I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[15444]
Abstract: Inorganic/organic hybrids have co-networks of inorganic and organic components, with the aim of obtaining synergy of the properties of those components. Here, a silica-gelatin sol-gel hybrid “ink” was directly 3D printed to produce 3D grid-like scaffolds, using a coupling agent, 3-glycidyloxypropyl)trimethoxysilane (GPTMS), to form covalent bonds between the silicate and gelatin co-networks. Scaffolds were printed with 1 mm strut separation, but the drying method affected the final architecture and properties. Freeze drying produced <40 μm struts and large ~700 μm channels. Critical point drying enabled strut consolidation and optimal mechanical properties, with ~160 μm struts and ~200 μm channels, which improved mechanical properties. This architecture was critical to cellular response: when chondrocytes were seeded on the scaffolds with 200 μm wide pore channels in vitro, collagen Type II matrix was preferentially produced (negligible amount of Type I or X were observed), indicative of hyaline-like cartilaginous matrix formation, but when pore channels were 700 μm wide, Type I collagen was prevalent. This was supported by Sox9 and Aggrecan expression. The scaffolds have potential for regeneration of articular cartilage regeneration, particularly in sports medicine cases.
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Feb 2021
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I11-High Resolution Powder Diffraction
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David C.
Green
,
Johannes
Ihli
,
Paul D.
Thornton
,
Mark A.
Holden
,
Bartosz
Marzec
,
Yi-Yeoun
Kim
,
Alex N.
Kulak
,
Mark A.
Levenstein
,
Chiu
Tang
,
Christophe
Lynch
,
Stephen E. D.
Webb
,
Christopher J.
Tynan
,
Fiona C.
Meldrum
Diamond Proposal Number(s):
[10137]
Open Access
Abstract: From biomineralization to synthesis, organic additives provide an effective means of controlling crystallization processes. There is growing evidence that these additives are often occluded within the crystal lattice. This promises an elegant means of creating nanocomposites and tuning physical properties. Here we use the incorporation of sulfonated fluorescent dyes to gain new understanding of additive occlusion in calcite (CaCO3), and to link morphological changes to occlusion mechanisms. We demonstrate that these additives are incorporated within specific zones, as defined by the growth conditions, and show how occlusion can govern changes in crystal shape. Fluorescence spectroscopy and lifetime imaging microscopy also show that the dyes experience unique local environments within different zones. Our strategy is then extended to simultaneously incorporate mixtures of dyes, whose fluorescence cascade creates calcite nanoparticles that fluoresce white. This offers a simple strategy for generating biocompatible and stable fluorescent nanoparticles whose output can be tuned as required.
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Nov 2016
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[15507]
Open Access
Abstract: Purpose:
To develop a biomimetic tumor tissue phantom which more closely reflects water diffusion in biological tissue than previously used phantoms, and to evaluate the stability of the phantom and its potential as a tool for validating diffusion-weighted (DW) MRI measurements.
Methods:
Coaxial-electrospraying was used to generate micron-sized hollow polymer spheres, which mimic cells. The bulk structure was immersed in water, providing a DW-MRI phantom whose apparent diffusion coefficient (ADC) and microstructural properties were evaluated over a period of 10 months. Independent characterization of the phantom's microstructure was performed using scanning electron microscopy (SEM). The repeatability of the construction process was investigated by generating a second phantom, which underwent high resolution synchrotron-CT as well as SEM and MR scans.
Results:
ADC values were stable (coefficients of variation (CoVs) < 5%), and varied with diffusion time, with average values of 1.44 ± 0.03 µm2/ms (Δ = 12 ms) and 1.20 ± 0.05 µm2/ms (Δ = 45 ms). Microstructural parameters showed greater variability (CoVs up to 13%), with evidence of bias in sphere size estimates. Similar trends were observed in the second phantom.
Conclusion:
A novel biomimetic phantom has been developed and shown to be stable over 10 months. It is envisaged that such phantoms will be used for further investigation of microstructural models relevant to characterizing tumor tissue, and may also find application in evaluating acquisition protocols and comparing DW-MRI-derived biomarkers obtained from different scanners at different sites.
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Nov 2017
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I08-Scanning X-ray Microscopy beamline (SXM)
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Diamond Proposal Number(s):
[17801, 17203]
Abstract: The good biocompatibility and corrosion resistance of the bulk CoCrMo alloy has resulted in it being used in the manufacture of implants and load bearing medical devices. These devices, however, can release wear and corrosion products which differ from the composition of the bulk CoCrMo alloy. The physicochemical characteristics of the particles and the associated in vivo reactivity are dictated by the wear mechanisms and electrochemical conditions at the sites of material loss. Debris released from CoCrMo hip bearings, taper junctions, or cement–stem interfaces can, therefore, have different chemical and morphological characteristics, which provide them with different in vivo toxicities. Here, we propose to assess and compare the characteristics of the particles released in vivo from CoCrMo tapers and cement–stem interfaces which have received less attention compared to debris originating from the hip bearings. The study uses state‐of‐art characterization techniques to provide a detailed understanding of the size, morphology, composition, and chemistry of the particles liberated from the wear and corrosion flakes from revised hip replacements, with an enzymatic treatment. The phase analyses identified Cr2O3 nanoparticles released from tapers and cement–stem interfaces, whose composition did not vary with origin or particle morphology. The size distributions showed significantly smaller particles were released from the stems, compared to the particles originating from the corresponding tapers. The investigation demonstrates that the tribocorrosive processes occurring at the taper and stem interfaces both result in Cr2O3 nanoparticle formation.
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Jun 2020
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[18388]
Abstract: The inefficiency of the chromium (III)-collagen cross-linking reaction during conventional leather processing results in severe environmental pollution from the waste chromium in the effluent. A mechanistic study using synchrotron-based small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) on ThruBlu tanned leather, revealed the effect of chromium sulphate and its pre-treatments on collagen structure and stability. By pre-treating with complexing agents such as sodium formate and disodium phthalate, as well as nanoclay (sodium montmorillonite), the uniformity through bovine hide collagen matrix were improved significantly. These pre-treatments effectively reduce the reactivity of chromium during its cross-linking reaction with collagen while retaining its bound water. However, collagen pre-treated with a covalent cross-linker (glutaraldehyde) results in a decrease in both chromium-collagen cross-linking and bound water while improving uniformity. These molecular-level insights can be developed into metrics to guide us towards a more sustainable future for the leather industry.
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Dec 2018
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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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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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B21-High Throughput SAXS
I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[17972, 16970]
Abstract: Catalytically active materials for the enhancement of personalized protective equipment (PPE) could be advantageous to help alleviate threats posed by neurotoxic organophosphorus compounds (OPs). Accordingly, a chimeric protein comprised of a supercharged green fluorescent protein (scGFP) and phosphotriesterase from Agrobacterium radiobacter (arPTE) was designed to drive the polymer surfactant (S–)-mediated self-assembly of microclusters to produce robust, enzymatically active materials. The chimera scGFP-arPTE was structurally characterized via circular dichroism spectroscopy and synchrotron radiation small-angle X-ray scattering, and its biophysical properties were determined. Significantly, the chimera exhibited greater thermal stability than the native constituent proteins, as well as a higher catalytic turnover number (kcat). Furthermore, scGFP-arPTE was electrostatically complexed with monomeric S–, driving self-assembly into [scGFP-arPTE][S–] nanoclusters, which could be dehydrated and cross-linked to yield enzymatically active [scGFP-arPTE][S–] porous films with a high-order structure. Moreover, these clusters could self-assemble within cotton fibers to generate active composite textiles without the need for the pretreatment of the fabrics. Significantly, the resulting materials maintained the biophysical activities of both constituent proteins and displayed recyclable and persistent activity against the nerve agent simulant paraoxon.
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Dec 2021
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I13-2-Diamond Manchester Imaging
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Diamond Proposal Number(s):
[12776]
Abstract: Many biological tissues have a complex hierarchical structure allowing them to function under demanding physiological loading conditions. Structural changes caused by ageing or disease can lead to loss of mechanical function. Therefore, it is necessary to characterise tissue structure to understand normal tissue function and the progression of disease. Ideally intact native tissues should be imaged in 3D and under physiological loading conditions. The current published in situ imaging methodologies demonstrate a compromise between imaging limitations and maintaining the samples native mechanical function. This review gives an overview of in situ imaging techniques used to visualise microstructural deformation of soft tissue, including three case studies of different tissues (tendon, intervertebral disc and artery). Some of the imaging techniques restricted analysis to observational mechanics or discrete strain measurement from invasive markers. Full‐field local surface strain measurement has been achieved using digital image correlation. Volumetric strain fields have successfully been quantified from in situ X‐ray microtomography (micro‐CT) studies of bone using digital volume correlation but not in soft tissue due to low X‐ray transmission contrast. With the latest developments in micro‐CT showing in‐line phase contrast capability to resolve native soft tissue microstructure, there is potential for future soft tissue mechanics research where 3D local strain can be quantified. These methods will provide information on the local 3D micromechanical environment experienced by cells in healthy, aged and diseased tissues. It is hoped that future applications of in situ imaging techniques will impact positively on the design and testing of potential tissue replacements or regenerative therapies.
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Apr 2018
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I11-High Resolution Powder Diffraction
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Abstract: The thermal transformation of aragonite to calcite in synthetic and biogenic aragonite (mussel nacre) is studied using Raman spectroscopy, high temperature synchrotron powder diffraction and scanning electron microscopy (SEM). Anomalous thermal behaviour in the form of plateau regions in the lattice parameter expansion of both the progenitor aragonite and transformed calcite phases is observed. This is attributed to the effect of increasing internal pressure caused by gas inclusions trapped within the structure during crystallisation. Biogenic aragonite exhibits a similar pattern of behaviour, except the plateau regions for each phase occupy a wider range of temperature which is likely due to the presence of intra-crystalline organic molecules intercalated in the atomic structure. An increase in micro-strain as a function of temperature is observed in the synthetic aragonite and calcite phases as the transformation progresses. This is attributed to the preservation of the original aragonite crystal morphology as the larger aragonite crystallites transform into smaller calcite crystals, with no intermediate phase being observed. For the biogenic sample this is not observed, and the effect of thermal treatment is to reduce the intrinsic strain through the degradation of the macromolecules forming the organic matrix of the nacre.
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Jan 2010
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