Faraday Discussions最新文献

{"title":"Synchrotron X-ray nanoprobe and correlative electron microscopy reveal the role of surface chemistry of self-assembling peptides in calcium phosphate nucleation†","authors":"Reham Gonnah, Julia E. Parker, Robert P. W. Davies and Maisoon Al-Jawad","doi":"10.1039/D5FD00017C","DOIUrl":"10.1039/D5FD00017C","url":null,"abstract":"<p >A biomimetic peptide (P<small>₁₁</small>-4), which is predominantly negatively-charged, facilitates the nucleation of hydroxyapatite (HAp). P<small>₁₁</small>-4 self-assembles into fibrils <em>via</em> β-sheet formation, creating a 3D-gel-network. Here, X-ray nanoimaging and correlative scanning electron microscopy (SEM) investigated P<small>₁₁</small>-4's surface chemistry and its ability to nucleate HAp in the absence of the 3D-gel-network. P<small>₁₁</small>-4 was deposited on silicon nitride (SiN) windows, which were immersed in a mineralising solution (MS) and then mapped using nano-X-ray fluorescence (n-XRF) and differential phase contrast imaging at the hard X-ray nanoprobe beamline (I14) at Diamond Light Source. Elemental calcium and phosphorus maps were extracted using n-XRF, and compared with and without P<small>₁₁</small>-4. The windows were subsequently mapped using SEM and Energy Dispersive Spectroscopy (EDS) to confirm the morphology and elemental compositions of the formed structures. The calcium : phosphorus ratios were calculated to identify the phases formed. P<small>₁₁</small>-4 increased the calcium and phosphorus signals with time in MS compared to the control (without P<small>₁₁</small>-4). After 12 hours in MS, calcium ions accumulated on the deposited β-sheets, attracting phosphorus ions at later time points. From the morphology in the images and EDS analysis, the spherical calcium phosphate (CaP) structures appeared to be amorphous, indicating the formation of precursors, likely amorphous CaP, at early time points. In the presence of P<small>₁₁</small>-4, these structures grew and fused into larger CaP formations over time, unlike in the control. Nano-imaging techniques highlighted that P<small>₁₁</small>-4's surface chemistry accelerates the kinetics and controls the initial CaP crystallisation process, resulting in an amorphous CaP phase.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 132-150"},"PeriodicalIF":3.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00017c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing enameloid shark chemistry at the nanoscale†","authors":"Alberto Perez-Huerta, Eshita Samajpati and Gabriela A. Farfan","doi":"10.1039/D5FD00019J","DOIUrl":"10.1039/D5FD00019J","url":null,"abstract":"<p >Shark teeth are considered excellent bio-archives because of their high abundance and preservation potential. Chemical proxies recorded by the teeth enameloid layers are used to interpret ecological and environmental parameters throughout the geological record. The use of these proxies relies on the assumption that biomineralization processes for enameloid formation have remained constant during shark evolution. Here, we test such an assumption by comparing the chemical composition at the nanoscale, using the technique of atom probe tomography (APT), of enameloid in modern and fossil shark teeth. Results indicate that there are clear differences in the chemistry at the core and inter-crystalline grain boundaries of fluorapatite crystals. These boundaries are enriched in strontium in all shark teeth, whereas there are differences in the distribution of magnesium, sodium, and iron. Teeth of the modern shark <em>Isurus oxyrinchus</em> have magnesium and sodium distributed at the inter-crystalline grain boundaries. Teeth of Eocene fossil sharks, <em>Striatolamia macrota</em> and <em>Macrorhizodus praecursor</em>, have a unique distribution of iron, at the inter-crystalline boundaries, and sodium, at the core of the crystals. This observation may indicate that biomineralization processes resulting in enameloid formation are not constant across the phylogeny of sharks. Overall, our findings strongly suggest that the enameloid content and distribution of magnesium, iron, strontium, and sodium are highly controlled by biomineralization processes. The role of magnesium and sodium seems to be similar in mammalian enamel and shark enameloid formation. Yet, nanoscale chemical differences, such as the presence of strontium in tooth enameloid, are likely associated to functional morphology.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 151-165"},"PeriodicalIF":3.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144126253","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":"Biomineral displays systematic spatially varying crystallographic properties in fibrolamellar bone as revealed by position resolved X-ray diffraction","authors":"Adrian Rodriguez-Palomo, Peter Alling Strange Vibe, Mads Ry Vogel Jørgensen and Henrik Birkedal","doi":"10.1039/D5FD00030K","DOIUrl":"10.1039/D5FD00030K","url":null,"abstract":"<p >Bone contains diverse structures. In fast-growing large animals, fibrolamellar bone is formed first and is then gradually replaced by remodelled bone with secondary osteons. Using position-resolved X-ray diffraction and X-ray fluorescence as a 2D multimodal microscopy technique, the nature of biomineral nanocrystals is investigated in bovine bone. Systematic spatial variations are found, for example, with the crystallite size increasing with distance from the bone growth front. The growth front is found to be sharply enriched in Zn, which is speculated to be related to the presence of metal-containing enzymes. Upon remodelling, the formed secondary osteons have a lower degree of mineralization, different lattice constants, and smaller nanocrystal sizes than the primary bone. The results underline the need for spatially resolved techniques for understanding bone biomineralization.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 116-131"},"PeriodicalIF":3.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179764","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":"Bone mineralization and the effects of elevated osteopontin: from symmetry-breaking foci to 3D space-filling tessellation†","authors":"Joseph Deering, Daniel J. Buss, Roland Kröger, Hojatollah Vali, Maureen J. Lagos, Natalie Reznikov and Marc D. McKee","doi":"10.1039/D5FD00013K","DOIUrl":"10.1039/D5FD00013K","url":null,"abstract":"<p >At the nanoscale, lamellar bone tissue mineralization ensues <em>via</em> heteronucleation of small mineral foci within the osteoid. The foci grow to produce a mature, volume-filling tessellation pattern at the micrometer-scale. Mineralization-inhibiting osteopontin (OPN) mediates this bone mineralization pathway and, eventually, the microscale properties of bone tissue. Using 2D and 3D electron microscopy, here we have assessed how the abundance of OPN can affect nanoscale mineralization, mineral ripening, and microscale patterning of mineral in normal wild-type mouse bone, and we compare that to mutant mouse models having elevated OPN (<em>Fgf23</em><small>^−/−</small> and <em>Hyp</em> mice). When OPN is elevated, volume-filling mineral tessellation was incomplete (showing a four-fold increase in mineral surface area in the vicinity of the mineralization front in <em>Hyp</em> bone). Immunogold labeling showed excessive OPN in the foci, suggesting an arrest of their growth and an interruption of the pathway towards microscale tessellation. In <em>Fgf23</em><small>^−/−</small> mice, electron tomography and 3D focused ion beam–scanning electron microscopy (FIB-SEM) imaging of mineral foci show instances of core–shell morphology with crystalline mineral confined to the focus interior, and an amorphous nanogranular texture persisting in the outer shell. Electron energy-loss spectroscopy, which is sensitive to nanoscale elemental composition, showed a lower Ca/P ratio at the periphery of <em>Hyp</em> foci, consistent with a more amorphous mineral character, suggesting that OPN may play a role in delaying the amorphous-to-crystalline transition. These aspects of nanoscale mineral maturation in mutant mice having elevated OPN implicate this protein as a fine-tuning regulator of mineralization kinetics, mineral composition, and mechanical properties of bone.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 406-429"},"PeriodicalIF":3.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12123585/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144172063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional imaging of vasculature and forming quail femur using cryo-correlative light and electron microscopy (cryo-CLEM)","authors":"Anne Seewald, Jingxiao Zhong, Macarena Siri, Peter Fratzl and Emeline Raguin","doi":"10.1039/D5FD00022J","DOIUrl":"10.1039/D5FD00022J","url":null,"abstract":"<p >Bone mineralization during embryonic development requires the transport and deposition of an enormous amount of mineral precursors. In avian embryos, blood vessels play a dual role in this context: facilitating the demineralization of the eggshell to supply calcium and other minerals on the one hand, and mediating their deposition into the developing skeleton on the other. Understanding the interface between blood vessels and the surrounding tissues is therefore crucial for unraveling the mechanisms underlying biomineralization. However, visualizing this interface poses significant challenges and requires imaging methods that preserve the ultrastructure in a close-to-native state. Here we present a detailed methodology for a cryogenic correlative light and electron microscopy (cryo-CLEM) workflow to investigate the transport of mineral precursors in blood vessels of the femur of quail embryos during bone development. To achieve this, we use a fluorophore-conjugated antibody to label endothelial cells, which form the inner lining of blood vessels and which mediate exchanges between the bloodstream and developing tissues. This approach enables precise localization of blood vessels through fluorescence microscopy, which is subsequently correlated with 3D high-resolution electron microscopy using Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM). This methodology allows imaging of a sufficient volume to observe both the lumen of the blood vessels and the surrounding matrix, providing deeper insights into calcium transport and bone mineralization during quail embryogenesis.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 430-445"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00022j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling attainment in Fairbanks, Alaska, for the wintertime PM2.5 24-hour non-attainment area using the CMAQ (community multi-scale air quality) model†","authors":"Deanna Huff, Tom Carlson, Lakshmi Pradeepa Vennam, Chao-Jung Chien, Kathleen Fahey, Robert Gilliam and Nick Czarnecki","doi":"10.1039/D4FD00158C","DOIUrl":"10.1039/D4FD00158C","url":null,"abstract":"&lt;p &gt;Fairbanks Alaska has some of the highest recorded levels of fine particulate matter (PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt;) in the United States (U.S.), exceeding health-based standards since 2009. The National Ambient Air Quality Standard (NAAQS) in the U.S. for 24 h PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt; is 35 μg m&lt;small&gt;&lt;sup&gt;−3&lt;/sup&gt;&lt;/small&gt; with a 24 h averaging time and takes the form of the 98th percentile averaged over three years; the three-year average is called a design value. Monitored PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt; level design values have been as high as 135 μg m&lt;small&gt;&lt;sup&gt;−3&lt;/sup&gt;&lt;/small&gt; or almost 4 times higher than the health-based standard. The current monitored PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt; value for 2021–2023 is 56 μg m&lt;small&gt;&lt;sup&gt;−3&lt;/sup&gt;&lt;/small&gt;. Fairbanks winters have strong temperature inversions, trapping pollutants near the ground and leading to elevated concentrations of PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt; and its precursor gases. The two largest species component contributors to PM&lt;small&gt;&lt;sub&gt;2.5&lt;/sub&gt;&lt;/small&gt; in Fairbanks are organic carbon and sulfate. Control strategies have focused on reducing organic carbon through wood-stove measures and SO&lt;small&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/small&gt; through fuel sulfur reductions. State Implementation Plans (SIPs) are mandatory plans that demonstrate the most expeditious path to reaching the health-based standard. In previous SIPs, the Alaska Department of Environmental Conservation (ADEC) based attainment demonstrations on an outdated modeling platform, emissions inventory, meteorological data, and episodes. Recent updates include upgrading to the CMAQ (Community Multi-Scale Air Quality) model version 5.3.3+ and updated Weather Research and Forecast (WRF) meteorology resulting from a collaboration with the United States Environmental Protection Agency Office of Research and Development (EPA-ORD) and recent Alaska Layered Pollution and Chemical Analysis (ALPACA) studies. In addition, there have been updates to the emissions inventory (survey, census, parcel and home-heating energy demand model) for space heating and other pre-processing models. The changes have resulted in improved model performance in representing stable boundary layers in meteorology and Model Performance Evaluation (MPE) of secondary sulfate. Modeled secondary sulfate went from underpredicting 88% of the observed sulfate values using the previous modeling platform, to improved sulfate predictions with only a 2.5% Normalized Mean Bias (NMB) and 40% Normalized Mean Error (NME). Using the sulfur tracking method, CMAQ modeling suggests that in Fairbanks, 60% of the sulfate is primary, and 40% is secondary on average for our wintertime modeling period. The modeled primary and secondary fractions of sulfate are corroborated by Moon &lt;em&gt;et al.&lt;/em&gt; 2024 (&lt;em&gt;ACS ES&amp;T Air&lt;/em&gt;, 2024, &lt;strong&gt;1&lt;/strong&gt;, 139–149), showing 62% of the ambient measured sulfate particles were primary and 38% were secondary in Fairbanks, during the ALPACA field","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 234-264"},"PeriodicalIF":3.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555386","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":"Nanobeam-scanning X-ray fluorescence microscopy reveals the elemental composition of dense intracellular bodies in biomineralizing coccolithophores†","authors":"Daniel M. Chevrier, Shristy Gautam and André Scheffel","doi":"10.1039/D5FD00021A","DOIUrl":"10.1039/D5FD00021A","url":null,"abstract":"<p >Coccolithophore microalgae intracellularly produce nanostructured calcitic platelets, known as coccoliths, through a biologically-controlled mineralization process. Mature coccoliths are secreted to the cell surface and assembled into a shell that envelops the cell. The large-scale global production of coccoliths, followed by their sedimentation to the ocean floor, significantly contributes to carbon cycling. Despite progress in understanding the biomineralization pathway of coccoliths, we are still limited in our ability to predict how future climate conditions will impact coccolith formation and thus ocean carbon fluxes. Investigating coccolith biomineralization at the single-cell level is therefore critical to advance our understanding but remains challenging since current imaging techniques lack the combined spatial and temporal resolution coupled with element-specific detection to follow processes <em>in situ</em>. In light of this gap, nanobeam-scanning X-ray fluorescence microscopy (nano-XRF) in the hard X-ray regime is employed here to investigate the intracellular elemental distribution of the coccolithophore <em>Gephyrocapsa huxleyi</em> (formerly <em>Emiliania huxleyi</em>) achieving a resolution of 100 nm and elemental detection from phosphorus (P) to zinc (Zn). Calcium- and phosphorus-rich intracellular bodies, previously proposed to be involved in coccolith biomineralization, were observed in cells initially prepared <em>ex situ</em> by drying. Interestingly, nano-XRF imaging reveals metal species (<em>e.g.</em>, Mn, Fe, Zn) within these bodies that were not detected in earlier studies, suggesting multiple biological roles for these structures. Moving towards native-state imaging, <em>G. huxleyi</em> was then imaged in the hydrated state using a dedicated liquid cell device. Measurements were performed on <em>G. huxleyi</em> cells both with and without coccolith shell in sea water medium and compared to those of dried cells, demonstrating comparable image quality. The future potential and limitations of liquid cell nano-XRF imaging for coccolithophores and other microorganisms are further discussed.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 251-268"},"PeriodicalIF":3.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00021a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D Calcium carbonate polymorphs imaging with stimulated Raman scattering in biominerals","authors":"Hamadou Dicko, Jéremie Vidal-Dupiol, Denis Saulnier, Eric Tambutté, Alexander Venn, Sylvie Tambutté, Virginie Chamard and Julien Duboisset","doi":"10.1039/D5FD00025D","DOIUrl":"10.1039/D5FD00025D","url":null,"abstract":"<p >We present a highly sensitive coherent Raman microscopy approach, which allows for the tridimensional (3D) imaging of a series of carbonate polymorphs in marine organisms. CaCO<small>₃</small> biomineralization occurs from the transformation of metastable amorphous precursors and other crystalline phases into a final crystalline phase. Understanding biomineralization pathways requires identifying this physico-chemical temporal sequence. Our approach exploits the different vibrational signatures of amorphous calcium carbonate, aragonite, calcite, Mg-calcite or hemi-hydrated calcium carbonate. This optical method enables the production of spatially and spectrally resolved images of the different compounds. When applied on the growing edge of post-mortem samples of both <em>Pinctada margaritifera</em> pearl oyster shell and <em>Stylophora pistillata</em> coral, it allows for inferring a temporal crystallisation sequence. We thus highlight the existence of intermediate crystalline phases, involving magnesian calcite or hemi-hydrated calcium carbonate, respectively.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 286-297"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144186082","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":"Supramolecular peptidic dopants for inducing photoconductivity and mechanical tunability in digital light processable hydrogels†","authors":"Harrison C. Jeong, Yuyao Kuang, Ze-Fan Yao and Herdeline Ann M. Ardona","doi":"10.1039/D5FD00031A","DOIUrl":"10.1039/D5FD00031A","url":null,"abstract":"<p >This work presents a strategy for generating composite hydrogels bearing photoconductive conduits held by supramolecular interactions that are compatible with digital light processing (DLP) printing. Conductive polymers are typically processed with organic solvents as the film, yet if used as biomaterials, excitable cells often require matching with the mechanical and structural properties of their native, aqueous three-dimensional (3-D) microenvironment. Here, we utilize peptide-functionalized porphyrin units capable of self-assembling into photoconductive nanostructures with defined nanomorphologies under aqueous conditions. In addition to the DXXD peptide arms (X = V, F), the sequence variants studied here include a peptidic moiety bearing allyloxycarbonyl (alloc) groups that can serve as crosslinking sites of the acrylate-based monomers that ultimately form the base 3-D covalent network for the hydrogels. We investigate the impact of pre-templating polymeric gelators with supramolecular assemblies <em>vs.</em> printing a dispersed peptide–porphyrin in a polymer composite, specifically, the potential impact of the morphologies of the supramolecular additives or “dopants” on the resulting mechanical property, conductivity, and printability of the hydrogels, comprised of a hybrid between acrylated polymers and supramolecular peptide–porphyrin assemblies. Lastly, we demonstrate the role of photophysical properties that emerge from peptide-tuned porphyrin assemblies as a photoabsorber additive that influences the printing outcomes of the composite hydrogel. Overall, we present a covalent-supramolecular composite hydrogelator system where the self-assembled networks offer a pathway for energy transport and mechanical reinforcement/dissipation at the same time, leading to the formation of a hydrogel with optoelectronic, mechanical, and printable behavior that can be influenced by self-assembled dopants.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"260 ","pages":" 192-203"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143953308","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":"Autoinduction through the coupling of nucleation-dependent self-assembly of a supramolecular gelator and a reaction network†","authors":"Jamie S. Foster and Gareth O. Lloyd","doi":"10.1039/D5FD00016E","DOIUrl":"10.1039/D5FD00016E","url":null,"abstract":"<p >Autocatalytic and/or self-replicating systems are important aspects of understanding the link between living systems (origins of life) and chemical networks. As a result, many scientists around the world are attempting to better understand these phenomena by producing chemical networks and linking them to self-assembly and pathway complexity (systems chemistry). We present here a superficially autocatalytic, self-replicating system that utilises dynamic imine chemistry coupled with self-assembling supramolecular hydrogelation kinetics driven by a nucleation autocatalytic cycle (autoinduction). The dynamic nature of the imine bond within water allows “error-checking” correction and driving of the imine equilibrium to the starting materials, but when coupled to the self-assembly process it gives rise to one reaction product from a possible thirteen intermediates and/or products (of a mixed four-step reaction). This product represents a thermodynamic minimum within the system's and reaction network's energy landscape. The self-assembly in solution of the replicator results in the formation of supramolecular polymers, which would normally markedly reduce the catalytic efficiency of the system if a template mechanism of autocatalysis is in play. By overcoming the limiting effects of the self-assembly process, it is possible to demonstrate exponential growth in replicator concentration once nucleation has occurred. It is only once the completed imine can undergo non-reversible tautomerisation that the product is prevented from reacting with water. We thus suggest that this sigmoidal kinetic characterisation is not inherent to autocatalysis kinetics (lowering reaction barriers and/or templating), but rather a result of the nucleation-based assembly allowing for intermediates to be prevented from reacting with water in a water-deficient environment (an autoinduction autocatalytic mechanism). Not only does this study provide a basis with which to explore aspects of self-replication connected with self-assembly, but it also explores how nucleation and self-assembly growth can play a crucial role in self-replication. By controlling the kinetics of the autocatalytic chemical reaction at one end of the hierarchical assembly process, we can influence the physical properties of the supramolecular gel at the other end. This may have wide-ranging applications with <em>in-situ</em>-formed small molecular gelators where specific mechanical properties (rheology) are desired.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"260 ","pages":" 82-93"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00016e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}