I20-Scanning-X-ray spectroscopy (XAS/XES)
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Diamond Proposal Number(s):
[25495]
Abstract: Magnetite nanoparticles possess numerous fundamental, biomedical, and industrial applications, many of which depend on tuning the magnetic properties. This is often achieved by the incorporation of trace and minor elements into the magnetite lattice. Such incorporation was shown to depend strongly on the magnetite formation pathway (i.e., abiotic vs biological), but the mechanisms controlling element partitioning between magnetite and its surrounding precipitation solution remain to be elucidated. Here, we used a combination of theoretical modeling (lattice and crystal field theories) and experimental evidence (high-resolution inductively coupled plasma–mass spectrometry and X-ray absorption spectroscopy) to demonstrate that element incorporation into abiotic magnetite nanoparticles is controlled principally by cation size and valence. Elements from the first series of transition metals (Cr to Zn) constituted exceptions to this finding, as their incorporation appeared to be also controlled by the energy levels of their unfilled 3d orbitals, in line with crystal field mechanisms. We finally show that element incorporation into biological magnetite nanoparticles produced by magnetotactic bacteria (MTB) cannot be explained by crystal–chemical parameters alone, which points to the biological control exerted by the bacteria over the element transfer between the MTB growth medium and the intracellular environment. This screening effect generates biological magnetite with a purer chemical composition in comparison to the abiotic materials formed in a solution of similar composition. Our work establishes a theoretical framework for understanding the crystal–chemical and biological controls of trace and minor cation incorporation into magnetite, thereby providing predictive methods to tailor the composition of magnetite nanoparticles for improved control over magnetic properties.
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Jan 2023
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I12-JEEP: Joint Engineering, Environmental and Processing
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Diamond Proposal Number(s):
[28087, 26608]
Abstract: Ti40Zr10Cu32Pd14Ga4 and Ti40Zr10Cu32Pd14Sn4 (in at.%) bulk metallic glasses (BMGs) with different geometries (wedges, rods, ribbons and discs) were prepared by suction casting, melt spinning and splat quenching, respectively. For comparison, the reference Ti40Zr10Cu36Pd14 BMG was cast as a rod with 2 mm diameter and in wedge-shaped form. High-energy X-ray diffraction measurements yielded a critical casting thickness of 2.4, 2.1 and at least 4 mm for the reference, Ga-containing, and Sn-containing BMGs, respectively. The extension of the supercooled liquid region of about 50 K, measured for the glassy rods and ribbons by differential scanning calorimetry, is larger than that of only 20 K found for the splat-quenched discs. As to the alloys’ mechanical properties, the Ti40Zr10Cu36Pd14 glassy rods deform plastically in compression up to a strain of 3.8% and possess a Young’s modulus of 78 GPa. The Sn- and Ga- containing BMG rods reach respectively a plastic strain of 6.1% and 4.7%, and a Young’s modulus of 72 and 63 GPa. Corrosion tests were performed by electrochemical experiments, and the highest pitting resistance was observed for Ti40Zr10Cu32Pd14Sn4 (pitting overpotential ηpit = 446 mV) compared to Ti40Zr10Cu32Pd14Ga4 (379 mV) and Ti40Zr10Cu36Pd14 (183 mV). The results of live/dead assay and cell viability revealed excellent biocompatibility for the Ga-containing BMGs.
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Jan 2023
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B21-High Throughput SAXS
I22-Small angle scattering & Diffraction
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Tamara
Ehm
,
Hila
Shinar
,
Guy
Jacoby
,
Sagi
Meir
,
Gil
Koren
,
Merav
Segal Asher
,
Joanna
Korpanty
,
Matthew P.
Thompson
,
Nathan C.
Gianneschi
,
Michael M.
Kozlov
,
Salome
Azoulay-Ginsburg
,
Roey J.
Amir
,
Joachim O.
Rädler
,
Roy
Beck
Diamond Proposal Number(s):
[21971, 24693, 29428, 28723, 28010]
Open Access
Abstract: Intrinsically disordered peptide amphiphiles (IDPAs) present a novel class of synthetic conjugates that consist of short hydrophilic polypeptides anchored to hydrocarbon chains. These hybrid polymer-lipid block constructs spontaneously self-assemble into dispersed nanoscopic aggregates or ordered mesophases in aqueous solution due to hydrophobic interactions. Yet, the possible sequence variations and their influence on the self-assembly structures are vast and have hardly been explored. Here, we measure the nanoscopic self-assembled structures of four IDPA systems that differ by their amino acid sequence. We show that permutations in the charge pattern along the sequence remarkably alter the headgroup conformation and consequently alter the pH-triggered phase transitions between spherical, cylindrical micelles and hexagonal condensed phases. We demonstrate that even a single amino acid mutation is sufficient to tune structural transitions in the condensed IDPA mesophases, while peptide conformations remain unfolded and disordered. Furthermore, alteration of the peptide sequence can render IDPAs to become susceptible to enzymatic cleavage and induce enzymatically activated phase transitions. These results hold great potential for embedding multiple functionalities into lipid nanoparticle delivery systems by incorporating IDPAs with the desired properties.
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Dec 2022
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Zhiyuan
Ding
,
Si
Gao
,
Weina
Fang
,
Chen
Huang
,
Liqi
Zhou
,
Xudong
Pei
,
Xiaoguo
Liu
,
Xiaoqing
Pan
,
Chunhai
Fan
,
Angus I.
Kirkland
,
Peng
Wang
Open Access
Abstract: Three dimensional scaffolded DNA origami with inorganic nanoparticles has been used to create tailored multidimensional nanostructures. However, the image contrast of DNA is poorer than those of the heavy nanoparticles in conventional transmission electron microscopy at high defocus so that the biological and non-biological components in 3D scaffolds cannot be simultaneously resolved using tomography of samples in a native state. We demonstrate the use of electron ptychography to recover high contrast phase information from all components in a DNA origami scaffold without staining. We further quantitatively evaluate the enhancement of contrast in comparison with conventional transmission electron microscopy. In addition, We show that for ptychography post-reconstruction focusing simplifies the workflow and reduces electron dose and beam damage.
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Aug 2022
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[25197]
Open Access
Abstract: Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability, crosslinkers are used in excess, with stability guided by indicators including the hydrothermal denaturation temperature, the enzymatic resistance and the degree of crosslinking. Yet, understanding of the intermolecular structure in collagen fibrils which imparts the intrinsic stability of the ABPs is lacking, and the discrepancies in the stability criteria in varied conditions are poorly explained. In this study, synchrotron small-angle X-ray scattering (SAXS) in combination with thermal and colorimetric methods are employed to investigate the changes in the structure and the stability of ABPs during crosslinking using glutaraldehyde (GA) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) at different concentrations. Based on the findings, a mechanism is proposed to explicate the crosslinking effects on collagen structure and the relationship between the structure and each stability indicator. At low crosslinker concentrations, the telopeptidyl-helical linkages are preferred which cause rearrangements in the intermolecular structure of collagen, and efficiently contribute to its stabilities. Excess crosslinking is revealed by a revert trend in structural changes and the plateauing of the stabilities, assigning to the helical-helical linkages and monovalent bindings. The former would improve thermal stability but not collagenase resistance, whereas the latter have negligible effects. Overall, this study provides mechanistic understanding of the chemical crosslinking of ABPs which will contribute to the future development of more efficient and economically viable strategies to produce bioprostheses.
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Aug 2022
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B18-Core EXAFS
I14-Hard X-ray Nanoprobe
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Abstract: This thesis work proposes two main objectives: 1) developing conjugated hybrids protein-nanomaterial, employing the photoluminescence and metallic character from nanostructures such as nanoparticles and metal nanocluster; 2) design hybrids based on engineered CTPR modified with metal-coordinating residues for tailored applications in sensing, imaging and bioelectronics. In order to achieve these two objectives, this thesis work is divided in 5 chapters in which different uses for hybrid CTPR protein-nanomaterials are explored.
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Jun 2022
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I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[19081]
Open Access
Abstract: The protective carapace of Skogsbergia lerneri, a marine ostracod, is scratch-resistant and transparent. The compositional and structural organisation of the carapace that underlies these properties is unknown. In this study, we aimed to quantify and determine the distribution of chemical elements and chitin within the carapace of adult ostracods, as well as at different stages of ostracod development, to gain insight into its composition. Elemental analyses included X-ray absorption near-edge structure, X-ray fluorescence and X-ray diffraction. Nonlinear microscopy and spectral imaging were performed to determine chitin distribution within the carapace. High levels of calcium (20.3%) and substantial levels of magnesium (1.89%) were identified throughout development. Amorphous calcium carbonate (ACC) was detected in carapaces of all developmental stages, with the polymorph, aragonite, identified in A-1 and adult carapaces. Novel chitin-derived second harmonic generation signals (430/5 nm) were detected. Quantification of relative chitin content within the developing and adult carapaces identified negligible differences in chitin content between developmental stages and adult carapaces, except for the lower chitin contribution in A-2 (66.8 ± 7.6%) compared to A-5 (85.5 ± 10%) (p = 0.03). Skogsbergia lerneri carapace calcium carbonate composition was distinct to other myodocopid ostracods. These calcium polymorphs and ACC are described in other biological transparent materials, and with the consistent chitin distribution throughout S. lerneri development, may imply a biological adaptation to preserve carapace physical properties. Realisation of S. lerneri carapace synthesis and structural organisation will enable exploitation to manufacture biomaterials and biomimetics with huge potential in industrial and military applications.
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Jun 2022
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I13-2-Diamond Manchester Imaging
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Nicole
Sommer
,
Daniela
Hirzberger
,
Lisa
Paar
,
Leopold
Berger
,
Hanna
Cwieka
,
Uwe Y.
Schwarze
,
Valentin
Herber
,
Begum
Okutan
,
Andrew J.
Bodey
,
Regine
Willumeit-Römer
,
Berit
Zeller-Plumhoff
,
Jörg F.
Löffler
,
Annelie M.
Weinberg
Diamond Proposal Number(s):
[25485]
Abstract: Implant removal is unnecessary for biodegradable magnesium (Mg)-based implants and, therefore, the related risk for implant-induced fractures is limited. Aging, on the other hand, is associated with low bone-turnover and decreased bone mass and density, and thus increased fracture risk. Osteoporosis is accompanied by Mg deficiency, therefore, we hypothesized that Mg-based implants may support bone formation by Mg2+ ion release in an ovariectomy-induced osteoporotic rat model. Hence, we investigated osseointegration and implant degradation of a low-alloyed, degrading Mg–Zn–Ca implant (ZX00) in ovariectomy-induced osteoporotic (Osteo), old healthy (OH), and juvenile healthy (JH) groups of female Sprague Dawley rats via in vivo micro-computed tomography (µCT). For the Osteo rats, we demonstrate diminished trabecular bone already after 8 weeks upon ovariectomy and significantly enhanced implant volume loss, with correspondingly pronounced gas formation, compared to the OH and JH groups. Sclerotic rim development was observed in about half of the osteoporotic rats, suggesting a prevention from foreign-body and osteonecrosis development. Synchrotron radiation-based µCT confirmed lower bone volume fractions in the Osteo group compared to the OH and JH groups. Qualitative histological analysis additionally visualized the enhanced implant degradation in the Osteo group. To date, ZX00 provides an interesting implant material for young and older healthy patients, but it may not be of advantage in pharmacologically untreated osteoporotic conditions.
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May 2022
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[10315, 16497, 22575]
Open Access
Abstract: Musculoskeletal tissues are complex hierarchical materials where mechanical response is linked to structural and material properties at different dimensional levels. Therefore, high-resolution three-dimensional tomography is very useful for assessing tissue properties at different scales. In particular, Synchrotron Radiation micro-Computed Tomography (SR-microCT) has been used in several applications to analyze the structure of bone and biomaterials. In the past decade the development of digital volume correlation (DVC) algorithms applied to SR-microCT images and its combination with in situ mechanical testing (four-dimensional imaging) have allowed researchers to visualise, for the first time, the deformation of bone tissue and its interaction with biomaterials under different loading scenarios. However, there are several experimental challenges that make these measurements difficult and at high risk of failure. Challenges relate to sample preparation, imaging parameters, loading setup, accumulated tissue damage for multiple tomographic acquisitions, reconstruction methods and data processing. Considering that access to SR-microCT facilities is usually associated with bidding processes and long waiting times, the failure of these experiments could notably slow down the advancement of this research area and reduce its impact. Many of the experimental failures can be avoided with increased experience in performing the tests and better guidelines for preparation and execution of these complex experiments; publication of negative results could help interested researchers to avoid recurring mistakes. Therefore, the goal of this article is to highlight the potential and pitfalls in the design and execution of in situ SR-microCT experiments, involving multiple scans, of musculoskeletal tissues for the assessment of their structural and/or mechanical properties. The advice and guidelines that follow should improve the success rate of this type of experiment, allowing the community to reach higher impact more efficiently.
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May 2022
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I18-Microfocus Spectroscopy
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Sarah
Gosling
,
Doriana
Calabrese
,
Jayakrupakar
Nallala
,
Charlene
Greenwood
,
Sarah
Pinder
,
Lorraine
King
,
Jeffrey
Marks
,
Donna
Pinto
,
Thomas
Lynch
,
Iain D.
Lyburn
,
E. Shelley
Hwang
,
Cruk
Grand Challenge Precision Consortium
,
Keith
Rogers
,
Nicholas
Stone
Diamond Proposal Number(s):
[21565, 25414, 27300]
Open Access
Abstract: Ductal carcinoma in situ (DCIS) is frequently associated with breast calcification. This study combines
multiple analytical techniques to investigate the heterogeneity of these calcifications at the micrometre
scale. X-ray diffraction, scanning electron microscopy and Raman and Fourier-transform infrared spectroscopy were used to determine the physicochemical and crystallographic properties of type II breast calcifications located in formalin fixed paraffin embedded DCIS breast tissue samples. Multiple calcium phosphate phases were identified across the calcifications, distributed in different patterns. Hydroxyapatite was
the dominant mineral, with magnesium whitlockite found at the calcification edge. Amorphous calcium
phosphate and octacalcium phosphate were also identified close to the calcification edge at the apparent
mineral/matrix barrier. Crystallographic features of hydroxyapatite also varied across the calcifications, with
higher crystallinity centrally, and highest carbonate substitution at the calcification edge. Protein was also
differentially distributed across the calcification and the surrounding soft tissue, with collagen and β-pleated
protein features present to differing extents. Combination of analytical techniques in this study was essential
to understand the heterogeneity of breast calcifications and how this may link crystallographic and physicochemical properties of calcifications to the surrounding tissue microenvironment.
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Mar 2022
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