I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[15320]
Open Access
Abstract: Determining the mechano-structural relations in biological materials with hierarchical structure is crucial to understanding natural optimization strategies and designing functional bioinspired composites. However, measuring the nanoscale mechanics and dynamic response is challenging when the specimen geometry and loading environment are physiologically complex. To overcome this challenge, we develop a combination of synchrotron X-ray diffraction testing and analytical modelling to explore the mechano-structural changes during bending loads on stomatopod cuticle. Stomatopod cuticle is an example of a hierarchical biomaterial optimized for high impact and bending resistance. Using models for large deformations of elastic continua, we measure cuticle strains from macroscopic deformations and combine diffraction-based fibril strains with stresses to quantify the local elastic moduli and nanoscale strain concentration factors, which are found to vary across cuticle sub-regions and under different flexion loading modes. This approach has the advantage of identifying constituent biomaterial properties and mechanisms in situ and is also suitable for studying time-dependent changes, such as concurrent strains of the nanofibrous phase that occur during physiological loading.
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Mar 2025
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Open Access
Abstract: Mimicking the fibrous structures of meat is a significant challenge as natural plant protein assemblies lack the fibrous organisation ubiquitous in mammalian muscle tissues. In this work, wet-spun hydrogel fibres resembling the anisotropic fibrous microstructure of meat are fabricated using carboxymethyl cellulose as a model polysaccharide and sodium caseinate as a model protein which are crosslinked using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Hydrogels and spun fibres were characterised using a combination of rheology (shear, oscillatory, and extensional), microscopy (light, polarised, and fluorescence), rheo-NMR, and X-ray diffraction. Examination of structuring behaviour under shear uncovered a relationship between enhanced biopolymer orientation along the fibre axis and a viscoelastic time-dependent ageing window for optimal hydrogel spinnability. This study provides novel rheological and structural insights into mechanisms of protein-polysaccharide assembly that may prove instrumental for development of tuneable fibres for applications in plant-based foods, tissue engineering, and biomaterials.
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Feb 2025
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I22-Small angle scattering & Diffraction
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Qian
Ma
,
Andri K.
Riau
,
Robert D.
Young
,
James S.
Bell
,
Olga
Shebanova
,
Nicholas J.
Terrill
,
Gary H. F.
Yam
,
Evelina
Han
,
Keith M.
Meek
,
Jodhbir S.
Mehta
,
Craig
Boote
Diamond Proposal Number(s):
[23514, 28285, 29862, 34903]
Open Access
Abstract: Purpose: Donor tissue shortfalls and postsurgical complications are driving novel corneal tissue regeneration approaches. Corneal stromal keratocytes (CSKs) have shown promise in promoting corneal repair and restoring transparency. We investigated the impact of intrastromal CSK injection on corneal ultrastructure and proteoglycan (PG) distribution in a rat injury model.
Methods: Rats were divided into four groups: normal (n = 12), injured (irregular phototherapeutic keratectomy centrally; n = 6), CSK (injured + human CSK intrastromal injection; n = 6), and PBS (injured + PBS injection; n = 6). Three weeks after treatment, corneas were examined by slit-lamp and optical coherence tomography. Corneal ultrastructure was analysed via small-angle x-ray scattering (collagen fibril diameter, interfibrillar spacing and matrix order), transmission electron microscopy with cuprolinic blue before and after chondroitinase digestion (CS/DS and KS PGs), and immunofluorescence staining (lumican and decorin).
Results: Irregular phototherapeutic keratectomy caused corneal opacity and significantly disrupted stromal ultrastructure, characterized by increased haze density (P < 0.0001), change in central corneal thickness (P = 0.0005), and interfibrillar spacing (P < 0.0001), along with decreased fibril diameter (P < 0.0001), matrix order (P < 0.0001), CS/DS (P < 0.0001) and KS (P < 0.0001) PGs, lumican, and decorin. CSK injection recovered corneal clarity and native stromal ultrastructure, with haze density (P = 0.8086), change in central corneal thickness (P = 0.9503), fibril diameter (P = 0.1139), interfibrillar spacing (P = 0.5879), matrix order (P = 0.9999), CS/DS (P = 0.9969) and KS (P = 0.2877) PGs, lumican, and decorin returning to normal. In contrast, the PBS group exhibited similar corneal injury responses to the injured group.
Conclusions: CSK injection resolved early stage corneal scarring by restoring stromal collagen arrangement and PG distribution, further endorsing its potential for treating corneal opacities.
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Feb 2025
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[33748, 35376]
Open Access
Abstract: We report that self-supporting mesoporous platinum 3D nanowires with a single diamond (SD) morphology and a high specific surface area of 40.4 m2 g–1 demonstrated enhanced stability toward the oxygen reduction reaction (ORR). These were found to be superior to commercially available carbon-supported Pt nanoparticles (Pt/C). After 1000 potential cycles, there was a 21% loss in surface area for SD-Pt, as compared with a 40.3% loss for Pt/C with no reduction in their half-wave potential (measured at J = 3.0 mA cm–2), whereas the Pt/C catalyst showed a 11.9 mV decrease. Our findings revealed that our SD-Pt thin films also exhibited excellent ORR activity, which offers significant potential for their application as high-performance cathode materials in alkaline fuel cells.
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Feb 2025
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[25602]
Open Access
Abstract: By developing a 3D X-ray modeling and spatially correlative imaging method for fibrous collagenous tissues, this study provides a comprehensive mapping of nanoscale deformation in the collagen fibril network across the intact bone-cartilage unit (BCU), whose healthy functioning is critical for joint function and preventing degeneration. Extracting the 3D fibril structure from 2D small-angle X-ray scattering before and during physiological compression reveals of dominant deformation modes, including crystallinity transitions, lateral fibril compression, and reorientation, which vary in a coupled, nonlinear, and correlated manner across the cartilage-bone interface. A distinct intermolecular arrangement of collagen molecules, and enhanced molecular-level disorder, is found in the cartilage (sliding) surface region. Just below, fibrils accommodate tissue strain by reorientation, which transitions molecular-level kinking or loss of crystallinity in the deep zone. Crystalline fibrils laterally shrink far more (20×) than they contract, possibly by water loss from between tropocollagen molecules. With the calcified plate acting as an anchor for surrounding tissue, a qualitative switch occurs in fibrillar deformation between the articular cartilage and calcified regions. These findings significantly advance this understanding of the complex, nonlinear ultrastructural dynamics at this critical interface, and opens avenues for developing targeted diagnostic and therapeutic strategies for musculoskeletal disorders.
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Nov 2024
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labSAXS-Offline SAXS and Sample Environment Development
I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[28661, 29137, 27721]
Open Access
Abstract: In situ small-angle X-ray scattering (SAXS) is a powerful technique for characterizing block-copolymer nano-object formation during polymerization-induced self-assembly. To work effectively in situ, it requires high intensity X-rays which enable the short acquisition times required for real-time measurements. However, routine access to synchrotron X-ray sources is expensive and highly competitive. Flow reactors provide an opportunity to obtain temporal resolution by operating at a consistent flow rate. Here, we equip a flow-reactor with an X-ray transparent flow-cell at the outlet which facilitates the use of a low-flux laboratory SAXS instrument for in situ monitoring. The formation and morphological evolution of spherical block copolymer nano-objects was characterized during reversible addition fragmentation chain transfer polymerization of diacetone acrylamide in the presence of a series of poly(dimethylacrylamide) (PDMAm) macromolecular chain transfer agents with varying degrees of polymerization. SAXS analysis indicated that during the polymerization, highly solvated, loosely defined aggregates form after approximately 100 s, followed by expulsion of solvent to form well-defined spherical particles with PDAAm cores and PDMAm stabilizer chains, which then grow as the polymerization proceeds. Analysis also indicates that the aggregation number (Nagg) increases during the reaction, likely due to collisions between swollen, growing nanoparticles. In situ SAXS conducted on PISA syntheses using different PDMAm DPs indicated a varying conformation of the chains in the particle cores, from collapsed chains for PDMAm47 to extended chains for PDMAm143. At high conversion, the final Nagg decreased as a function of increasing PDMAm DP, indicating increased steric stabilization afforded by the longer chains which is reflected by a decrease in both core diameter (from SAXS) and hydrodynamic diameter (from DLS) for a constant core DP of 400.
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Aug 2023
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I22-Small angle scattering & Diffraction
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Adelaide
Lerebours
,
Justyn
Regini
,
Roy A.
Quinlan
,
Toshihiro
Wada
,
Barbara
Pierscionek
,
Martin
Devonshire
,
Alexia A.
Kalligeraki
,
Alice
Uwineza
,
Laura
Young
,
John M.
Girkin
,
Phil
Warwick
,
Kurt
Smith
,
Masato
Hoshino
,
Kentaro
Uesugi
,
Naoto
Yagi
,
Nick
Terrill
,
Olga
Shebanova
,
Tim
Snow
,
Jim T.
Smith
Diamond Proposal Number(s):
[17075]
Open Access
Abstract: Recent studies apparently finding deleterious effects of radiation exposure on cataract formation in birds and voles living near Chernobyl represent a major challenge to current radiation protection regulations. This study conducted an integrated assessment of radiation exposure on cataractogenesis using the most advanced technologies available to assess the cataract status of lenses extracted from fish caught at both Chernobyl in Ukraine and Fukushima in Japan. It was hypothesised that these novel data would reveal positive correlations between radiation dose and early indicators of cataract formation.
The structure, function and optical properties of lenses were analysed from atomic to millimetre length scales. We measured the short-range order of the lens crystallin proteins using Small Angle X-Ray Scattering (SAXS) at both the SPring-8 and DIAMOND synchrotrons, the profile of the graded refractive index generated by these proteins, the epithelial cell density and organisation and finally the focal length of each lens.
The results showed no evidence of a difference between the focal length, the epithelial cell densities, the refractive indices, the interference functions and the short-range order of crystallin proteins (X-ray diffraction patterns) in lens from fish exposed to different radiation doses. It could be argued that animals in the natural environment which developed cataract would be more likely, for example, to suffer predation leading to survivor bias. But the cross-length scale study presented here, by evaluating small scale molecular and cellular changes in the lens (pre-cataract formation) significantly mitigates against this issue.
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Aug 2023
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B22-Multimode InfraRed imaging And Microspectroscopy
B23-Circular Dichroism
I07-Surface & interface diffraction
I16-Materials and Magnetism
I22-Small angle scattering & Diffraction
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N. J.
Terrill
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A.
Bombardi
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F.
Carla
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G.
Cinque
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M. J.
Derry
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A.
Milsom
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G.
Siligardi
,
T.
Snow
,
P. D.
Topham
,
X. B.
Zeng
,
T.
Zinn
Open Access
Abstract: Polymer and soft matter research have played an integral part in the development of Diamond Light Source ever since the facility took its first users in 2007. Early experiments explored highly swollen cubic lipid scaffolds using pressure to elicit phase transitions and liquid-crystal engineering . The facility now comprises 33 active synchrotron instruments, together with 13 electron microscopes, and other offline facilities. Diamond has an active polymer and soft matter science program exploring new phase space as well as many in operando studies. Later in the article, we will describe the opportunities available to this research community from the planned machine upgrade, which includes a higher-energy, lower divergence ring with better coherence.
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Jun 2023
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I22-Small angle scattering & Diffraction
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Richard
Stavri
,
Tabitha
Tay
,
Crispin C.
Wiles
,
Erica
Di Federico
,
Oliver
Boughton
,
Shaocheng
Ma
,
Angelo
Karunaratne
,
John H.
Churchwell
,
Rajarshi
Bhattacharya
,
Nicholas J.
Terrill
,
Justin P.
Cobb
,
Ulrich
Hansen
,
Richard L.
Abel
Diamond Proposal Number(s):
[17664, 13337]
Open Access
Abstract: Bone mechanics is well understood at every length scale except the nano-level. We aimed to investigate the relationship between bone nanoscale and tissue-level mechanics experimentally. We tested two hypotheses: (1) nanoscale strains were lower in hip fracture patients versus controls, and (2) nanoscale mineral and fibril strains were inversely correlated with aging and fracture. A cross-sectional sample of trabecular bone sections was prepared from the proximal femora of two human donor groups (aged 44–94 years): an aging non-fracture control group (n = 17) and a hip-fracture group (n = 20). Tissue, fibril, and mineral strain were measured simultaneously using synchrotron X-ray diffraction during tensile load to failure, then compared between groups using unpaired t-tests and correlated with age using Pearson’s correlation. Controls exhibited significantly greater peak tissue, mineral, and fibril strains than the hip fracture (all p < 0.05). Age was associated with a decrease in peak tissue (p = 0.099) and mineral (p = 0.004) strain, but not fibril strain (p = 0.260). Overall, hip fracture and aging were associated with changes in the nanoscale strain that are reflected at the tissue level. Data must be interpreted within the limitations of the observational cross-sectional study design, so we propose two new hypotheses on the importance of nanomechanics. (1) Hip fracture risk is increased by low tissue strain, which can be caused by low collagen or mineral strain. (2) Age-related loss of tissue strain is dependent on the loss of mineral but not fibril strain. Novel insights into bone nano- and tissue-level mechanics could provide a platform for the development of bone health diagnostics and interventions based on failure mechanisms from the nanoscale up.
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Jun 2023
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I22-Small angle scattering & Diffraction
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M.
Hassan Sk
,
S.
Agrawal
,
M.
Woolley
,
S. M.
Clarke
,
A.
Osundare
,
D.
Craske
,
Robert
Lindsay
,
Andrew J.
Smith
,
T.
Snow
,
T.
Zinn
,
N.
Terrill
Diamond Proposal Number(s):
[23699, 28693, 32669]
Open Access
Abstract: Here, we report the design and successful implementation of an ultra-low oxygen sample cell for use on the SAXS-WAXS (small-wide angle x-ray scattering) beamline I22 at DIAMOND. The rigorous exclusion of oxygen is found to require double jacketing with purge gas throughout the entire system, pipework, pumps, and the sample cell itself. This particularly includes a “double-window” arrangement at the sample location to accommodate the very tight geometrical restrictions of the sample position. The in situ cell design also requires the additional complexity of heating the sample/solution and real-time electrochemical measurements. We demonstrate the successful implementation of this arrangement with real-time in situ characterization of an iron foil corrosion evolving under the “sweet-scale environment,” very anoxic conditions common, in particular, commercial situations. The formation of iron carbonate, siderite, rather than iron oxide, indicates that our system is oxygen free down very low levels (<35 ppb at 80 °C).
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Apr 2023
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