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Christie JK. Review: understanding the properties of amorphous materials with high-performance computing methods. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220251. [PMID: 37211037 DOI: 10.1098/rsta.2022.0251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/20/2023] [Indexed: 05/23/2023]
Abstract
Amorphous materials have no long-range order in their atomic structure. This makes much of the formalism for the study of crystalline materials irrelevant, and so elucidating their structure and properties is challenging. The use of computational methods is a powerful complement to experimental studies, and in this paper we review the use of high-performance computing methods in the simulation of amorphous materials. Five case studies are presented to showcase the wide range of materials and computational methods available to practitioners in this field. This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.
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Affiliation(s)
- J K Christie
- Department of Materials, Loughborough University, Loughborough LE11 3TU, UK
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2
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Pantaleone S, Rimola A, Sodupe M. Canonical, deprotonated, or zwitterionic? II. A computational study on amino acid interaction with the TiO 2(110) rutile surface: comparison with the anatase (101) surface. Phys Chem Chem Phys 2020; 22:16862-16876. [PMID: 32666992 DOI: 10.1039/d0cp01429j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption of 11 amino acids (Gly, Leu, Met, Phe, Ser, Cys, Glu, Gln, Arg, Lys, and His) on the TiO2(110) rutile surface is investigated adopting a theoretical approach, using the PBE-D2* functional as implemented in the periodic VASP code. The adsorption of the amino acids is considered in their canonical, deprotonated and zwitterionic forms. For all cases, the most stable adsorption mode adopts a bidentate (O,O) binding with surface undercoordinated Ti atoms, in agreement with previous experimental and computational studies using glycine as a test case. Such a binding mode is possible due to the surface morphology, because the Ti-Ti distances match very well with the carboxylic O-O distance. The most stable adsorption states are the deprotonated and the zwitterionic ones, the canonical one lying significantly above in energy. The relative stability between the deprotonated and the zwitterionic states results in a delicate trade-off among dative interactions (O, N, and S atoms of the amino acids with Ti atoms of the surface), H-bond interactions, dispersive forces and, to a lesser extent, steric hindrance of the amino acidic lateral chains. Finally, the difference in the amino acid adsorption between the (110) rutile and the (101) anatase surfaces is discussed both from the energetic and surface morphological standpoints, highlighting the larger reactivity of the rutile polymorph in adsorbing and deprotonating the amino acids compared with the anatase one.
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Affiliation(s)
- S Pantaleone
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain.
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3
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Montecarlo Simulation and HAXPES Analysis of Organosilane Segregation in Titania Xerogel Films; Towards a Generic Surface Chemofunctionalization Process. SURFACES 2020. [DOI: 10.3390/surfaces3030026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The formation of xerogels implies a sequence of hydrolysis and condensation reactions, which are intricate to analyze in heteromolecular sols. We analyze by probabilistic Montecarlo methods the development of hybrid organosilane–titania xerogels and illustrate how partial charges of the reacting molecules can help estimating relative probabilities for the condensation of the molecules. Since the condensation rate of Ti alkoxides is much higher than the corresponding rate of Si alkoxides (especially if bearing a non-hydrolizable group), by imposing a fast condensation process in agreement with low pH kinetics, the process leads to a surface segregation of the organosilane. The simulation results are compared with results of characterization of thin condensates of two different organosilanes within a titanium–isopropoxide matrix. Non-destructive in-depth profiles were obtained by hard x-ray photoelectron spectroscopy, which can resolve through estimation of Si and specific moieties of the organosilane molecules the progress of the condensation. These results are relevant for the generalization of chemo-functionalization processes by kinetic demixing of organosilanes, which have myriad applications in biomedicine and biotechnology.
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4
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Kargozar S, Montazerian M, Fiume E, Baino F. Multiple and Promising Applications of Strontium (Sr)-Containing Bioactive Glasses in Bone Tissue Engineering. Front Bioeng Biotechnol 2019; 7:161. [PMID: 31334228 PMCID: PMC6625228 DOI: 10.3389/fbioe.2019.00161] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 06/20/2019] [Indexed: 12/22/2022] Open
Abstract
Improving and accelerating bone repair still are partially unmet needs in bone regenerative therapies. In this regard, strontium (Sr)-containing bioactive glasses (BGs) are highly-promising materials to tackle this challenge. The positive impacts of Sr on the osteogenesis makes it routinely used in the form of strontium ranelate (SR) in the clinical setting, especially for patients suffering from osteoporosis. Therefore, a large number of silicate-, borate-, and phosphate-based BGs doped with Sr and produced in different shapes have been developed and characterized, in order to be used in the most advanced therapeutic strategies designed for the management of bone defects and injuries. Although the influence of Sr incorporation in the glass is debated regarding the obtained physicochemical and mechanical properties, the biological improvements have been found to be substantial both in vitro and in vivo. In the present study, we provide a comprehensive overview of Sr-containing glasses along with the current state of their clinical use. For this purpose, different types of Sr-doped BG systems are described, including composites, coatings and porous scaffolds, and their applications are discussed in the light of existing experimental data along with the significant challenges ahead.
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Affiliation(s)
- Saeid Kargozar
- Tissue Engineering Research Group (TERG), Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Maziar Montazerian
- Center for Research, Technology and Education in Vitreous Materials, Federal University of São Carlos, São Carlos, Brazil
| | - Elisa Fiume
- Department of Applied Science and Technology, Institute of Materials Physics and Engineering, Politecnico di Torino, Turin, Italy
| | - Francesco Baino
- Department of Applied Science and Technology, Institute of Materials Physics and Engineering, Politecnico di Torino, Turin, Italy
- Interuniversity Center for the Promotion of the 3Rs Principles in Teaching and Research, Italy
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Fernandes HR, Gaddam A, Rebelo A, Brazete D, Stan GE, Ferreira JMF. Bioactive Glasses and Glass-Ceramics for Healthcare Applications in Bone Regeneration and Tissue Engineering. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E2530. [PMID: 30545136 PMCID: PMC6316906 DOI: 10.3390/ma11122530] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/04/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022]
Abstract
The discovery of bioactive glasses (BGs) in the late 1960s by Larry Hench et al. was driven by the need for implant materials with an ability to bond to living tissues, which were intended to replace inert metal and plastic implants that were not well tolerated by the body. Among a number of tested compositions, the one that later became designated by the well-known trademark of 45S5 Bioglass® excelled in its ability to bond to bone and soft tissues. Bonding to living tissues was mediated through the formation of an interfacial bone-like hydroxyapatite layer when the bioglass was put in contact with biological fluids in vivo. This feature represented a remarkable milestone, and has inspired many other investigations aiming at further exploring the in vitro and in vivo performances of this and other related BG compositions. This paradigmatic example of a target-oriented research is certainly one of the most valuable contributions that one can learn from Larry Hench. Such a goal-oriented approach needs to be continuously stimulated, aiming at finding out better performing materials to overcome the limitations of the existing ones, including the 45S5 Bioglass®. Its well-known that its main limitations include: (i) the high pH environment that is created by its high sodium content could turn it cytotoxic; (ii) and the poor sintering ability makes the fabrication of porous three-dimensional (3D) scaffolds difficult. All of these relevant features strongly depend on a number of interrelated factors that need to be well compromised. The selected chemical composition strongly determines the glass structure, the biocompatibility, the degradation rate, and the ease of processing (scaffolds fabrication and sintering). This manuscript presents a first general appraisal of the scientific output in the interrelated areas of bioactive glasses and glass-ceramics, scaffolds, implant coatings, and tissue engineering. Then, it gives an overview of the critical issues that need to be considered when developing bioactive glasses for healthcare applications. The aim is to provide knowledge-based tools towards guiding young researchers in the design of new bioactive glass compositions, taking into account the desired functional properties.
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Affiliation(s)
- Hugo R Fernandes
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Anuraag Gaddam
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Avito Rebelo
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Daniela Brazete
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - George E Stan
- National Institute of Materials Physics, RO-077125 Magurele, Romania.
| | - José M F Ferreira
- Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
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6
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Kapoor S, Youngman RE, Zakharchuk K, Yaremchenko A, Smith NJ, Goel A. Structural and Chemical Approach toward Understanding the Aqueous Corrosion of Sodium Aluminoborate Glasses. J Phys Chem B 2018; 122:10913-10927. [DOI: 10.1021/acs.jpcb.8b06155] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Saurabh Kapoor
- Department of Materials Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Randall E. Youngman
- Science and Technology Division, Corning Incorporated, Painted Post, New York 14870, United States
| | - Kiryl Zakharchuk
- CICECO—Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Aleksey Yaremchenko
- CICECO—Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Nicholas J. Smith
- Science and Technology Division, Corning Incorporated, Painted Post, New York 14870, United States
| | - Ashutosh Goel
- Department of Materials Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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7
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Pedone A, Chen X, Hill RG, Karpukhina N. Molecular Dynamics Investigation of Halide-Containing Phospho-Silicate Bioactive Glasses. J Phys Chem B 2018; 122:2940-2948. [DOI: 10.1021/acs.jpcb.8b00547] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alfonso Pedone
- Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy
| | - Xiaojing Chen
- Xiangya Stomatological Hospital & School of Stomatology, Central South University, Changsha, Hunan 410078, P.R. China
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Robert G. Hill
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Natalia Karpukhina
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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Lopes JH, Fonseca EMB, Mazali IO, Magalhães A, Landers R, Bertran CA. Facile and innovative method for bioglass surface modification: Optimization studies. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 72:86-97. [DOI: 10.1016/j.msec.2016.11.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/10/2016] [Accepted: 11/13/2016] [Indexed: 10/20/2022]
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Bramhill J, Ross S, Ross G. Bioactive Nanocomposites for Tissue Repair and Regeneration: A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:E66. [PMID: 28085054 PMCID: PMC5295317 DOI: 10.3390/ijerph14010066] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 12/09/2016] [Accepted: 12/24/2016] [Indexed: 11/17/2022]
Abstract
This review presents scientific findings concerning the use of bioactive nanocomposites in the field of tissue repair and regeneration. Bioactivity is the ability of a material to incite a specific biological reaction, usually at the boundary of the material. Nanocomposites have been shown to be ideal bioactive materials due the many biological interfaces and structures operating at the nanoscale. This has resulted in many researchers investigating nanocomposites for use in bioapplications. Nanocomposites encompass a number of different structures, incorporating organic-inorganic, inorganic-inorganic and bioinorganic nanomaterials and based upon ceramic, metallic or polymeric materials. This enables a wide range of properties to be incorporated into nanocomposite materials, such as magnetic properties, MR imaging contrast or drug delivery, and even a combination of these properties. Much of the classical research was focused on bone regeneration, however, recent advances have enabled further use in soft tissue body sites too. Despite recent technological advances, more research is needed to further understand the long-term biocompatibility impact of the use of nanoparticles within the human body.
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Affiliation(s)
- Jane Bramhill
- Biopolymer Group, Biomaterials Center of Excellence, Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
| | - Sukunya Ross
- Biopolymer Group, Biomaterials Center of Excellence, Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
| | - Gareth Ross
- Biopolymer Group, Biomaterials Center of Excellence, Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
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10
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Tilocca A. Dynamical descriptors of bioactivity: a correlation between chemical durability and ion migration in biodegradable glasses. Phys Chem Chem Phys 2017; 19:6334-6337. [DOI: 10.1039/c6cp07203h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular dynamics simulations reveal the importance of using dynamical descriptors to rationalize and predict the behavior of biomedical glasses.
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Affiliation(s)
- Antonio Tilocca
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
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11
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12
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Côté AS, Cormack AN, Tilocca A. Influence of Calcium on the Initial Stages of the Sol-Gel Synthesis of Bioactive Glasses. J Phys Chem B 2016; 120:11773-11780. [PMID: 27809532 DOI: 10.1021/acs.jpcb.6b09881] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding how calcium interacts with silica sources and influences their polycondensation in aqueous solutions is of central importance for the development of more effective biomaterials by sol-gel approaches. For this purpose, the atomic-scale evolutions of a calcium-containing precursor solution corresponding to a typical sol-gel bioactive glass and of a corresponding Ca-free solution were compared using reactive molecular dynamics simulations. The simulations highlight a significantly faster rate of condensation when calcium is present in the initial solution, resulting in the formation of large and ramified silica clusters within 5 ns, which are absent in the Ca-free system. This different behavior has been analyzed and interpreted in terms of the Ca-induced nanosegregation in calcium-rich and silica-rich regions, which promotes the condensation reactions within the latter. By identifying a possible mechanism behind the limited incorporation of calcium in the silica nanoclusters formed in the early stages of the sol-gel process, these results could guide further studies aimed at identifying favorable experimental conditions to enhance initial calcium incorporation and thus produce sol-gel biomaterials with improved properties.
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Affiliation(s)
- Alexander S Côté
- Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
| | - Alastair N Cormack
- New York State College of Ceramics, Alfred University , Alfred, New York 14802, United States
| | - Antonio Tilocca
- Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
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13
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Zahid S, Shah AT, Jamal A, Chaudhry AA, Khan AS, Khan AF, Muhammad N, Rehman IU. Biological behavior of bioactive glasses and their composites. RSC Adv 2016. [DOI: 10.1039/c6ra07819b] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
This review summarizes current developments in improving the biological behavior of bioactive glasse and their composites.
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Affiliation(s)
- Saba Zahid
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Asma Tufail Shah
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Arshad Jamal
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Aqif Anwar Chaudhry
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Abdul Samad Khan
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Ather Farooq Khan
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Nawshad Muhammad
- Interdisciplinary Research Centre in Biomedical Materials
- COMSATS Institute of Information Technology
- Lahore
- Pakistan
| | - Ihtesham ur Rehman
- Department of Material Science and Engineering
- The Kroto Research Institute
- University of Sheffield
- Sheffield S3 7HQ
- UK
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14
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Rimola A, Ugliengo P, Sodupe M. Strained ring motif at silica surfaces: A quantum mechanical study of their reactivity towards protic molecules. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.10.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Mathew R, Stevensson B, Edén M. Na/Ca Intermixing around Silicate and Phosphate Groups in Bioactive Phosphosilicate Glasses Revealed by Heteronuclear Solid-State NMR and Molecular Dynamics Simulations. J Phys Chem B 2015; 119:5701-15. [PMID: 25815412 DOI: 10.1021/acs.jpcb.5b01130] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We characterize the intermixing of network-modifying Na(+)/Ca(2+) ions around the silicate (QSi(n)) and phosphate (QP(n)) tetrahedra in a series of 16 Na2O–CaO–SiO2–P2O5 glasses, whose P content and silicate network connectivity were varied independently. The set includes both bioactive and bioinactive compositions and also encompasses two soda-lime-silicate members devoid of P, as well as two CaO–SiO2 glasses and one Na2O–SiO2–P2O5 glass. The various Si/P↔Na/Ca contacts were probed by molecular dynamics (MD) simulations together with heteronuclear magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) experimentation utilizing (23)Na{(31)P} and (23)Na{(29)Si} REDOR, as well as (31)P{ (23)Na} and (29)Si{(23)Na} REAPDOR. We introduce an approach for quantifying the extent of Na(+)/Ca(2+) ordering around a given QP(n) or QSi(n) group, encoded by the preference factor 0⩽ PM ⩽ 1 conveying the relative weights of a random cation intermixing (PM = 0) and complete preference/ordering (PM = 1) for one of the species M, which represents either Na(+) or Ca(2+). The MD-derived preference factors reveal phosphate and silicate species surrounded by Na(+)/Ca(2+) ions intermixed nearly randomly (PM ≲ 0.15), except for the QSi(4) and QSi(1) groups, which manifest more significant cation ordering with preference for Na+ and Ca2+, respectively. The overall weak preferences are essentially independent of the Si and P contents of the glass, whereas PM primarily correlates with the total amount of network modifiers: as the latter is increased, the Na/Ca distribution around the {QP(0), QSi(1), QSi(2)} groups with preference for Ca2(+ )tend to randomize (i.e., PCa decreases), while the PNa-values grow slightly for the {QP(1), QSi(3), QSi(4)} species already preferring coordination of Na. The set of experimental preference factors {PCa} for the orthophosphate (QP(0)) groups extracted from (31)P{(23)Na} REAPDOR NMR-derived M2(P–Na) dipolar second moments agrees well with the MD-generated counterparts. Our results on the Na/Ca intermixing in soda-lime-silicate glasses are discussed in relation to previous reports, highlighting the dependence of the conclusion on the approach to data evaluation.
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Affiliation(s)
- Renny Mathew
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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16
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Shaharyar Y, Wein E, Kim JJ, Youngman RE, Muñoz F, Kim HW, Tilocca A, Goel A. Structure-solubility relationships in fluoride-containing phosphate based bioactive glasses. J Mater Chem B 2015; 3:9360-9373. [DOI: 10.1039/c5tb01494h] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structural role of fluoride on chemical dissolution behavior of bioactive phosphate glasses has been studied.
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Affiliation(s)
- Yaqoot Shaharyar
- Department of Materials Science and Engineering
- Rutgers
- The State University of New Jersey
- Piscataway
- USA
| | - Eric Wein
- Department of Materials Science and Engineering
- Rutgers
- The State University of New Jersey
- Piscataway
- USA
| | - Jung-Ju Kim
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Cheonan 330-714
- South Korea
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine
| | | | | | - Hae-Won Kim
- Institute of Tissue Regeneration Engineering (ITREN)
- Dankook University
- Cheonan 330-714
- South Korea
- Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine
| | - Antonio Tilocca
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
| | - Ashutosh Goel
- Department of Materials Science and Engineering
- Rutgers
- The State University of New Jersey
- Piscataway
- USA
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17
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Tilocca A. Atomic-scale models of early-stage alkali depletion and SiO2-rich gel formation in bioactive glasses. Phys Chem Chem Phys 2015; 17:2696-702. [DOI: 10.1039/c4cp04711g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular dynamics simulations of Na+/H+-exchanged 45S5 Bioglass® reveal the co-existence of bonded and non-bonded hydroxyls, suggesting a direct mechanism for forming a silica-rich gel structure upon the initial ion exchange.
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Affiliation(s)
- Antonio Tilocca
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
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18
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Yousefi AM, Hoque ME, Prasad RGSV, Uth N. Current strategies in multiphasic scaffold design for osteochondral tissue engineering: A review. J Biomed Mater Res A 2014; 103:2460-81. [PMID: 25345589 DOI: 10.1002/jbm.a.35356] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/04/2014] [Accepted: 10/12/2014] [Indexed: 12/23/2022]
Abstract
The repair of osteochondral defects requires a tissue engineering approach that aims at mimicking the physiological properties and structure of two different tissues (cartilage and bone) using specifically designed scaffold-cell constructs. Biphasic and triphasic approaches utilize two or three different architectures, materials, or composites to produce a multilayered construct. This article gives an overview of some of the current strategies in multiphasic/gradient-based scaffold architectures and compositions for tissue engineering of osteochondral defects. In addition, the application of finite element analysis (FEA) in scaffold design and simulation of in vitro and in vivo cell growth outcomes has been briefly covered. FEA-based approaches can potentially be coupled with computer-assisted fabrication systems for controlled deposition and additive manufacturing of the simulated patterns. Finally, a summary of the existing challenges associated with the repair of osteochondral defects as well as some recommendations for future directions have been brought up in the concluding section of this article.
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Affiliation(s)
- Azizeh-Mitra Yousefi
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, Ohio, 45056
| | - Md Enamul Hoque
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Malaysia Campus, Malaysia
| | - Rangabhatala G S V Prasad
- Biomedical and Pharmaceutical Technology Research Group, Nano Research for Advanced Materials, Bangalore, Karnataka, India
| | - Nicholas Uth
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, Ohio, 45056
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19
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Christie JK, Ainsworth RI, de Leeuw NH. Ab initio molecular dynamics simulations of structural changes associated with the incorporation of fluorine in bioactive phosphate glasses. Biomaterials 2014; 35:6164-71. [DOI: 10.1016/j.biomaterials.2014.04.032] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/10/2014] [Indexed: 11/16/2022]
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20
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Tilocca A. Cooling rate and size effects on the medium-range structure of multicomponent oxide glasses simulated by molecular dynamics. J Chem Phys 2014; 139:114501. [PMID: 24070291 DOI: 10.1063/1.4821150] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A set of molecular dynamics simulations were performed to investigate the effect of cooling rate and system size on the medium-range structure of melt-derived multicomponent silicate glasses, represented by the quaternary 45S5 Bioglass composition. Given the significant impact of the glass degradation on applications of these materials in biomedicine and nuclear waste disposal, bulk structural features which directly affect the glass dissolution process are of particular interest. Connectivity of the silicate matrix, ion clustering and nanosegregation, distribution of ring and chain structural patterns represent critical features in this context, which can be directly extracted from the models. A key issue is represented by the effect of the computational approach on the corresponding glass models, especially in light of recent indications questioning the suitability of conventional MD approaches (that is, involving melt-and-quench of systems containing ~10(3) atoms at cooling rates of 5-10 K/ps) when applied to model these glasses. The analysis presented here compares MD models obtained with conventional and nonconventional cooling rates and system sizes, highlighting the trend and range of convergence of specific structural features in the medium range. The present results show that time-consuming computational approaches involving much lower cooling rates and/or significantly larger system sizes are in most cases not necessary in order to obtain a reliable description of the medium-range structure of multicomponent glasses. We identify the convergence range for specific properties and use them to discuss models of several glass compositions for which a possible influence of cooling-rate or size effects had been previously hypothesized. The trends highlighted here represent an important reference to obtain reliable models of multicomponent glasses and extract converged medium-range structural features which affect the glass degradation and thus their application in different fields. In addition, as a first application of the present findings, the fully converged structure of the 45S5 glass was further analyzed to shed new light on several dissolution-related features whose interpretation has been rather controversial in the past.
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Affiliation(s)
- Antonio Tilocca
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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Mathew R, Stevensson B, Tilocca A, Edén M. Toward a rational design of bioactive glasses with optimal structural features: composition-structure correlations unveiled by solid-state NMR and MD simulations. J Phys Chem B 2014; 118:833-44. [PMID: 24364818 PMCID: PMC3905695 DOI: 10.1021/jp409652k] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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The
physiological responses of silicate-based bioactive glasses (BGs)
are known to depend critically on both the P content (nP) of the glass and its silicate network connectivity
(N̅BOSi). However, while the bioactivity generally
displays a nonmonotonic dependence on nP itself, recent work suggest that it is merely the net orthophosphate
content that directly links to the bioactivity. We exploit molecular
dynamics (MD) simulations combined with 31P and 29Si solid-state nuclear magnetic resonance (NMR) spectroscopy to explore
the quantitative relationships between N̅BOSi, nP, and the silicate and phosphate speciations in a series
of Na2O–CaO–SiO2–P2O5 glasses spanning 2.1 ≤ N̅BOSi ≤
2.9 and variable P2O5 contents up to 6.0 mol
%. The fractional population of the orthophosphate groups remains
independent of nP at a fixed N̅BOSi-value,
but is reduced slightly as N̅BOSi increases. Nevertheless, P
remains predominantly as readily released orthophosphate ions, whose
content may be altered essentially independently of the network connectivity,
thereby offering a route to optimize the glass bioactivity. We discuss
the observed composition-structure links in relation to known composition-bioactivity
correlations, and define how Na2O–CaO–SiO2–P2O5 compositions exhibiting
an optimal bioactivity can be designed by simultaneously altering
three key parameters: the silicate network connectivity, the (ortho)phosphate
content, and the nNa/nCa molar ratio.
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Affiliation(s)
- Renny Mathew
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University , SE-106 91, Stockholm, Sweden
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Berardo E, Corno M, Cormack AN, Ugliengo P, Tilocca A. Probing the fate of interstitial water in bulk bioactive glass by ab initio simulations. RSC Adv 2014. [DOI: 10.1039/c4ra05810k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mechanism and effects of the interaction of a water molecule with different sites found in the bulk of 45S5 bioactive glass have been investigated through ab initio simulations.
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Affiliation(s)
- Enrico Berardo
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
| | - Marta Corno
- Dipartimento di Chimica and NIS (Nanostructured Interfaces and Surfaces)
- Universitá di Torino
- 10125 Torino, Italy
| | | | - Piero Ugliengo
- Dipartimento di Chimica and NIS (Nanostructured Interfaces and Surfaces)
- Universitá di Torino
- 10125 Torino, Italy
| | - Antonio Tilocca
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
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23
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Tilocca A. Current challenges in atomistic simulations of glasses for biomedical applications. Phys Chem Chem Phys 2014; 16:3874-80. [DOI: 10.1039/c3cp54913e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Atomic-scale simulations of bioglasses are being used to tackle several challenging aspects, such as new structural markers of bioactivity, ion migration and nanosized samples.
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Affiliation(s)
- Antonio Tilocca
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
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24
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Ainsworth RI, Christie JK, de Leeuw NH. On the structure of biomedical silver-doped phosphate-based glasses from molecular dynamics simulations. Phys Chem Chem Phys 2014; 16:21135-43. [DOI: 10.1039/c4cp00574k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
First-principles and classical molecular dynamics simulations have been carried out on undoped and silver-doped phosphate-based glasses with 50 mol% P2O5, 0–20 mol% Ag2O, and varying amounts of Na2O and CaO.
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25
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Malik J, Tilocca A. Hydration Effects on the Structural and Vibrational Properties of Yttrium Aluminosilicate Glasses for in Situ Radiotherapy. J Phys Chem B 2013; 117:14518-28. [DOI: 10.1021/jp4073203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jahangir Malik
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Antonio Tilocca
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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26
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Abdollahi S, Ma ACC, Cerruti M. Surface transformations of Bioglass 45S5 during scaffold synthesis for bone tissue engineering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:1466-1474. [PMID: 23305513 DOI: 10.1021/la304647r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In physiological fluid, a layer of hydroxycarbonate apatite, similar to bone mineral, develops on the surface of Bioglass 45S5. Collagen from the surrounding tissue is adsorbed on this layer that attracts osteoblasts, and favors bone regrowth. Bioglass is therefore an osteoinductive material. Still, due to its brittleness, the glass alone cannot be used to heal large bone defects. To overcome this issue, Bioglass is used to form a composite scaffold with poly(D,L-lactide) (PDLLA), a biodegradable polymer. The goal of this work is to understand Bioglass reactivity throughout scaffold fabrication via a low-temperature route, the solvent casting and particulate leaching technique. Changes in Bioglass (especially its surface) are susceptible to occur both while in contact with the processing fluids and potentially through a reaction with the surrounding polymeric matrix. Here we analyzed the surface changes of three different Bioglass samples: (i) as-received, (ii) treated in solutions that parallel those used in scaffold fabrication, and (iii) extracted from the scaffolds. We showed that extracted, just like treated, Bioglass deviates from the as-received, but to a larger extent. X-ray photoelectron and infrared spectroscopy support the theory that Bioglass surface was modified not just through contact with the solutions in scaffold fabrication, but upon an interaction with the polymeric matrix. The polymer network slows down the Na(+)/H(+) exchange between Bioglass and water used to leach salt particles to create pores within the scaffold. Changes in surface properties affect the bioactivity of Bioglass and thus of the composite scaffolds, and are therefore critical to identify.
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Affiliation(s)
- Sara Abdollahi
- Biointerface Laboratory, Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, Quebec H3A 2B2, Canada
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27
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Di Tommaso D, Ainsworth RI, Tang E, de Leeuw NH. Modelling the structural evolution of ternary phosphate glasses from melts to solid amorphous materials. J Mater Chem B 2013; 1:5054-5066. [DOI: 10.1039/c3tb20662a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Goel A, Kapoor S, Tilocca A, Rajagopal RR, Ferreira JMF. Structural role of zinc in biodegradation of alkali-free bioactive glasses. J Mater Chem B 2013; 1:3073-3082. [DOI: 10.1039/c3tb20163e] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Smith JM, Martin RA, Cuello GJ, Newport RJ. Structural characterisation of hypoxia-mimicking bioactive glasses. J Mater Chem B 2013; 1:1296-1303. [DOI: 10.1039/c3tb00408b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Charpentier T, Menziani MC, Pedone A. Computational simulations of solid state NMR spectra: a new era in structure determination of oxide glasses. RSC Adv 2013. [DOI: 10.1039/c3ra40627j] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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31
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Christie JK, Tilocca A. Molecular Dynamics Simulations and Structural Descriptors of Radioisotope Glass Vectors for In Situ Radiotherapy. J Phys Chem B 2012; 116:12614-20. [DOI: 10.1021/jp304200f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Jamieson K. Christie
- Department of Chemistry and Thomas
Young Centre, University College London, 20 Gordon Street, London
WC1H 0AJ, U.K
| | - Antonio Tilocca
- Department of Chemistry and Thomas
Young Centre, University College London, 20 Gordon Street, London
WC1H 0AJ, U.K
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32
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Rosenholm JM, Mamaeva V, Sahlgren C, Lindén M. Nanoparticles in targeted cancer therapy: mesoporous silica nanoparticles entering preclinical development stage. Nanomedicine (Lond) 2012; 7:111-20. [PMID: 22191780 DOI: 10.2217/nnm.11.166] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Nanotechnology may help overcome persisting limitations of current cancer treatment and thus contribute to the creation of more effective, safer and more affordable therapies. While some nanotechnology-based drug delivery systems are already being marketed and others are in clinical trial, most still remain in the preclinical development stage. Mesoporous silica nanoparticles have been highlighted as an interesting drug delivery platform, due to their flexibility and high drug load potential. Although numerous reports demonstrate sophisticated drug delivery mechanisms in vitro, the therapeutic benefit of these systems for in vivo applications have been under continuous debate. This has been due to nontranslatable conditions used in the in vitro studies, as well as contradictory conclusions drawn from preclinical (in vivo) studies. However, recent studies have indicated that the encouraging cellular studies could in fact be repeated also in vivo. Here, we report on these recent advances regarding therapeutic efficacy, targeting and safety issues related to the application of mesoporous silica nanoparticles in cancer therapy.
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Affiliation(s)
- Jessica M Rosenholm
- Center for Functional Materials, Laboratory for Physical Chemistry, Department of Natural Sciences, Åbo Akademi University, Porthansgatan 3-5, FI-20500, Turku, Finland
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Cerruti M. Surface characterization of silicate bioceramics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:1281-1312. [PMID: 22349243 DOI: 10.1098/rsta.2011.0274] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The success of an implanted prosthetic material is determined by the early events occurring at the interface between the material and the body. These events depend on many surface properties, with the main ones including the surface's composition, porosity, roughness, topography, charge, functional groups and exposed area. This review will portray how our understanding of the surface reactivity of silicate bioceramics has emerged and evolved in the past four decades, owing to the adoption of many complementary surface characterization tools. The review is organized in sections dedicated to a specific surface property, each describing how the property influences the body's response to the material, and the tools that have been adopted to analyse it. The final section introduces the techniques that have yet to be applied extensively to silicate bioceramics, and the information that they could provide.
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Affiliation(s)
- Marta Cerruti
- Materials Engineering, McGill University, 3610 University Street, Montreal, Quebec, Canada H3A 2B2.
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Cormack AN, Tilocca A. Structure and biological activity of glasses and ceramics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:1271-1280. [PMID: 22349242 DOI: 10.1098/rsta.2011.0371] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Biomaterials for repairing and regenerating parts of the human body play a key role in contemporary medicine, and have an increasing impact in modern society. Given the importance of orthopaedic medicine (bone is the second most replaced organ after blood), bioactive glasses and ceramics represent a key reference to guide technological advances in this field. Their established role in current biomedical applications has already led many research groups worldwide to look into their structural properties, with a view to identifying the molecular basis of their biological activity. As the efforts directed towards this crucial and exciting direction continue to increase, it is now timely to review the situation, in order to guide future investigations on structure-bioactivity relationships. In this introductory article, the field is reviewed, to provide an appropriate context for the contributions to this Theme Issue.
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Affiliation(s)
- A N Cormack
- New York State College of Ceramics, Alfred University, Alfred, NY 14802, USA.
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35
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Martin RA, Moss RM, Lakhkar NJ, Knowles JC, Cuello GJ, Smith ME, Hanna JV, Newport RJ. Structural characterization of titanium-doped Bioglass using isotopic substitution neutron diffraction. Phys Chem Chem Phys 2012; 14:15807-15. [DOI: 10.1039/c2cp43032k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Martin RA, Twyman HL, Rees GJ, Smith JM, Barney ER, Smith ME, Hanna JV, Newport RJ. A structural investigation of the alkali metal site distribution within bioactive glass using neutron diffraction and multinuclear solid state NMR. Phys Chem Chem Phys 2012; 14:12105-13. [DOI: 10.1039/c2cp41725a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Christie JK, Tilocca A. Integrating biological activity into radioisotope vectors: molecular dynamics models of yttrium-doped bioactive glasses. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm31561k] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Christie JK, Malik J, Tilocca A. Bioactive glasses as potential radioisotope vectors for in situ cancer therapy: investigating the structural effects of yttrium. Phys Chem Chem Phys 2011; 13:17749-55. [PMID: 21887425 DOI: 10.1039/c1cp21764j] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The incorporation of yttrium in bioactive glasses (BGs) could lead to a new generation of radionuclide vectors for cancer therapy, with high biocompatibility, controlled biodegradability and the ability to enhance the growth of new healthy tissues after the treatment with radionuclides. It is essential to assess whether and to what extent yttrium incorporation affects the favourable properties of the BG matrix: ideally, one would like to combine the high surface reactivity typical of BGs with a slow release of radioactive yttrium. Molecular Dynamics simulations show that, compared to a BG composition with the same silica fraction, incorporation of yttrium results in two opposing effects on the glass durability: a more fragmented silicate network (leading to lower durability) and a stronger yttrium-mediated association between separate silicate fragments (leading to higher durability). The simulations also highlight a high site-selectivity and some clustering of yttrium cations, which are likely linked to the observed slow rate of yttrium released from related Y-BG compositions. Optimisation of yttrium BG compositions for radiotherapy applications thus depends on the delicate balance between these effects.
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Affiliation(s)
- Jamieson K Christie
- Department of Chemistry and Thomas Young Centre, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
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Christie JK, Pedone A, Menziani MC, Tilocca A. Fluorine Environment in Bioactive Glasses: ab Initio Molecular Dynamics Simulations. J Phys Chem B 2011; 115:2038-45. [DOI: 10.1021/jp110788h] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jamieson K. Christie
- Department of Chemistry and Thomas Young Centre, University College London, London WC1H 0AJ, U.K
| | | | | | - Antonio Tilocca
- Department of Chemistry and Thomas Young Centre, University College London, London WC1H 0AJ, U.K
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Tilocca A, Cormack AN. The initial stages of bioglass dissolution: a Car–Parrinello molecular-dynamics study of the glass–water interface. Proc Math Phys Eng Sci 2011. [DOI: 10.1098/rspa.2010.0519] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The initial dissolution stages following implantation of a biomaterial in a physiological environment are critical for its bioactive properties. Car–Parrinello molecular-dynamics (CPMD) simulations of the interface between the 45S5 bioglass surface and liquid water have been carried out to investigate these processes. The analysis of a 40 ps CPMD trajectory has highlighted the potential mechanism of Na
+
/H
+
exchange, leading to formation of surface silanols through water dissociation. Moreover, by comparing the properties of water layers arranged at different distances from the glass surface, we discuss the way in which the particular structure and composition of the bioglass surface affects the hydrogen-bond network and orientation of water in its close proximity.
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Affiliation(s)
- Antonio Tilocca
- Department of Chemistry and Thomas Young Centre for Theory and Simulations of Materials, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Alastair N. Cormack
- New York State College of Ceramics, Alfred University, Alfred, NY 14802, USA
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