1
|
Raynes JK, Mata J, Wilde KL, Carver JA, Kelly SM, Holt C. Structure of biomimetic casein micelles: Critical tests of the hydrophobic colloid and multivalent-binding models using recombinant deuterated and phosphorylated β-casein. J Struct Biol X 2024; 9:100096. [PMID: 38318529 PMCID: PMC10840362 DOI: 10.1016/j.yjsbx.2024.100096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 02/07/2024] Open
Abstract
Milk contains high concentrations of amyloidogenic casein proteins and is supersaturated with respect to crystalline calcium phosphates such as apatite. Nevertheless, the mammary gland normally remains unmineralized and free of amyloid. Unlike κ-casein, β- and αS-caseins are highly effective mineral chaperones that prevent ectopic and pathological calcification of the mammary gland. Milk invariably contains a mixture of two to five different caseins that act on each other as molecular chaperones. Instead of forming amyloid fibrils, several thousand caseins and hundreds of nanoclusters of amorphous calcium phosphate combine to form fuzzy complexes called casein micelles. To understand the biological functions of the casein micelle its structure needs to be understood better than at present. The location in micelles of the highly amyloidogenic κ-casein is disputed. In traditional hydrophobic colloid models, it, alone, forms a stabilizing surface coat that also determines the average size of the micelles. In the recent multivalent-binding model, κ-casein is present throughout the micelle, in intimate contact with the other caseins. To discriminate between these models, a range of biomimetic micelles was prepared using a fixed concentration of the mineral chaperone β-casein and nanoclusters of calcium phosphate, with variable concentrations of κ-casein. A biomimetic micelle was also prepared using a highly deuterated and in vivo phosphorylated recombinant β-casein with calcium phosphate and unlabelled κ-casein. Neutron and X-ray scattering experiments revealed that κ-casein is distributed throughout the micelle, in quantitative agreement with the multivalent-binding model but contrary to the hydrophobic colloid models.
Collapse
Affiliation(s)
- Jared K. Raynes
- CSIRO Agriculture & Food, 671 Sneydes Road, Werribee, VIC 3031, Australia
- All G Foods, Waterloo, NSW 2006, Australia
| | - Jitendra Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
- School of Chemistry, University of New South Wales, Sydney 2052, Australia
| | - Karyn L. Wilde
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - John A. Carver
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia
| | - Sharon M. Kelly
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Carl Holt
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
2
|
McDonogh DP, Gale JD, Raiteri P, Gebauer D. Redefined ion association constants have consequences for calcium phosphate nucleation and biomineralization. Nat Commun 2024; 15:3359. [PMID: 38637527 PMCID: PMC11026415 DOI: 10.1038/s41467-024-47721-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 04/10/2024] [Indexed: 04/20/2024] Open
Abstract
Calcium orthophosphates (CaPs), as hydroxyapatite (HAP) in bones and teeth are the most important biomineral for humankind. While clusters in CaP nucleation have long been known, their speciation and mechanistic pathways to HAP remain debated. Evidently, mineral nucleation begins with two ions interacting in solution, fundamentally underlying solute clustering. Here, we explore CaP ion association using potentiometric methods and computer simulations. Our results agree with literature association constants for Ca2+ and H2PO4-, and Ca2+ and HPO42-, but not for Ca2+ and PO43- ions, which previously has been strongly overestimated by two orders of magnitude. Our data suggests that the discrepancy is due to a subtle, premature phase separation that can occur at low ion activity products, especially at higher pH. We provide an important revision of long used literature constants, where association of Ca2+ and PO43- actually becomes negligible below pH 9.0, in contrast to previous values. Instead, [CaHPO4]0 dominates the aqueous CaP speciation between pH ~6-10. Consequently, calcium hydrogen phosphate association is critical in cluster-based precipitation in the near-neutral pH regime, e.g., in biomineralization. The revised thermodynamics reveal significant and thus far unexplored multi-anion association in computer simulations, constituting a kinetic trap that further complicates aqueous calcium phosphate speciation.
Collapse
Affiliation(s)
- David P McDonogh
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany
| | - Julian D Gale
- Curtin Institute for Computation and School of Molecular and Life Sciences, Curtin University, P.O. Box U1987, Perth, WA, 6845, Australia
| | - Paolo Raiteri
- Curtin Institute for Computation and School of Molecular and Life Sciences, Curtin University, P.O. Box U1987, Perth, WA, 6845, Australia.
| | - Denis Gebauer
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany.
| |
Collapse
|
3
|
Zhang TL. Pseudo-equilibrium equations for calcium phosphate precipitation with multi-unit particles. Phys Chem Chem Phys 2023; 26:581-593. [PMID: 38086635 DOI: 10.1039/d3cp03700b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The chemistry underlying bone mineral formation in vertebrates is the reaction of calcium phosphate precipitation. In a near-neutral solution, an amorphous phase and hydroxyapatite nanoparticles appear successively, and the reaction system containing either of the two kinds of precipitates is in a non-equilibrium state. Here, we propose a pseudo-equilibrium approach to the solution chemistry of the precipitation reactions. We employed two series of reaction systems, collected samples at various stages, and analyzed the solution chemistry data on the basis of a simplified model of reaction. We derived two types of pseudo-equilibrium equations from the two series, respectively. These equations reveal the existence of multiple structural units in a precipitate particle and correlate the ionic product with the surface proportion per structural unit (m). The surface proportion, in turn, is related to the whole particle through a particle-surface equation. Notably, the two types of pseudo-equilibrium constants have the common expression of "Kd = ionic product" if the number of the structural units (u) is large enough. Together, these findings have revealed some aspects of the non-equilibrium thermodynamics of precipitation reactions, indicating the solution chemistry route to the equilibrium state. The concept of the multi-unit particle may shed new light on the study of precipitation reactions of other slightly soluble electrolytes. And the relationship between the ionic product and the surface proportion of a structural unit is not only fundamental in chemistry, but may also apply to non-equilibrium systems in nature and biology, such as marine sedimentation, human vascular calcification, and bone mineral metabolism.
Collapse
Affiliation(s)
- Tian-Lan Zhang
- Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, 38 Xueyuan Road, Beijing 100191, P. R. China.
| |
Collapse
|
4
|
Aretxabaleta XM, López-Zorrilla J, Etxebarria I, Manzano H. Multi-step nucleation pathway of C-S-H during cement hydration from atomistic simulations. Nat Commun 2023; 14:7979. [PMID: 38042823 PMCID: PMC10693585 DOI: 10.1038/s41467-023-43500-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 11/10/2023] [Indexed: 12/04/2023] Open
Abstract
The Calcium Silicate Hydrate (C-S-H) nucleation is a crucial step during cement hydration and determines to a great extent the rheology, microstructure, and properties of the cement paste. Recent evidence indicates that the C-S-H nucleation involves at least two steps, yet the underlying atomic scale mechanism, the nature of the primary particles and their stability, or how they merge/aggregate to form larger structures is unknown. In this work, we use atomistic simulation methods, specifically DFT, evolutionary algorithms (EA), and Molecular Dynamics (MD), to investigate the structure and formation of C-S-H primary particles (PPs) from the ions in solution, and then discuss a possible formation pathway for the C-S-H nucleation. Our simulations indicate that even for small sizes the most stable clusters encode C-S-H structural motifs, and we identified a C4S4H2 cluster candidate to be the C-S-H basic building block. We suggest a formation path in which small clusters formed by silicate dimers merge into large elongated aggregates. Upon dehydration, the C-S-H basic building blocks can be formed within the aggregates, and eventually crystallize.
Collapse
Affiliation(s)
- Xabier M Aretxabaleta
- Fisika saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa z/g, 48940, Leioa, Basque Country, Spain.
| | - Jon López-Zorrilla
- Fisika saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa z/g, 48940, Leioa, Basque Country, Spain
| | - Iñigo Etxebarria
- Fisika saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa z/g, 48940, Leioa, Basque Country, Spain
- EHU Quantum Center, Euskal Herriko Unibertsitatea, UPV/EHU, Leioa, Spain
| | - Hegoi Manzano
- Fisika saila, Euskal Herriko Unibertsitatea UPV/EHU, Sarriena Auzoa z/g, 48940, Leioa, Basque Country, Spain.
| |
Collapse
|
5
|
Water-Mediated attraction between Like-charged species involved in calcium phosphate nucleation. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
|
6
|
Lauer AR, Hellmann R, Montes-Hernandez G, Findling N, Ling WL, Epicier T, Fernandez-Martinez A, Van Driessche AES. Deciphering strontium sulfate precipitation via Ostwald's rule of stages: From prenucleation clusters to solution-mediated phase tranformation. J Chem Phys 2023; 158:054501. [PMID: 36754828 DOI: 10.1063/5.0136870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Multiple-step nucleation pathways have been observed during mineral formation in both inorganic and biomineral systems. These pathways can involve precursor aqueous species, amorphous intermediates, or metastable phases. Despite the widespread occurrence of these processes, elucidating the precise nucleation steps and the transformation mechanisms between each step remains a challenging task. Using a suite of potentiometric, microscopic, and spectroscopic tools, we studied the nucleation pathway of SrSO4 as a function of the physico-chemical solution parameters. Our observations reveal that below a threshold supersaturation, nucleation is driven by bound species, akin to the prenucleation cluster model, which directly leads to the formation of the stable phase celestine, SrSO4. At higher supersaturations, this situation is altered, with nucleation dominated by the consumption of free ions. Importantly, this change in nucleation mechanism is coupled to the formation of a hemihydrate metastable phase, SrSO4 · 1/2H2O, which eventually transforms into celestine, adhering to Ostwald's rule of stages. This transformation is a solution-mediated process, also occurring in the presence of a fluid film and is controlled by the physico-chemical parameters of the surrounding environment. It proceeds through the dissolution of the metastable phase and the de novo crystallization of the final phase. Overall, our results reveal that ion association taking place during the prenucleation stage dictates whether the nucleation pathway goes through an intermediate phase or not. This also underlines that although Ostwald's rule of stages is a common process, it is not a prerequisite for mineral formation-even in systems where it can occur.
Collapse
Affiliation(s)
- A R Lauer
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| | - R Hellmann
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| | - G Montes-Hernandez
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| | - N Findling
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| | - W L Ling
- Université Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
| | - T Epicier
- Université de Lyon, Université Claude Bernard Lyon1, IRCELYON, umr CNRS 5256, 69626 Villeurbanne Cedex, France
| | - A Fernandez-Martinez
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| | - A E S Van Driessche
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France
| |
Collapse
|
7
|
Gao A, Remsing RC, Weeks JD. Local Molecular Field Theory for Coulomb Interactions in Aqueous Solutions. J Phys Chem B 2023; 127:809-821. [PMID: 36669139 DOI: 10.1021/acs.jpcb.2c06988] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Coulomb interactions play a crucial role in a wide array of processes in aqueous solutions but present conceptual and computational challenges to both theory and simulations. We review recent developments in an approach addressing these challenges─local molecular field (LMF) theory. LMF theory exploits an exact and physically suggestive separation of intermolecular Coulomb interactions into strong short-range and uniformly slowly varying long-range components. This allows us to accurately determine the averaged effects of the long-range components on the short-range structure using effective single particle fields and analytical corrections, greatly reducing the need for complex lattice summation techniques used in most standard approaches. The simplest use of these ideas in aqueous solutions leads to the short solvent (SS) model, where both solvent-solvent and solute-solvent Coulomb interactions have only short-range components. Here we use the SS model to give a simple description of pairing of nucleobases and biologically relevant ions in water.
Collapse
Affiliation(s)
- Ang Gao
- Department of Physics, Beijing University of Posts and Telecommunications, Beijing, China 100876
| | - Richard C Remsing
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - John D Weeks
- Institute for Physical Science and Technology and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
8
|
Roy S, Bocharova V, Stack AG, Bryantsev VS. Nucleation Rate Theory for Coordination Number: Elucidating Water-Mediated Formation of a Zigzag Na 2SO 4 Morphology. ACS APPLIED MATERIALS & INTERFACES 2022; 14:53213-53227. [PMID: 36395432 DOI: 10.1021/acsami.2c17475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Predicting and controlling nanostructure formation during nucleation can pave the way to synthesizing novel energy materials via crystallization. However, such control over nucleation and crystallization remains challenging due to an inadequate understanding of critical factors that govern evolving atomistic structures and dynamics. Herein, we utilize coordination number as a reaction coordinate and rate theory to investigate how sodium sulfate, commonly known as a phase-change energy material, nucleates in a supersaturated aqueous solution. In conjunction with ab initio and force field-based molecular dynamics simulation, the rate theoretical analysis reveals that sodium sulfate from an initially dissolved metastable state transits to a heterogeneous mixture of prenucleated clusters and finally to a large cylindrical zigzag morphology. Measurements of Raman spectra and their ab initio modeling confirm that this nucleated morphology contains a few waters for every sulfate. Rate processes such as solvent exchange and desolvation exhibit high sensitivity to the evolving prenucleation/nucleation structures, providing a means to distinguish between critical nucleation precursors. Desolvation and forming the first-shell interionic coordination structure via monomer-by-monomer addition around sulfates are found to explain the formation of large nuclei. Thus, a detailed understanding of the step-by-step structure formation across scales has been achieved. This can be leveraged to predict nucleation-related structures and dynamics and potentially control the synthesis of novel phase-change materials for energy applications.
Collapse
Affiliation(s)
- Santanu Roy
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee37830, United States
| | - Vera Bocharova
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee37830, United States
| | - Andrew G Stack
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee37830, United States
| | - Vyacheslav S Bryantsev
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee37830, United States
| |
Collapse
|
9
|
Xue Z, Wang X, Xu D. Molecular investigations of the prenucleation mechanism of bone-like apatite assisted by type I collagen nanofibrils: insights into intrafibrillar mineralization. Phys Chem Chem Phys 2022; 24:18931-18942. [PMID: 35916012 DOI: 10.1039/d2cp02573f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bone is a typical inorganic-organic composite material with a multilevel hierarchical organization. In the lowest level of bone tissue, inorganic minerals, which are mainly composed of hydroxyapatite, are mineralized within the type I collagen fibril scaffold. Understanding the crystal prenucleation mechanism and growth of the inorganic phase is particularly important in the design and development of materials with biomimetic nanostructures. In this study, we built an all-atom human type I collagen fibrillar model with a 67 nm overlap/gap D-periodicity. Arginine residues were shown to serve as the dominant cross-linker to stabilize the fibril scaffold. Subsequently, the prenucleation mechanism of collagen intrafibrillar mineralization was investigated using a molecular dynamics approach. Considering the physiological pH of the human body (i.e., ∼7.4), HPO42- was initially used to simulate the protonation state of the phosphate ions. Due to the spatially constrained effects resulting from the overlap/gap structure of the collagen fibrils, calcium phosphate clusters formed mainly inside the hole zone but with different spatial distributions along the long axis direction; this indicated that the nucleation of calcium phosphate may be highly site-selective. Furthermore, the model containing both HPO42- and PO43- in the solution phase formed significantly larger clusters without any change in the nucleation sites. This phenomenon suggests that the existence of PO43- is beneficial for the mineralization process, and so the conversion of HPO42- to PO43- was considered a critical step during mineralization. Finally, we summarize the nucleation mechanism for collagen intrafibrillar mineralization, which could contribute to the fabrication of mineralized collagen biomimetic materials.
Collapse
Affiliation(s)
- Zhiyu Xue
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, P. R. China.
| | - Xin Wang
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, P. R. China.
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, P. R. China.
| |
Collapse
|
10
|
Gebauer D, Gale JD, Cölfen H. Crystal Nucleation and Growth of Inorganic Ionic Materials from Aqueous Solution: Selected Recent Developments, and Implications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107735. [PMID: 35678091 DOI: 10.1002/smll.202107735] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/07/2022] [Indexed: 05/27/2023]
Abstract
In this review article, selected, latest theoretical, and experimental developments in the field of nucleation and crystal growth of inorganic materials from aqueous solution are highlighted, with a focus on literature after 2015 and on non-classical pathways. A key point is to emphasize the so far underappreciated role of water and solvent entropy in crystallization at all stages from solution speciation through to the final crystal. While drawing on examples from current inorganic materials where non-classical behavior has been proposed, the potential of these approaches to be adapted to a wide-range of systems is also discussed, while considering the broader implications of the current re-assessment of pathways for crystallization. Various techniques that are suitable for the exploration of crystallization pathways in aqueous solution, from nucleation to crystal growth are summarized, and a flow chart for the assignment of specific theories based on experimental observations is proposed.
Collapse
Affiliation(s)
- Denis Gebauer
- Leibniz University Hannover, Institute of Inorganic Chemistry, Callinstr. 9, 30167, Hannover, Germany
| | - Julian D Gale
- Curtin Institute for Computation/The Institute for Geoscience Research (TiGER), School of Molecular and Life Sciences, Curtin University, PO Box U1987, Perth, Western Australia, 6845, Australia
| | - Helmut Cölfen
- University of Konstanz, Physical Chemistry, Universitätsstr. 10, 78465, Konstanz, Germany
| |
Collapse
|
11
|
Zhang J, Zhang W, Wang L. In Situ Observation of Dicalcium Phosphate Monohydrate Formation and Phase Transformation. J Phys Chem B 2022; 126:4881-4888. [PMID: 35749263 DOI: 10.1021/acs.jpcb.2c01627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Calcium orthophosphates (CaPs), as important minerals in biomineralization and biomedicine, have attracted wide attention. Dicalcium phosphate monohydrate (DCPM, CaHPO4·H2O), the recently discovered crystalline CaP phase, has a higher metastability than dihydrate (DCPD, CaHPO4·2H2O) and anhydrate (DCPA, CaHPO4), which may lead to many potential applications in functional biomaterial development. However, the preparation of large-sized DCPM and the underlying mechanisms of its formation and phase evolution remain unclear. Herein, for the first time, we propose a method to prepare micrometer-sized DCPM under an acidic water-methanol mixture and using in situ time-resolved atomic force microscopy further explore its crystallization via dissolution of an acidic amorphous calcium phosphate. In support of the potential role of DCPM as the biomaterial, we demonstrate that DCPM can quickly evolve into more stable octacalcium phosphate in a near-physiological solution. This work provides a mechanistic understanding of the formation and phase transformation of DCPM, which may serve as a basis for subsequent synthesis and application of DCPM as functional biomaterials.
Collapse
Affiliation(s)
- Jing Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| |
Collapse
|
12
|
Experimentally probing ionic solutions in single-digit nanoconfinement. J Colloid Interface Sci 2022; 614:396-404. [DOI: 10.1016/j.jcis.2022.01.128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 01/01/2023]
|
13
|
Casting a bright light on Ostwald's rule of stages. Proc Natl Acad Sci U S A 2022; 119:2121661119. [PMID: 35131933 PMCID: PMC8851489 DOI: 10.1073/pnas.2121661119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
14
|
Wang Y, Song L, Wang G, Liu H, Jing Z, Zhou Y, Zhu F, Zhang Y. Structure analysis of aqueous Mg(NO 3) 2 solutions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120478. [PMID: 34653851 DOI: 10.1016/j.saa.2021.120478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 10/03/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
An increasing amount of research has investigated whether direct contact ion pairs (CIP) exist in magnesium nitrate solutions. In this work, the relationship between the concentration and microstructure, as well as the details of the ion pair structure in magnesium nitrate solutions were studied by Raman spectroscopy, molecular dynamics (MD) simulations, and density functional theory (DFT) calculations. Component analysis showed that solvent-shared ion pairs (SIPs) and free hydrated ions were the dominant species in dilute solution. SIPs gradually transformed into contact ion pairs as the concentration increased. Complex structures and CIPs were the main species when WSR < 10, and as the concentration further increased, the CIP content gradually decreased, while the number of complex structures gradually increased. MD simulations and DFT calculations provide a new understanding of the structural units of ion pairs in magnesium nitrate solutions. The SIPs and CIPs were mainly composed of cationic triple ion clusters with two magnesium ions and one nitrate ion. The nitrate ion mainly existed as monodentate ligand to form a CIP with the magnesium ion. As the solution concentration increased, triple ion clusters gradually transformed into more complex chain structures. The structural complexity of magnesium nitrate solutions deserves further attention.
Collapse
Affiliation(s)
- Yunxia Wang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lulu Song
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangguo Wang
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongyan Liu
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China
| | - Zhuanfang Jing
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongquan Zhou
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China
| | - Fayan Zhu
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Resources Chemistry of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 81008, China.
| | - Yunhong Zhang
- The Institute of Chemical Physics, School of Science, and School of Aerospace Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
| |
Collapse
|
15
|
Dorozhkin SV. Synthetic amorphous calcium phosphates (ACPs): preparation, structure, properties, and biomedical applications. Biomater Sci 2021; 9:7748-7798. [PMID: 34755730 DOI: 10.1039/d1bm01239h] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amorphous calcium phosphates (ACPs) represent a metastable amorphous state of other calcium orthophosphates (abbreviated as CaPO4) possessing variable compositional but rather identical glass-like physical properties, in which there are neither translational nor orientational long-range orders of the atomic positions. In nature, ACPs of a biological origin are found in the calcified tissues of mammals, some parts of primitive organisms, as well as in the mammalian milk. Manmade ACPs can be synthesized in a laboratory by various methods including wet-chemical precipitation, in which they are the first solid phases, precipitated after a rapid mixing of aqueous solutions containing dissolved ions of Ca2+ and PO43- in sufficient amounts. Due to the amorphous nature, all types of synthetic ACPs appear to be thermodynamically unstable and, unless stored in dry conditions or doped by stabilizers, they tend to transform spontaneously to crystalline CaPO4, mainly to ones with an apatitic structure. This intrinsic metastability of the ACPs is of a great biological relevance. In particular, the initiating role that metastable ACPs play in matrix vesicle biomineralization raises their importance from a mere laboratory curiosity to that of a reasonable key intermediate in skeletal calcifications. In addition, synthetic ACPs appear to be very promising biomaterials both for manufacturing artificial bone grafts and for dental applications. In this review, the current knowledge on the occurrence, structural design, chemical composition, preparation, properties, and biomedical applications of the synthetic ACPs have been summarized.
Collapse
|
16
|
Wang K, Luo F, Wang L, Zhang B, Fan Y, Wang X, Xu D, Zhang X. Biomineralization from the Perspective of Ion Aggregation: Calcium Phosphate Nucleation in the Physiological Environment. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49519-49534. [PMID: 34609125 DOI: 10.1021/acsami.1c15393] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Biomineralization is an important process of bone tissue generation. Calcium (Ca) and phosphate (P) ions aggregate and nucleate under the regulation of biomolecules at the initial mineralization stage. Due to the complexity of the physiological environment, the movement behavior and mineralization mechanism of calcium and phosphate ions, as well as the effect of biomolecules on them, are not clear. In this study, computer simulations and experimental verification were applied to investigate the characteristics of the initial biomineralization from the view of ion aggregation and nucleation. The results prove that P ions play a more important role in mineralization than Ca ions. The guanidyl group and surrounding carboxyl terminal groups are a potential excellent nucleation domain on proteins. The interval distribution of acidic/basic residues on protein is more conductive to the formation of large Ca and P ions clusters. The involvement of protein could increase the probability of hydroxyapatite phase precipitation, especially in the presence of a helical conformation. The detailed information on Ca and P ions behavior provided by the computer simulations is helpful for further understanding the mechanism of biomineralization, which will promote the development of bone repair materials to the biomimetic mineralized materials.
Collapse
Affiliation(s)
- Kefeng Wang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
- Research Center for Material Genome Engineering, Sichuan University, Chengdu 610064, China
| | - Fengxiong Luo
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Ling Wang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Boqing Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Yujiang Fan
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Xin Wang
- Research Center for Material Genome Engineering, Sichuan University, Chengdu 610064, China
- College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Dingguo Xu
- Research Center for Material Genome Engineering, Sichuan University, Chengdu 610064, China
- College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Xingdong Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
- Research Center for Material Genome Engineering, Sichuan University, Chengdu 610064, China
| |
Collapse
|
17
|
Tolmachev D, Mamistvalov G, Lukasheva N, Larin S, Karttunen M. Effects of Amino Acid Side-Chain Length and Chemical Structure on Anionic Polyglutamic and Polyaspartic Acid Cellulose-Based Polyelectrolyte Brushes. Polymers (Basel) 2021; 13:polym13111789. [PMID: 34071693 PMCID: PMC8199235 DOI: 10.3390/polym13111789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 05/25/2021] [Accepted: 05/25/2021] [Indexed: 11/25/2022] Open
Abstract
We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration.
Collapse
Affiliation(s)
- Dmitry Tolmachev
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr. 31, 199004 Petersburg, Russia; (N.L.); (S.L.)
- Correspondence: (D.T.); (M.K.)
| | - George Mamistvalov
- Faculty of Physics, St. Petersburg State University, Petrodvorets, 198504 Petersburg, Russia;
| | - Natalia Lukasheva
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr. 31, 199004 Petersburg, Russia; (N.L.); (S.L.)
| | - Sergey Larin
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr. 31, 199004 Petersburg, Russia; (N.L.); (S.L.)
- Faculty of Physics, St. Petersburg State University, Petrodvorets, 198504 Petersburg, Russia;
| | - Mikko Karttunen
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr. 31, 199004 Petersburg, Russia; (N.L.); (S.L.)
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Department of Applied Mathematics, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- The Centre of Advanced Materials and Biomaterials Research, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B7, Canada
- Correspondence: (D.T.); (M.K.)
| |
Collapse
|
18
|
Avila Salazar DA, Bellstedt P, Miura A, Oi Y, Kasuga T, Brauer DS. Unravelling the dissolution mechanism of polyphosphate glasses by 31P NMR spectroscopy: ligand competition and reactivity of intermediate complexes. Dalton Trans 2021; 50:3966-3978. [PMID: 33646216 DOI: 10.1039/d0dt03381b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphate glass dissolution can be tailored via compositional and subsequent structural changes, which is of interest for biomedical applications such as therapeutic ion delivery. Here, solid-state 31P nuclear magnetic resonance characterisation of 45P2O5-xCaO - (55 -x)Na2O glasses was correlated with dissolution studies using time-dependent liquid 31P NMR spectroscopy and quantitative chemical analysis. Glasses dissolved congruently in aqueous media, and the first dissolution stage was the hydration of phosphate chains. In deionised water and Tris buffer (pH0 7.4 or 7.9), trimetaphosphate rings and orthophosphates were the predominant species in solution, indicating relatively fast degradation. By contrast, long phosphate chains were identified in EDTA (pH0 10.0). Besides pH differences, coordination of phosphate species by metal cations appears to play a catalytic role in the hydrolysis mechanism via turning phosphorus atoms into suitable electrophiles for the subsequent nucleophilic attack by water. Hydrolysis rates were proportional to phosphate complex stability, with stronger complexes for chains than for rings. A competition between solvent and phosphate species for the metal ion occurred in the order EDTA > Tris > deionised water.
Collapse
Affiliation(s)
- Dahiana A Avila Salazar
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Fraunhoferstr. 6, 07743 Jena, Germany.
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
PURPOSE OF REVIEW Calciprotein particles (CPP) are formed in supersaturated solutions of calcium, phosphate and the mineral-binding protein fetuin-A. CPP have garnered considerable interest as potential mediators of mineral stress, but little consideration has been given to their origin, clearance and role in metabolism. RECENT FINDINGS CPP are made whilst buffering the mineral absorbed from the intestine after a meal or during remodelling of bone matrix. The postprandial rise in circulating CPP rise may be sensed by osteoblasts/osteocytes in bone, stimulating the secretion of the master phosphatonin fibroblast growth factor 23. Amorphous calcium phosphate-containing CPP are rapidly cleared by endothelial cells in the liver whereas crystalline apatite-containing CPP are filtered by phagocytic cells of the reticuloendothelial system. Impaired excretory function in kidney disease may lead to accumulation of CPP and its precursors with possible pathological sequalae. Inability to stabilize CPP in fetuin-A-deficiency states can result in intraluminal precipitation and inflammatory cascades if other mineralisation regulatory networks are compromised. SUMMARY CPP allow efficient transport and clearance of bulk calcium phosphate as colloids without risk of precipitation. As circulating factors, CPP may couple dietary mineral exposure with endocrine control of mineral metabolism in bone, signalling the need to dispose of excess phosphate from the body.
Collapse
|
20
|
Yu L, Wei M. Biomineralization of Collagen-Based Materials for Hard Tissue Repair. Int J Mol Sci 2021; 22:944. [PMID: 33477897 PMCID: PMC7833386 DOI: 10.3390/ijms22020944] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 12/23/2022] Open
Abstract
Hydroxyapatite (HA) reinforced collagen fibrils serve as the basic building blocks of natural bone and dentin. Mineralization of collagen fibrils play an essential role in ensuring the structural and mechanical functionalities of hard tissues such as bone and dentin. Biomineralization of collagen can be divided into intrafibrillar and extrafibrillar mineralization in terms of HA distribution relative to collagen fibrils. Intrafibrillar mineralization is termed when HA minerals are incorporated within the gap zone of collagen fibrils, while extrafibrillar mineralization refers to the minerals that are formed on the surface of collagen fibrils. However, the mechanisms resulting in these two types of mineralization still remain debatable. In this review, the evolution of both classical and non-classical biomineralization theories is summarized. Different intrafibrillar mineralization mechanisms, including polymer induced liquid precursor (PILP), capillary action, electrostatic attraction, size exclusion, Gibbs-Donnan equilibrium, and interfacial energy guided theories, are discussed. Exemplary strategies to induce biomimetic intrafibrillar mineralization using non-collagenous proteins (NCPs), polymer analogs, small molecules, and fluidic shear stress are discussed, and recent applications of mineralized collagen fibers for bone regeneration and dentin repair are included. Finally, conclusions are drawn on these proposed mechanisms, and the future trend of collagen-based materials for bone regeneration and tooth repair is speculated.
Collapse
Affiliation(s)
- Le Yu
- Department of Chemical and Biomolecular Engineering, Ohio University, Athens, OH 45701, USA;
| | - Mei Wei
- Department of Chemical and Biomolecular Engineering, Ohio University, Athens, OH 45701, USA;
- Department of Mechanical Engineering, Ohio University, Athens, OH 45701, USA
| |
Collapse
|
21
|
Structural Biology of Calcium Phosphate Nanoclusters Sequestered by Phosphoproteins. CRYSTALS 2020. [DOI: 10.3390/cryst10090755] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Biofluids that contain stable calcium phosphate nanoclusters sequestered by phosphopeptides make it possible for soft and hard tissues to co-exist in the same organism with relative ease. The stability diagram of a solution of nanocluster complexes shows how the minimum concentration of phosphopeptide needed for stability increases with pH. In the stable region, amorphous calcium phosphate cannot precipitate. Nevertheless, if the solution is brought into contact with hydroxyapatite, the crystalline phase will grow at the expense of the nanocluster complexes. The physico-chemical principles governing the formation, composition, size, structure, and stability of the complexes are described. Examples are given of complexes formed by casein, osteopontin, and recombinant phosphopeptides. Application of these principles and properties to blood serum, milk, urine, and resting saliva is described to show that under physiological conditions they are in the stable region of their stability diagram and so cannot cause soft tissue calcification. Stimulated saliva, however, is in the metastable region, consistent with its role in tooth remineralization. Destabilization of biofluids, with consequential ill-effects, can occur when there is a failure of homeostasis, such as an increase in pH without a balancing increase in the concentration of sequestering phosphopeptides.
Collapse
|
22
|
Cruz MAE, Ferreira CR, Tovani CB, de Oliveira FA, Bolean M, Caseli L, Mebarek S, Millán JL, Buchet R, Bottini M, Ciancaglini P, Paula Ramos A. Phosphatidylserine controls calcium phosphate nucleation and growth on lipid monolayers: A physicochemical understanding of matrix vesicle-driven biomineralization. J Struct Biol 2020; 212:107607. [PMID: 32858148 DOI: 10.1016/j.jsb.2020.107607] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/15/2020] [Accepted: 08/19/2020] [Indexed: 12/12/2022]
Abstract
Bone biomineralization is an exquisite process by which a hierarchically organized mineral matrix is formed. Growing evidence has uncovered the involvement of one class of extracellular vesicles, named matrix vesicles (MVs), in the formation and delivery of the first mineral nuclei to direct collagen mineralization. MVs are released by mineralization-competent cells equipped with a specific biochemical machinery to initiate mineral formation. However, little is known about the mechanisms by which MVs can trigger this process. Here, we present a combination of in situ investigations and ex vivo analysis of MVs extracted from growing-femurs of chicken embryos to investigate the role played by phosphatidylserine (PS) in the formation of mineral nuclei. By using self-assembled Langmuir monolayers, we reconstructed the nucleation core - a PS-enriched motif thought to trigger mineral formation in the lumen of MVs. In situ infrared spectroscopy of Langmuir monolayers and ex situ analysis by transmission electron microscopy evidenced that mineralization was achieved in supersaturated solutions only when PS was present. PS nucleated amorphous calcium phosphate that converted into biomimetic apatite. By using monolayers containing lipids extracted from native MVs, mineral formation was also evidenced in a manner that resembles the artificial PS-enriched monolayers. PS-enrichment in lipid monolayers creates nanodomains for local increase of supersaturation, leading to the nucleation of ACP at the interface through a multistep process. We posited that PS-mediated nucleation could be a predominant mechanism to produce the very first mineral nuclei during MV-driven bone/cartilage biomineralization.
Collapse
Affiliation(s)
- Marcos A E Cruz
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil
| | - Claudio R Ferreira
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil
| | - Camila B Tovani
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil
| | | | - Maytê Bolean
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil
| | - Luciano Caseli
- Institute of Environmental, Chemical and Pharmaceutical Sciences - Federal University of Sao Paulo, Brazil
| | - Saida Mebarek
- Universite de Lyon, ICBMS UMR 5246 CNRS, Villeurbanne, France
| | - José Luis Millán
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Rene Buchet
- Universite de Lyon, ICBMS UMR 5246 CNRS, Villeurbanne, France
| | - Massimo Bottini
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Pietro Ciancaglini
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil.
| | - Ana Paula Ramos
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, FFCLRP - Universidade de São Paulo - Departamento de Química, Brazil.
| |
Collapse
|
23
|
Raiteri P, Schuitemaker A, Gale JD. Ion Pairing and Multiple Ion Binding in Calcium Carbonate Solutions Based on a Polarizable AMOEBA Force Field and Ab Initio Molecular Dynamics. J Phys Chem B 2020; 124:3568-3582. [PMID: 32259444 DOI: 10.1021/acs.jpcb.0c01582] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The speciation of calcium carbonate in water is important to the geochemistry of the world's oceans and has ignited significant debate regarding the mechanism by which nucleation occurs. Here, it is vital to be able to quantify the thermodynamics of ion pairing versus higher order association processes in order to distinguish between possible pathways. Given that it is experimentally challenging to quantify such species, here we determine the thermodynamics for ion pairing and multiple binding of calcium carbonate species using bias-enhanced molecular dynamics. In order to examine the uncertainties underlying these results, we derived a new polarizable force field for both calcium carbonate and bicarbonate in water based on the AMOEBA model to compare against our earlier rigid ion model, both of which are further benchmarked against ab initio molecular dynamics for the ion pair. Both force fields consistently indicate that the association of calcium carbonate ion pairs to form larger species is stable, though with an equilibrium constant that is lower than for ion pairing itself.
Collapse
Affiliation(s)
- Paolo Raiteri
- Curtin Institute for Computation/The Institute for Geoscience Research (TIGeR), School of Molecular and Life Sciences, Curtin University, P.O. Box U1987, Perth, Western Australia 6845, Australia
| | - Alicia Schuitemaker
- Curtin Institute for Computation/The Institute for Geoscience Research (TIGeR), School of Molecular and Life Sciences, Curtin University, P.O. Box U1987, Perth, Western Australia 6845, Australia
| | - Julian D Gale
- Curtin Institute for Computation/The Institute for Geoscience Research (TIGeR), School of Molecular and Life Sciences, Curtin University, P.O. Box U1987, Perth, Western Australia 6845, Australia
| |
Collapse
|
24
|
Golda-Cepa M, Riedlová K, Kulig W, Cwiklik L, Kotarba A. Functionalization of the Parylene C Surface Enhances the Nucleation of Calcium Phosphate: Combined Experimental and Molecular Dynamics Simulations Approach. ACS APPLIED MATERIALS & INTERFACES 2020; 12:12426-12435. [PMID: 32098467 PMCID: PMC7497617 DOI: 10.1021/acsami.9b20877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Interactions at the solid-body fluid interfaces play a vital role in bone tissue formation at the implant surface. In this study, fully atomistic molecular dynamics (MD) simulations were performed to investigate interactions between the physiological components of body fluids (Ca2+, HPO42-, H2PO4-, Na+, Cl-, and H2O) and functionalized parylene C surface. In comparison to the native parylene C (-Cl surface groups), the introduction of -OH, -CHO, and -COOH surface groups significantly enhances the interactions between body fluid ions and the polymeric surface. The experimentally observed formation of calcium phosphate nanocrystals is discussed in terms of MD simulations of the calcium phosphate clustering. Surface functional groups promote the clustering of calcium and phosphate ions in the following order: -OH > -CHO > -Cl (parent parylene C) ≈ -COO-. This promoting role of surface functional groups is explained as stimulating the number of Ca2+ and HPO42- surface contacts as well as ion chemisorption. The molecular mechanism of calcium phosphate cluster formation at the functionalized parylene C surface is proposed.
Collapse
Affiliation(s)
- Monika Golda-Cepa
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Kamila Riedlová
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
- Faculty
of Science, Department of Physical and Macromolecular Chemistry, Charles University in Prague, Hlavova 2030, 12840 Prague 2, Czech Republic
| | - Waldemar Kulig
- Department
of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Lukasz Cwiklik
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - Andrzej Kotarba
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| |
Collapse
|
25
|
Abstract
This work provides a clearer picture for non-classical nucleation by revealing the presence of various intermediates using advanced characterization techniques.
Collapse
Affiliation(s)
- Biao Jin
- Physical Sciences Division
- Pacific Northwest National Laboratory
- Richland
- USA
- Department of Chemistry
| | - Zhaoming Liu
- Department of Chemistry
- Zhejiang University
- Hangzhou
- China
| | - Ruikang Tang
- Department of Chemistry
- Zhejiang University
- Hangzhou
- China
| |
Collapse
|