Faraday Discussions最新文献

{"title":"Spiers Memorial Lecture: A retrospective view on the non-classical features revealed by advanced imaging of biominerals.","authors":"Laurie Gower","doi":"10.1039/d5fd00054h","DOIUrl":"https://doi.org/10.1039/d5fd00054h","url":null,"abstract":"<p><p>Biominerals have unique morphologies and complex hierarchical microstructures, so the study of biomineralization has benefited greatly from the development of advanced microscopy and characterization tools. In my career, I witnessed a revolutionary change in the theories relating to biomineral formation mechanisms. While much of this was due to the advancements in imaging techniques, I present an argument to suggest that <i>in vitro</i> model systems played an important role in steering the biomineral community toward resolving the non-classical crystallization processes that are now understood to lie at the foundation of biological calcification processes. This retrospective review will discuss two case studies that are classic examples of biominerals, mollusk nacre for the invertebrates, and bone for the vertebrates. It will therefore be biased given my group's discovery of the Polymer-Induced Liquid-Precursor (PILP) process, which serendipitously emulated the morphologies and textures of these (and other) biominerals. The goal, however, is not to repeat that body of literature, but rather to demonstrate how the use of model systems has helped decipher mineralization mechanisms, and to propose new ideas that could be explored to further advance the field.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144289361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convergence in biomineralization patterns across animal eggshells.","authors":"Gerben Debruyn, Seung Choi, Jessica L Dobson, Yana Maudens, Karen De Clerck, Matthew D Shawkey, Shukang Zhang, Liliana D'Alba","doi":"10.1039/d5fd00028a","DOIUrl":"https://doi.org/10.1039/d5fd00028a","url":null,"abstract":"<p><p>Shelled eggs are key components of animal reproduction on land, evolving independently in distant lineages of terrestrial animals including nematodes, gastropods, annelids, arthropods and chordates. They perform critical functions such as the exchange of gases between embryo and the environment, desiccation avoidance and protection from harmful radiation, microbial infection and mechanical damage. A core mechanism behind eggshell multifunctionality is the incorporation of biominerals (mainly calcium carbonate and calcium phosphate) into the shell. Very little is known about eggshell structure in invertebrates, but some recent pioneering studies have proposed that similar mineralization patterns may have evolved convergently in eggshells of pulmonate gastropods, some insects, and vertebrates. However, because a detailed characterization of the structural and chemical composition of invertebrate eggshells is not available, it has not been possible to test this hypothesis. Here, we use computed tomography, electron microscopy, electron backscatter diffraction analyses, atomic force microscopy, spectroscopy, and histochemistry to characterize and compare microstructure and chemical composition of pulmonate gastropod, insect and vertebrate eggshells. These techniques revealed the universal presence of an organic matrix in mineralized eggshells. However, disparities in the distribution of calcium throughout the shell, crystallographic orientation that appears random in invertebrates (but not vertebrates), and presence of different calcium types including the rare and unstable vaterite highlight divergence whose functional significance should be the subject of future study.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imaging the orientation of hydroxyapatite crystallites across full mouse femora.","authors":"Thorbjørn Erik Køppen Christensen, Takeshi Moriishi, Toshihisa Komori","doi":"10.1039/d5fd00009b","DOIUrl":"https://doi.org/10.1039/d5fd00009b","url":null,"abstract":"<p><p>Imaging the orientations of crystallites in bone requires the usage of synchrotron X-ray radiation, which is a limited resource for researchers. Thus scans have historically been limited to either small regions or few samples. In the present study, we scan 16 full frontal cross sections of mouse femora. This makes it possible to study structure, orientation, and composition, statistically across many different bones and animals, while preserving the structural context. From the following analysis, we can deduce that while the trabecular bone in the shaft has a larger fraction of oriented crystallites than other regions in the bone, the oriented fraction is more well aligned in the cortical bone in the shaft compared to other regions in the bone. We also see that the crystallites in the cortical and trabecular bone are longer than those in the femoral head and the condyle. The study also shows a larger Sr content in the cortical bone compared to other regions, and a larger Zn content in the femoral head compared to other regions of the bones. This study shows the need for and possibility of scanning larger regions to understand bioinorganic materials.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication and characterization of phosphoinositide containing asymmetric vesicles in physiological salt.","authors":"Trevor A Paratore, Alonzo H Ross, Arne Gericke","doi":"10.1039/d4fd00191e","DOIUrl":"https://doi.org/10.1039/d4fd00191e","url":null,"abstract":"<p><p>Phosphoinositide (PIPs) lipids mediate a broad range of physiological functions by attracting proteins at specific time points to distinct cellular sites. Many of these processes are associated with the local accumulation of PIPs and PIP/protein signaling platform formation. Studies aimed at determining the physicochemical underpinnings of PIP domain formation have been limited to model systems that exhibited the same lipid composition in both bilayer leaflets. However, biological membranes are asymmetric, and it is desirable to develop an experimental approach that allows for the fabrication of lipid model systems with a non-symmetric lipid bilayer, <i>i.e.</i>, a membrane mimic that exhibits a PIP containing lipid mixture in one leaflet and a different lipid composition in the opposing leaflet. We adapted the previously introduced hemifusion method for the fabrication of asymmetric Giant Unilamellar Vesicles (aGUVs) for the fabrication of aGUVs with phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P₂) in a physiological ionic strength buffer solution. The general method involved the bivalent cation-initiated fusion of a symmetric GUV (sGUV) with solid-supported lipid bilayers, which leads to the exchange of the outer leaflet of the sGUV. We find that initiating the hemifusion with 6 mM Ca²⁺ leads to a low yield and quality of the aGUVs. We attribute this to macroscopic Ca²⁺/PI(4,5)P₂ domain formation of the solid support lipid bilayer (SLB), which leads to the interaction of the sGUVs with regions enriched in PI(4,5)P₂ (domain) and other areas that are void of the PIP lipid. Using 6 mM Mg²⁺ as the initiator instead led to an improvement in terms of yield and aGUV quality. The best results were obtained when using 1 mM Mg²⁺. We are introducing several data analysis approaches that allow for the identification of aGUVs that exhibit high quality in terms of the outer leaflet exchange and composition of the two aGUV leaflets.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144256853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Membrane potential fluctuations and water asymmetry on plasma cell and model lipid membranes: origins, implications and properties.","authors":"Zhi Li, Iwona Swiderska, Lena Dalifoski, Seonwoo Lee, Nelson Alonso Correa-Rojas, David Roesel, Maksim Eremchev, Mischa Flor, Orly B Tarun, Arianna Marchioro, Sylvie Roke","doi":"10.1039/d4fd00197d","DOIUrl":"https://doi.org/10.1039/d4fd00197d","url":null,"abstract":"<p><p>Membrane potential fluctuations have previously been detected using second harmonic (SH) water imaging on neuronal cells and model lipid bilayer membranes. We report that such fluctuations are also visible when membrane potential-sensitive fluorophores are used as contrast agents, and fluctuations are imaged on both free-standing lipid membranes (FLMs) and on the plasma membranes of neuroblastoma cells. We show that upon K⁺ depolarization, non-uniform recovery responses occur across cells and within single cells. We discuss the origins and implications of such fluctuations, and investigate the molecular-level details of membrane potential distributions on FLMs and compare it to those on giant unilamellar vesicles (GUVs). SH water imaging shows that the hydrated part of lipid membranes is most likely composed of regions having a diffuse double layer, and other regions having an additional condensed double layer, with a high concentration of ions/ionic groups. In terms of transmembrane potential distributions, FLMs and GUVs show similar signatures, as expected from electrostatics. Comparing passive ion transport, FLMs and GUVs of identical composition behave differently, with GUVs being more permeable for proton transport (∼20×). This is likely caused by differences in the hydrophobic cores of the membranes, which create different energetic barriers for the proton transport.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystallisation in biomineral mollusc shell studied by 3D Bragg ptychography.","authors":"Tilman A Grünewald, Peng Li, Julien Duboisset, Julius Nouet, Oier Bikondoa, Jeremie Vidal-Dupiol, Denis Saulnier, Manfred Burghammer, Virginie Chamard","doi":"10.1039/d5fd00020c","DOIUrl":"https://doi.org/10.1039/d5fd00020c","url":null,"abstract":"<p><p>Biomineralisation integrates complex biologically assisted physico-chemical processes leading to an extraordinary diversity of calcareous biomineral crystalline architectures, in intriguing contrast with the consistent presence of a submicrometric granular structure. While the repeated observation of amorphous calcium carbonate is interpreted as a precursor to the crystalline phase, the crystalline transition mechanisms are poorly understood. Access to the crystalline architecture at the mesoscale, <i>i.e.</i>, over a few granules, is key to building realistic crystallisation models. Here we exploit three-dimensional X-ray Bragg ptychography microscopy to provide a series of nanoscale maps of the crystalline structure within the \"single-crystalline\" prism of the prismatic layer of a <i>Pinctada margaritifera</i> shell. The mesocrystalline organisation exhibits several micrometre-sized iso-oriented/iso-strained crystalline domains, the detailed studies of which reveal the presence of crystalline coherence domains ranging from 130 to 550 nm in size. The further increase in the lattice parameter with the size of the coherence domain likely results from the crystallisation mechanism, pointing towards a maturation process occurring after the initial amorphous-to-crystalline transition.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144232738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative structural analysis of stereom polymorphs in the sea urchin test.","authors":"Ronald Seidel, Konrad Handrich, Marie Albéric, Jonathan Perrin, Derk Joester, Yael Politi, Luca Bertinetti","doi":"10.1039/d5fd00033e","DOIUrl":"https://doi.org/10.1039/d5fd00033e","url":null,"abstract":"<p><p>The fenestrated ultrastructure of the sea urchin endoskeleton has attracted the attention of researchers in different fields due to its morphological complexity and crystallographic properties. Microscopic calcitic trabeculae form an intricate bicontinuous network, called the stereom. The stereom exhibits a wide variation of pore patterns, but is essentially a single calcite crystal (mono-crystalline). The polymorphism and crystal orientation in the skeletons of sea urchins have both been previously extensively described, mostly for taxonomical reasons and for mechanical studies. Moreover, while the resemblance of the stereom architecture to constant-mean-curvature (CMC) structures has been pointed out, a quantitative description and critical analysis is still lacking. Here, we use synchrotron micro-computed tomography to capture the three-dimensional (3D) architecture of the skeletal stereom in sea urchins for morphological quantification. By characterising the different stereom types, we define a data processing pipeline that allows inter-individual and interspecies comparison of stereom architectures, with implications for sea urchin taxonomy, mechanics, and skeletal growth. We further show that the various stereom morphologies are bicontinuous CMC surfaces that are unconstrained by crystallography. Our results highlight the properties of the soft tissue filling the stereom pore space in defining the shape of sea urchin biocalcite.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Millisecond-time-scale controlled freeze-quench for solute-intermediate analysis by solid-state NMR.","authors":"Ieva Goldberga, Trevys Chanal, Tristan Georges, Guillaume P Laurent, Thierry Azaïs","doi":"10.1039/d5fd00032g","DOIUrl":"https://doi.org/10.1039/d5fd00032g","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Crystallization is a fundamental process in biomineralization, yet its complexity increases significantly in non-classical pathways of nucleation and growth, where numerous intermediates exist between free ions in solution and the final crystalline phase. Characterization of such intermediates can be delicate, as some processes can proceed very fast, inducing a short temporal window for their characterization. The problem is particularly true for the so-called prenucleation species, for which this difficulty is made worse due to their solubility, nanometric size and highly dynamic nature. In this communication, we introduce an innovative approach based on the \"trapping\" of reactive intermediates in a vitreous matrix, inspired by cryo-TEM sample preparation but adapted specifically to solid-state NMR characterization. This approach enables time-resolved analysis, since the aging time of the mineralization reaction is controlled on the millisecond time-scale using a dedicated stopped-flow device. The cryo-fixation is achieved by spraying the reacting solution into cold liquid isopentane at -145 °C, and the NMR rotors are filled with specifically designed packing tools, ensuring the control of the low temperature during the whole process. Finally, the cryo-fixed solution can be studied &lt;i&gt;via&lt;/i&gt; low-temperature solid-state NMR by acquiring time-resolved NMR spectra as snapshots of the ongoing reaction. First, we show that phosphate solutions can be efficiently vitrified using this protocol and studied &lt;i&gt;via&lt;/i&gt; low-temperature &lt;sup&gt;31&lt;/sup&gt;P solid-state NMR at -120 °C. We demonstrate that the &lt;sup&gt;31&lt;/sup&gt;P chemical-shift interaction of cryo-quenched solutions varies with the pH, allowing us to distinguish the different phosphate species coexisting in solution (PO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;3-&lt;/sup&gt;, HPO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;, H&lt;sub&gt;2&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;and H&lt;sub&gt;3&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt;) based on their chemical shift anisotropy patterns, which are characteristic of their protonation degree. The determination of the proportion of each species at varying pH levels enables us to construct a speciation diagram under our experimental conditions. We observe that the \"apparent p&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;a&lt;/sub&gt;\" values, &lt;i&gt;i.e.&lt;/i&gt;, the pH values for each chemical equilibrium, are slightly influenced by the low temperature, and possibly by the preparation conditions. Finally, we demonstrate that our method can be applied to study fast calcium phosphate crystallization, revealing the early stages of amorphous calcium phosphate (ACP) nucleation within just 20 ms of reaction time, as shown by &lt;sup&gt;31&lt;/sup&gt;P ssNMR. Importantly, the described methodology is the first step towards studying fast out-of-equilibrium solutions through trapping and then studying transient intermediate species &lt;i&gt;via&lt;/i&gt; solid-state NMR. Indeed, proper freeze-quenching prevents the transient species from transforming and preserves their native environment, such as hydration, pH, or ionic","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploiting nanoprobe X-ray techniques for imaging of biomineralisation; chemical, structural and <i>in situ</i> opportunities.","authors":"Jessica M Walker, Miguel A Gomez-Gonzalez, Johannes Ihli, Julia E Parker","doi":"10.1039/d5fd00037h","DOIUrl":"https://doi.org/10.1039/d5fd00037h","url":null,"abstract":"<p><p>Advances in X-ray nanoprobe beamlines at synchrotrons across the world present exciting opportunities for rich multimodal imaging of biomineral structures and their formation processes. The combination of techniques provides a sensitive probe of both chemistry and structure, making X-ray nanoprobes an important tool for investigating crystallite growth and orientations, interfaces, and assembly of building blocks into hierarchical structures. A discussion of these capabilities is presented with reference to recent examples using a range of nanoprobe imaging techniques for investigating enamel structure, as well as coccolith properties. Key opportunities for the use of X-ray nanoprobes lie in exploiting the penetrating power and coherence properties of synchrotron X-rays in order to image <i>in situ</i> processes or apply coherent diffractive imaging techniques to obtain higher resolutions. To this end initial results demonstrating the observation of calcium phosphate mineralisation, in a liquid environment, using nano-X-ray fluorescence mapping are presented, and the role of X-ray dose and beam induced effects is considered. Finally novel results from tomographic ptychography imaging of <i>Mytilus edulis</i> mussel shell calcite prisms are discussed, where the segmentation of the phase density into organic and mineral content gives insights into the mechanisms underlying mineral prism formation and the role of the organic matrix in biomineralisation.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into non-contact reflectance IR mapping of teeth.","authors":"Franco Lizzi, Hamza Elfarraj, Oleksandra Marushchenko, Ole Lenz, Peter Lasch, Ljiljana Puskar, Ioanna Mantouvalou, Paul Zaslansky","doi":"10.1039/d5fd00026b","DOIUrl":"https://doi.org/10.1039/d5fd00026b","url":null,"abstract":"<p><p>Teeth are made of highly mineralized tissues that withstand years of daily usage. Their mechanical properties have been studied at all length scales with ageing, but mainly small areas have been the focus of high-sensitivity chemical property quantification. A comprehensive, spatially resolved examination across centimeter sized tooth specimens is needed to expand our comprehension of young <i>versus</i> aged teeth. Specular Reflectance Fourier Transform Infrared Spectroscopy (srFTIR) is a nondestructive microscopy technique that can be used to characterize the chemical composition of mineralized surfaces. This technique provides spatially resolved chemical absorption information, making it useful to study both organics and mineral in visibly accessible tooth tissues. Highly polished dehydrated cross-sectional surfaces of bovine and human teeth were srFTIR imaged, and spectra were processed using a Kramers-Kronig transformation to generate absorbance-like chemical maps. Results are comparable with the well-established FTIR Transmission and Attenuated Total Reflection (ATR) methods. Maps of multiple <i>ν</i>₃-phosphate vibrations, <i>ν</i>₂-carbonate, and amide I reveal insights into structural and chemical variations across dentine. Young bovine teeth exhibited many chemical and structural similarities to old, partially sclerotic human teeth, affirming their use as proxies in dental research. This work highlights the capability of specular reflection infrared spectroscopy imaging to reveal spatial chemical information and expand our understanding of tooth microstructure and composition variations.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}