanostructure orientation in a human trabecular-bone sample obtained by SASTT was validated by sectioning the sample and using 3D scanning small-angle X-ray scattering (3D sSAXS) to measure and analyze the orientation from single voxels within each thin section. Besides the presence of cutting artefacts from the slicing process, the nanostructure orientations obtained with the two independent methods were in good agreement, as quantified with the absolute value of the dot product calculated between the nanostructure main orientations obtained in each voxel. The average dot product per voxel over the full sample containing over 10 000 voxels was 0.84, and in six slices, in which fewer cutting artefacts were observed, the dot product increased to 0.91. In addition, SAXS tensor tomography not only yields orientation information but can also reconstruct the full 3D reciprocal-space map. It is shown that the measured anisotropic scattering for individual voxels was reproduced from the SASTT reconstruction in each voxel of the 3D sample. The scattering curves along different 3D directions are validated with data from single voxels, demonstrating SASTT's potential for a separate analysis of nanostructure orientation and structural information from the angle-dependent intensity distribution.

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X-ray scattering tensor tomography with circular gratings

Applied Physics Letters ◽

10.1063/1.5145361 ◽

2020 ◽

Vol 116 (13) ◽

pp. 134102

Author(s):

Jisoo Kim ◽

Matias Kagias ◽

Federica Marone ◽

Marco Stampanoni

Keyword(s):

X Ray ◽

Tensor Tomography ◽

X Ray Scattering ◽

Ray Scattering

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Nanostructural Analysis of Human Dentine using 3D Small Angle X-ray Scattering Tensor Tomography

10.22443/rms.mmc2021.281 ◽

2021 ◽

Author(s):

Tayyaba Rabnawaz

Keyword(s):

Small Angle ◽

X Ray ◽

Tensor Tomography ◽

X Ray Scattering ◽

Human Dentine ◽

Ray Scattering

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Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077402 ◽

1983 ◽

Vol 41 ◽

pp. 766-767

Author(s):

Eva-Maria Mandelkow ◽

Eckhard Mandelkow ◽

Joan Bordas

Keyword(s):

Electron Microscopy ◽

Dynamic Equilibrium ◽

Time Resolved ◽

X Ray ◽

Additional Information ◽

X Ray Scattering ◽

Low Concentrations ◽

Microtubule Growth ◽

Ray Patterns ◽

Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

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Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181269 ◽

1990 ◽

Vol 48 (1) ◽

pp. 502-503

Author(s):

Eva-Maria Mandelkow ◽

Ron Milligan

Keyword(s):

Electron Microscopy ◽

Dynamic Instability ◽

Entire Solution ◽

Reaction Scheme ◽

Time Resolved ◽

X Ray ◽

X Ray Scattering ◽

A Chain ◽

Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

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