I13-2-Diamond Manchester Imaging
I14-Hard X-ray Nanoprobe
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Kamila
Iskhakova
,
Hanna
Cwieka
,
Svenja
Meers
,
Heike
Helmholz
,
Anton
Davydok
,
Malte
Storm
,
Ivo Matteo
Baltruschat
,
Silvia
Galli
,
Daniel
Pröfrock
,
Olga
Will
,
Mirko
Gerle
,
Timo
Damm
,
Sandra
Sefa
,
Weilue
He
,
Keith
Macrenaris
,
Malte
Soujon
,
Felix
Beckmann
,
Julian
Moosmann
,
Thomas
O'Hallaran
,
Roger J.
Guillory
,
D. C. Florian
Wieland
,
Berit
Zeller-Plumhoff
,
Regine
Willumeit-Römer
Diamond Proposal Number(s):
[25078]
Open Access
Abstract: Magnesium (Mg) – based alloys are becoming attractive materials for medical applications as temporary bone implants for support of fracture healing, e.g. as a suture anchor. Due to their mechanical properties and biocompatibility, they may replace titanium or stainless-steel implants, commonly used in orthopedic field. Nevertheless, patient safety has to be assured by finding a long-term balance between metal degradation, osseointegration, bone ultrastructure adaptation and element distribution in organs. In order to determine the implant behavior and its influence on bone and tissues, we investigated two Mg alloys with gadolinium contents of 5 and 10 wt percent in comparison to permanent materials titanium and polyether ether ketone. The implants were present in rat tibia for 10, 20 and 32 weeks before sacrifice of the animal. Synchrotron radiation-based micro computed tomography enables the distinction of features like residual metal, degradation layer and bone structure. Additionally, X-ray diffraction and X-ray fluorescence yield information on parameters describing the bone ultrastructure and elemental composition at the bone-to-implant interface. Finally, with element specific mass spectrometry, the elements and their accumulation in the main organs and tissues are traced. The results show that Mg-xGd implants degrade in vivo under the formation of a stable degradation layer with bone remodeling similar to that of Ti after 10 weeks. No accumulation of Mg and Gd was observed in selected organs, except for the interfacial bone after 8 months of healing. Thus, we confirm that Mg-5Gd and Mg-10Gd are suitable material choices for bone implants.
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Nov 2024
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I13-2-Diamond Manchester Imaging
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Nicholas T. H.
Farr
,
David A.
Gregory
,
Victoria L.
Workman
,
Cassandra
Rauert
,
Sabiniano
Roman
,
Alexander J.
Knight
,
Anthony J.
Bullock
,
Alexander I.
Tartakovskii
,
Kevin V.
Thomas
,
Christopher R.
Chapple
,
Jan
Deprest
,
Sheila
Macneil
,
Cornelia
Rodenburg
Diamond Proposal Number(s):
[33034]
Open Access
Abstract: The failure of polypropylene mesh is marked by significant side effects and debilitation, arising from a complex interplay of factors. One key contributor is the pronounced physico-mechanical mismatch between the polypropylene (PP) fibres and surrounding tissues, resulting in substantial physical damage, inflammation, and persistent pain. However, the primary cause of sustained inflammation due to polypropylene itself remains incompletely understood. This study comprises a comprehensive, multi-pronged investigation to unravel the effects of implantation on a presumed inert PP mesh in sheep. Employing both advanced and conventional techniques to discern the physical and chemical transformations of the implanted PP. Our analyses reveal a surface degradation and oxidation of polypropylene fibres after 60 days implantation, persisting and intensifying at the 180-day mark. The emergence and accumulation of PP debris in the tissue surrounding the implant also increased with implantation time. We demonstrate observable physical and mechanical alterations in the fibre surface and stiffness. Our study shows surface alterations which indicate that PP is evidently less chemically inert than was initially presumed. These findings underscore the need for a re-evaluation of the biocompatibility and long-term consequences of using PP mesh implants.
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Sep 2024
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I22-Small angle scattering & Diffraction
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Heithem
Ben Amara
,
Diana C.
Martinez
,
Kamila
Iskhakova
,
Lena
Emanuelsson
,
Birgitta
Norlindh
,
Anna
Johansson Loo
,
D. C. Florian
Wieland
,
Berit
Zeller-Plumhoff
,
Regine
Willumeit-Römer
,
Tomasz
Plocinski
,
Wojciech
Swieszkowski
,
Furqan A.
Shah
,
Anders
Palmquist
,
Omar
Omar
,
Peter
Thomsen
Open Access
Abstract: Orthopedic implants made of biodegradable magnesium (Mg) provide an alternative to nondegradable implants for fracture repair. Widely reported to be pro-osteogenic, Mg implants are also believed to be anti-inflammatory and anti-osteoclastic, but this is difficult to reconcile with the early clinical inflammation observed around these implants. Here, by surveying implant healing in a rat bone model, we determined the cellular responses and structural assembly of bone correlated with the surface changes of Mg implants inherent in degradation. We show that, compared to titanium, both high-purity (99.998%) and clinical-grade, rare earth-alloyed (MgYREZr) Mg implants create an initial, transient proinflammatory environment that facilitates inducible nitric oxide synthase-mediated macrophage polarization, osteoclastogenesis, and neoangiogenesis programs. While this immunomodulation subsequently reinforces reparative osteogenesis at the surface of both Mg implants, the faster degradation of high-purity Mg implants, but not MgYREZr implants, elicits a compositional alteration in the interfacial bone and a previously unknown proadipogenic response with persistent low-grade inflammation in the surrounding bone marrow. Beyond the need for rigorous tailoring of Mg implants, these data highlight the need to closely monitor osseointegration not only at the immediate implant surface but also in the peri-implant bone and adjacent bone marrow.
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Aug 2024
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[21476, 27911]
Open Access
Abstract: Hierarchical porous phosphate-based glasses (PPG) have great potential in biomedicine. Micropores (pore size < 2 nm) increase the surface area, mesopores (pore size 2 to 50 nm) facilitate the absorption and diffusion of therapeutic ions and molecules making them ideal controlled delivery systems, while macropores (pore size > 50 nm) facilitate the movement and diffusion of cells and fluids. In addition, the bioresorbability of PPG allows for their complete solubility in body fluid, alongside simultaneous formation of new tissue. Making PPG via the traditional melt-quenching (MQ) synthesis method used for phosphate-based glasses (PG), is not straightforward. Hence, we present here a route for preparing such glasses using a combination of sol-gel (SG) and templating methods. Hierarchical porous PPG in the P2O5-CaO-Na2O system with the addition of 1, 3 and 5 mol % of Zn2+ were prepared with pore dimensions ranging from the micro- to the macro scales using Pluronic 123 (P123) as a surfactant. The presence of micropores (0.30-0.46 nm), mesopores (1.75 to 9.35 nm) and macropores (163-207 nm) was assessed via synchrotron-based Small-Angle X-ray Scattering (SAXS), with the presence of the latter two confirmed by Scanning Electron Microscopy (SEM). Structural characterisation performed using 31P solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and Fourier Transform Infra-red (FT-IR) spectroscopies shows the presence of Q2, Q1 and Q0 phosphate species with a predominance of Q1 species in all compositions. Dissolution studies in deionised (DI) water confirm that controlled release of phosphates, Ca2+, Na+ and Zn2+ is achieved over a period of 7 days. In particular, the release of Zn2+ is proportional to its loading, making its delivery particularly easy to control.
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Jul 2024
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I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[30196]
Open Access
Abstract: Heterotopic ossification (HO) in tendons can lead to increased pain and poor tendon function. Although it is believed to share some characteristics with bone, the structural and elemental compositions of HO deposits have not been fully elucidated. This study utilizes a multimodal and multiscale approach for structural and elemental characterization of HO deposits in healing rat Achilles tendons at 3, 6, 12, 16, and 20 weeks post transection. The microscale tomography and scanning electron microscopy results indicate increased mineral density and Ca/P ratio in the maturing HO deposits (12 and 20 weeks), when compared to the early time points (3 weeks). Visually, the mature HO deposits present microstructures similar to calcaneal bone. Through synchrotron-based X-ray scattering and fluorescence, the hydroxyapatite (HA) crystallites are shorter along the c-axis and become larger in the ab-plane with increasing healing time, while the HA crystal thickness remains within the reference values for bone. At the mineralization boundary, the overlap between high levels of calcium and prominent crystallite formation was outlined by the presence of zinc and iron. In the mature HO deposits, the calcium content was highest, and zinc was more present internally, which could be indicative of HO deposit remodeling. This study emphasizes the structural and elemental similarities between the calcaneal bone and HO deposits.
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Jul 2024
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I22-Small angle scattering & Diffraction
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Kamila
Iskhakova
,
D. C. Florian
Wieland
,
Romy
Marek
,
Uwe Y.
Schwarze
,
Anton
Davydok
,
Hanna
Cwieka
,
Tamadur
Albaraghtheh
,
Jan
Reimers
,
Birte
Hindenlang
,
Sandra
Sefa
,
André
Lopes Marinho
,
Regine
Willumeit-Römer
,
Berit
Zeller-Plumhoff
Diamond Proposal Number(s):
[28881]
Open Access
Abstract: Magnesium alloys are some of the most convenient biodegradable materials for bone fracture treatment due to their tailorable degradation rate, biocompatibility, and mechanical properties resembling those of bone. Despite the fact that magnesium-based implants and ZX00 (Mg-0.45Zn-0.45Ca in wt.%), in particular, have been shown to have suitable degradation rates and good osseointegration, knowledge gaps remain in our understanding of the impact of their degradation properties on the bone’s ultrastructure. Bone is a hierarchically structured material, where not only the microstructure but also the ultrastructure are important as properties like the local mechanical response are determined by it. This study presents the first comparative analysis of bone ultrastructure parameters with high spatial resolution around ZX00 and Ti implants after 6, 12, and 24 weeks of healing. The mineralization was investigated, revealing a significant decrease in the lattice spacing of the (002) Bragg’s peak closer to the ZX00 implant in comparison to Ti, while no significant difference in the crystallite size was observed. The hydroxyapatite platelet thickness and osteon density demonstrated a decrease closer to the ZX00 implant interface. Correlative indentation and strain maps obtained by scanning X-ray diffraction measurements revealed a higher stiffness and faster mechanical adaptation of the bone surrounding Ti implants as compared to the ZX00 ones. Thus, the results suggest the incorporation of Mg2+ ions into the bone ultrastructure, as well as a lower degree of remodeling and stiffness of the bone in the presence of ZX00 implants than Ti.
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Jul 2024
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[26698]
Abstract: Hydrogels (HGs) with enhanced structural and mechanical properties can be generated by combining two or more different building blocks in the same matrix. It has been widely demonstrated that the addition of peptides, proteins, sugars, or polymers to the low molecular weight hydrogelator Fmoc-FF [(fluorenyl methyloxycarbonyl)-diphenylalanine] can significantly modify the chemical and structural features of the resulting HGs. In this context, the formulation of multicomponent HGs has been previously described, in which Fmoc-FF is mixed with telechelic diacrylate α-/ω-substituted polyethylene-glycol derivatives (PEGDAs) with a molecular weight of 575 (PEGDA1) or 250 Da (PEGDA2). Here, we investigate the possibility to generate Fmoc-FF-based interpenetrated networks performing the cross-link reaction of PEGDA monomers in supramolecular peptide hydrogels. This approach can allow the modulation of the final properties of the material, in terms of water behavior, topography, and rigidity. The results indicate that the polymerization time, the polymer length, and the Fmoc-FF/PEGDA ratio play a crucial role in the chemistry of the materials and, consequently, of their potential application.
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Jun 2024
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VMXi-Versatile Macromolecular Crystallography in situ
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Keke
Zheng
,
Jingxiao
Zhong
,
Jingrui
Hu
,
Eve
Nebbiolo
,
Juan
Sanchez-Weatherby
,
Tengteng
Tang
,
William J.
Landis
,
Junning
Chen
,
Peter
Winlove
,
Benjamin E.
Sherlock
,
James
Bell
Diamond Proposal Number(s):
[27314]
Open Access
Abstract: The process of mineralization fundamentally alters collagenous tissue biomechanics. While the structure and organization of mineral particles have been widely studied, the impact of mineralization on collagen matrix structure, particularly at the molecular scale, requires further investigation. In this study, synchrotron X-ray scattering (XRD) and polarization-resolved second harmonic generation microscopy (pSHG) were used to study normally mineralizing turkey leg tendon in tissue zones representing different stages of mineralization. XRD data demonstrated statistically significant differences in collagen D-period, intermolecular spacing, fibril and molecular dispersion and relative supramolecular twists between non-mineralizing, early mineralizing and late mineralizing zones. pSHG analysis of the same tendon zones showed the degree of collagen fibril organization was significantly greater in early and late mineralizing zones compared to non-mineralizing zones. The combination of XRD and pSHG data provide new insights into hierarchical collagen–mineral interactions, notably concerning possible cleavage of intra- or interfibrillar bonds, occlusion and reorganization of collagen by mineral with time. The complementary application of XRD and fast, label-free and non-destructive pSHG optical measurements presents a pathway for future investigations into the dynamics of molecular scale changes in collagen in the presence of increasing mineral deposition.
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Jun 2024
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[27895]
Open Access
Abstract: Peptide-based supramolecular hydrogels are an attractive class of soft materials for biomedical applications when biocompatibility is a key requirement as they exploit the physical self-assembly of short self-assembling peptides avoiding the need for chemical cross-linking. Based on the knowledge developed through our previous work, we designed two novel peptides, E(FKFE)2 and K(FEFK)2, that form transparent hydrogels at pH 7. We characterized the phase behavior of these peptides and showed the clear link that exists between the charge carried by the peptides and the physical state of the samples. We subsequently demonstrate the cytocompatibility of the hydrogel and its suitability for 3D cell culture using 3T3 fibroblasts and human mesenchymal stem cells. We then loaded the hydrogels with two polymers, poly-l-lysine and dextran. When polymer and peptide fibers carry opposite charges, the size of the elemental fibril formed decreases, while the overall level of fiber aggregation and fiber bundle formation increases. This overall network topology change, and increase in cross-link stability and density, leads to an overall increase in the hydrogel mechanical properties and stability, i.e., resistance to swelling when placed in excess media. Finally, we investigate the diffusion of the polymers out of the hydrogels and show how electrostatic interactions can be used to control the release of large molecules. The work clearly shows how polymers can be used to tailor the properties of peptide hydrogels through guided intermolecular interactions and demonstrates the potential of these new soft hydrogels for use in the biomedical field in particular for delivery or large molecular payloads and cells as well as scaffolds for 3D cell culture.
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May 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Open Access
Abstract: Infection is the leading cause of biomedical implant failure, making the incorporation of antibacterial elements highly desirable. However, new alloys must also possess a low elastic modulus, to prevent stress shielding and bone resorption. Achieving this is challenging, with current alloys containing antibacterial elements being too stiff. Here, we report a novel Ti-Nb-Au alloy that contains appreciable concentrations of an antibacterial element, is free from the deleterious omega phase, has an exceptionally low elastic modulus (38.4 GPa) and high strain recoverability. These results indicate that the Ti-Nb-Au system has promise for biomedical applications, warranting further investigation and development.
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Dec 2023
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