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1.
Langmuir ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38635896

RESUMO

Amorphous silica particles (ASPs) have low biotoxicity and are used in foodstuffs; however, the adsorption states of proteins on their surfaces have not yet been clarified. If the adsorption states can be clarified and controlled, then a wide range of biological and medical applications can be expected. The conventional amorphous silica particles have the problem of protein adsorption due to the strong interaction with their dense silanol groups and denaturation. In this study, the surfaces of amorphous silica particles with a lower silanol group density were modified with a small amount of chlorine during the synthesis process to form a specific surface layer by adsorbing water molecules and ions in the biological fluid, thereby controlling the protein adsorption state. Specifically, the hydration state on the surface of the amorphous silica particles containing trace amounts of chlorine was evaluated, and the surface layer (especially the hydration state) for the adsorption of antibody proteins while maintaining their steric structures was evaluated and discussed. The results showed that the inclusion of trace amounts of chlorine increased the silanol groups and Si-Cl bonds in the topmost surface layer of the particles, thereby inducing the adsorption of ions and water molecules in the biological fluid. Then, it was found that a novel surface layer was formed by the effective adsorption of Na and phosphate ions, which would change the proportion of the components in the hydration layer. In particular, the proportion of the free water component increased by 21% with the doping of chlorine. Antibody proteins were effectively adsorbed on the particles doped with trace amounts of chlorine, and their steric adsorption states were evaluated. It was found that the proteins were clearly adsorbed and maintained the steric state of their secondary structure. In the immunoreactivity tests using streptavidin and biotin, biotin bound to the chlorine-doped particles showed efficient reactivity. In conclusion, this study is the first to discover the surface layer of the amorphous silica particles to maintain the steric structures of adsorbed proteins, which is expected to be used as a carrier particle for antibody test kits and immunochromatography.

2.
Langmuir ; 39(27): 9431-9438, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37386012

RESUMO

Hydroxyapatite (HA) particle, which is an inorganic component of biological hard tissues, is being applied as a bioceramic for biotechnology and medicine fields. However, early bone formation is difficult in the implantation of well-known stoichiometric HA into our body. To solve this problem, it is important to control the shapes and chemical compositions of the physicochemical properties of HA to be functionalized as the state similar to the biogenic bone. In this study, the physicochemical properties of the HA particles synthesized in the presence of tetraethoxysilane (TEOS) (SiHA particles) were evaluated and investigated. In particular, the surface layers of the SiHA particles were successfully controlled by adding silicate and carbonate ions in the synthetic, which would be involved in the bone formation process, and their elusive reaction behavior with phosphate-buffered saline (PBS) was also evaluated. The results showed that the ions in the SiHA particles increased with the increase in the added TEOS concentration, and the silica oligomer was also formed on the surfaces. The ions were present not only in the HA structures but also on the surface layers, indicating the formation of the non-apatitic layer containing the hydrated phosphate and calcium ions. The change in state of the particles with the immersion in PBS was evaluated, the carbonate ions eluted from the surface layer into PBS, and the free water component in the hydration layer increased with the immersion time in PBS. Therefore, we successfully synthesized the HA particles containing silicate and carbonate ions, suggesting the important state of the surface layer consisting of the characteristic non-apatitic layers. It was found that the ions in the surface layers can react with PBS and leach out, weakening the interaction of hydrated water molecules on the particle surfaces to increase the free water component in the surface layer.

3.
Biomimetics (Basel) ; 8(2)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37218770

RESUMO

In this review, the current status of the influence of added ions (i.e., SiO44-, CO32-, etc.) and surface states (i.e., hydrated and non-apatite layers) on the biocompatibility nature of hydroxyapatite (HA, Ca10(PO4)6(OH)2) is discussed. It is well known that HA is a type of calcium phosphate with high biocompatibility that is present in biological hard tissues such as bones and enamel. This biomedical material has been extensively studied due to its osteogenic properties. The chemical composition and crystalline structure of HA change depending on the synthetic method and the addition of other ions, thereby affecting the surface properties related to biocompatibility. This review illustrates the structural and surface properties of HA substituted with ions such as silicate, carbonate, and other elemental ions. The importance of the surface characteristics of HA and its components, the hydration layers, and the non-apatite layers for the effective control of biomedical function, as well as their relationship at the interface to improve biocompatibility, has been highlighted. Since the interfacial properties will affect protein adsorption and cell adhesion, the analysis of their properties may provide ideas for effective bone formation and regeneration mechanisms.

4.
ACS Appl Bio Mater ; 6(2): 473-482, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36648755

RESUMO

In the biomedical field, there has been a requirement for developing theranostic nanomaterials with higher biosafety, leading to both diagnosis and therapy. Methylene blue (MB+) is an organic dye with both photoluminescence (PL) and photosensitization abilities to generate singlet oxygen (1O2). However, MB+ easily loses its generation ability by hydrogen reduction in vivo or by forming aggregates. In this study, MB+ immobilized on biocompatible hydroxyapatite (HA) nanoparticles was applied for the bifunctions of efficient PL and photosensitization. The MB+-immobilized HA nanoparticles (MH) formed aggregates with sizes of 80-100 nm in phosphate buffer (PB). The generation amount and efficiency of 1O2 from the nanoparticles in PB seem to depend on the immobilized MB+ amount and the percentage of the monomer, respectively. Considering the larger immobilized amount and percentage of the MB+ monomer, it was found that there was MH with the lower generation amount and efficiency of 1O2 to exhibit the highest PL intensity. The photofunctional measurement of MB+ revealed the state of MB+ molecules on the HA surface, and it was suggested that the MB+ molecules immobilized on the MH surface would form more hydrogen bonds to change their excitation states. In the cellular experiments, the Hela cancer cells reacted with the nanoparticles and showed red-color PL, indicating cellular imaging. Furthermore, the adherent cell coverage decreased by 1O2 generation, indicating the importance of the immobilization amount of the MB+ monomer. Therefore, theranostic nanomaterials with biosafety were successfully synthesized to show two photofunctions, which provide both cellular imaging and photodynamic therapy by the nanohybrid system between HA and MB+.


Assuntos
Nanopartículas , Fotoquimioterapia , Humanos , Azul de Metileno/química , Medicina de Precisão , Durapatita , Nanopartículas/química , Fotoquimioterapia/métodos
5.
Phys Chem Chem Phys ; 25(5): 4025-4034, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36649129

RESUMO

A quartz crystal microbalance with dissipation (QCM-D) analysis was used to investigate fetal bovine serum (FBS) protein preadsorption on a hydroxyapatite (HAp) surface and the subsequent adhesion process of fibroblasts as compared with the case of oxidized poly(styrene) (PSox). The results showed that the preadsorption of FBS proteins on HAp promoted the subsequent initial cell adhesion ability. Moreover, the measured frequency (Δf) and dissipation shift (ΔD) curves, ΔD-Δf plots and viscoelastic analysis were used to study the initial cell adhesion process in real time. It was suggested that FBS-HAp showed sensitive changes in mass and viscoelasticity as compared with FBS-PSox, which realized the in situ reflection of the cell adhesion state, and the interfacial reactions between the cells and FBS-HAp surfaces such as dehydration and binding occurred to promote the initial cell adhesion and spreading. The viscoelastic analysis of the interface layer showed that the adhered cells on FBS-HAp could secrete some viscous substances such as extracellular matrix (ECM) proteins at the interfaces to provide good adhesion behaviors, and the Voigt-based viscoelastic model could clearly reveal the cellular interfacial viscoelasticity depending on the substrate surface. In addition, the morphology of cells was observed by confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM), and it was found that the pseudopodia were more uniformly stretched on FBS-HAp than on FBS-PSox. Furthermore, the state of the interfacial protein layer was analyzed by localized Fourier-transform infrared (FT-IR) spectroscopy and fluorescence microscopy (FLM), and it was indicated that the type of substrate affects the formation state of ECM proteins, resulting in changes in cell adhesion properties and morphology. The abundant formation of connective proteins (i.e., collagen type I) on FBS-HAp promoted subsequent pseudopodia formation and cell spreading. Therefore, the initial adhesion properties of fibroblasts on the FBS-HAp surface were systematically studied, which is of great importance for understanding the interfacial interaction between biomaterials and cells, and has great application value in biomedical fields.


Assuntos
Durapatita , Nanopartículas , Durapatita/química , Espectroscopia de Infravermelho com Transformada de Fourier , Proteínas , Adesão Celular , Fibroblastos
6.
J Mater Chem B ; 10(46): 9599-9606, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36128985

RESUMO

Hydroxyapatite (HA) and citric acid (Cit)-coordinated HA (Cit/HA) nanoparticle films with different nanospaces were used to examine the nanospacial effect on the protein adsorption behavior and initial osteoblast-like cell adhesion ability through the premise of the stability and ionic dissociation characteristics of the films in biological solution. In particular, the Cit/HA nanoparticle film with a nanospace of 4.2 nm could realize massive and stereoscopic adsorption of proteins due to its larger specific surface area and smaller nanospace as compared with the case of the HA nanoparticle film. It was also found that the α-helix and (ß-sheet + ß-turn) component ratios of the adsorbed fetal bovine serum proteins on the Cit/HA nanoparticle films increased as compared with the case of the HA nanoparticle film through the secondary structure analysis of the adsorbed proteins, which contributed to the good initial cell culture properties on the film surfaces. Therefore, we successfully realized the control of protein adsorption states using different nanospacial HA and Cit/HA nanoparticle films to achieve excellent initial cell culture properties, which would provide new insights into the creation of novel cell culture substrate surfaces in the regenerative medicine fields.


Assuntos
Durapatita , Nanopartículas , Durapatita/química , Adsorção , Adesão Celular , Ácido Cítrico , Soroalbumina Bovina/química
7.
Soft Matter ; 18(38): 7333-7340, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36112008

RESUMO

The mechanism of highly-oriented collagen (Col) fibril arrays on rubbed polyimide (PI) films was investigated in order to understand the interfacial Col-PI interactions. It was found that the orientation of the surface functional groups of the rubbed PI films was most effectively controlled and optimized by the rubbing conditions. In particular, nano-grooves with a width of 100-600 nm and a depth of 2-10 nm were formed on the rubbed PI films at a rubbing strength of 2.4 m, leading to the formation of the highest density of the Col fibril array. Moreover, highly-oriented Col fibrils were formed inside the nano-grooves by the formation of hydrogen bonds between the CO of the imide groups (@ rubbed PI films) and the N-H of the amino groups (@ ß-Sheets of Col molecules), resulting in the orientation of the Col molecules and subsequent assembly to the fibrils. Thus, the orientation and density of the fibril arrays on the rubbed PI films were successfully controlled by the interfacial interactions between the ß-Sheet component of Col and the nano-groove surfaces of the rubbed PI films. Therefore, the novel technology of this study will provide an effective method to fabricate the one-directional fibrous nanostructures and to understand how to control the orientation of biomolecules in vitro.


Assuntos
Nanoestruturas , Colágeno , Imidas , Nanoestruturas/química , Conformação Proteica em Folha beta , Propriedades de Superfície
8.
Molecules ; 27(18)2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36144659

RESUMO

Theranostics (bifunction of therapeutics and diagnostics) has attracted increasing attention due to its efficiency that can reduce the physical and financial burden on patients. One of the promising materials for theranostics is calcium phosphate (CP) and it is biocompatible and can be functionalized not only with drug molecules but also with rare earth ions to show photoluminescence that is necessary for the diagnostic purpose. Such the CP-based hybrids are formed in vivo by interacting between functional groups of organic molecules and inorganic ions. It is of great importance to elucidate the interaction of CP with the photofunctional species and the drug molecules to clarify the relationship between the existing state and function. Well-designed photofunctional CPs will contribute to biomedical fields as highly-functional ormultifunctional theranostic materials at the nanoscales. In this review, we describe the hybridization between CPs and heterogeneous species, mainly focusing on europium(III) ion and methylene blue molecule as the representative photofunctional species for theranostics applications.


Assuntos
Európio , Nanomedicina Teranóstica , Fosfatos de Cálcio , Humanos , Íons , Azul de Metileno , Medicina de Precisão
9.
Dalton Trans ; 51(33): 12442-12446, 2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-35946403

RESUMO

The phase transition of Ca-deficient hydroxyapatite (CDHA) with citric acid (Cit) coordination was investigated. Cit promoted the substitution of K+ ions into CDHA to generate the HA phase. The K+-doping increased the phase transition temperature of CDHA, providing the transition to ß- and α-tricalcium phosphates at higher temperatures. These results suggest controllable phase transition via Cit addition.


Assuntos
Ácido Cítrico , Durapatita , Fosfatos de Cálcio , Íons , Transição de Fase
10.
Micromachines (Basel) ; 13(8)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36014280

RESUMO

The highly-oriented structures in biological tissues play an important role in determining the functions of the tissues. In order to artificially fabricate oriented nanostructures similar to biological tissues, it is necessary to understand the oriented mechanism and invent the techniques for controlling the oriented structure of nanobiomaterials. In this review, the oriented structures in biological tissues were reviewed and the techniques for producing highly-oriented nanobiomaterials by imitating the oriented organic/inorganic nanocomposite mechanism of the biological tissues were summarized. In particular, we introduce a fabrication technology for the highly-oriented structure of nanobiomaterials on the surface of a rubbed polyimide film that has physicochemical anisotropy in order to further form the highly-oriented organic/inorganic nanocomposite structures based on interface interaction. This is an effective technology to fabricate one-directional nanobiomaterials by a biomimetic process, indicating the potential for wide application in the biomedical field.

11.
Biomimetics (Basel) ; 7(3)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35892367

RESUMO

The mineralization process of the osseous layer, which is highly calcified in vivo, was successfully imitated by the immersion process of the decalcified fish scales in simplified simulated body fluid (SSBF). An alkali treatment was used to modify the native collagen in the decalcified Tilapia fish scale. After the alkali treatment, the mineralization was facilitated in SSBF. The XRD patterns and SEM-EDS observation results demonstrated that the externally-mineralized layers by the immersion process were highly similar to the osseous layer containing lower-crystalline hydroxyapatite, suggesting that the simple biomimetic precipitation process was developed.

12.
Dalton Trans ; 51(25): 9572-9583, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35699123

RESUMO

Autogenous bone and metallic implant grafting has been used to repair and regenerate bone defects. However, there are still many unresolved problems. It is suggested that bioceramic nanoparticles should be developed and designed to promote effective bone regeneration. In addition, it is necessary to synthesize bioceramic nanoparticles that can support proteins related to bone repair and regeneration such as collagen and albumin. As the protein-interactive bioceramic, hydroxyapatite (HA) deserves to be mentioned and has several attractive properties that are useful in biomedical fields (e.g., biocompatibility, protein adsorption capacity and stability in the physiological environment). In order to prepare novel HA nanoparticles with high biocompatibility, it can be considered that human bones are mainly composed of HA and contain a small amount of silicate, and therefore, the design of coexistence of HA with silicate can be focused. Moreover, it is proposed that the state of the hydration layer on the nanoparticle surfaces can be controlled by introducing heteroelements and polymer chains, which have a great influence on the subsequent protein adsorption and cell adhesion. In this perspective, in order to develop novel bioceramic nanoparticles for the treatment of bone defect, the design of highly biocompatible HA nanoparticles and the control of the hydration layer and protein adsorption states on the surfaces were systematically discussed based on their surface modification techniques, which are very important for the proper understanding of the interface between cells and bioceramics, leading to the further application in biomedical fields.


Assuntos
Durapatita , Nanopartículas , Adsorção , Regeneração Óssea , Humanos , Silicatos
13.
Biomimetics (Basel) ; 7(2)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35466257

RESUMO

Biological hydroxyapatite (HA) contains the different minor ions which favour its bio-reactivity in vivo. In this study, the preparation of HA particles containing both silicate and carbonate ions under the presence of sodium silicate was investigated, and the physicochemical properties were evaluated according to the contents and states of silicate and carbonate ions. The increment in the silicate ion reduced the crystallinity and expanded the crystalline size along with a-axis. Solid-state 29Si-NMR spectra indicated the increase in the adsorption of oligomeric silicate species on the HA particle surfaces in addition to the substitution state of silicate ions, suggesting the occurrence of the surface coating of silicates on the surfaces. The possible states of carbonate and silicate ions at the HA surfaces will provide the bioactivity.

14.
Inorg Chem ; 61(12): 4865-4878, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35297609

RESUMO

We successfully synthesized methylene blue (MB+)-immobilized hydroxyapatite (HM) nanoparticles by changing the initial P/Ca molar ratio. The immobilized amount of MB+ increased with increasing the initial P/Ca molar ratio from 0.6 to 4.0, and the HM had an elliptical shape (long length, 21-24 nm; short length, 11-13 nm) irrespective of the initial P/Ca molar ratio. Upon increasing the initial P/Ca molar ratio, the number of carbonate ions on the HM surface decreased, which would be owing to the electrostatic repulsion by the surface phosphate ions (i.e., P-O-), the surface P-OH mainly dissociated to form P-O-, and the electrostatic interaction of P-O- with MB+ enhanced. The bonding of MB+ with surface P-OH and Ca2+ sites of hydroxyapatite would be hydrogen-bonding and Lewis acid-base interactions, respectively. The optimum synthesis condition for MB+ immobilization at the monomer state was found to be the initial P/Ca molar ratio of 2.0. Here, the existence percentage of the MB+ monomer and the molecular occupancy of the surface carbonate ion at the initial P/Ca molar ratio of 2.0 were higher than those at 4.0 with no significant difference in the immobilized amount of MB+, indicating that MB+ at the initial P/Ca molar ratio of 4.0 is more aggregated than that at 2.0. These results suggested that a part of carbonate ions has a role as a spacer to suppress MB+ aggregation. Accordingly, the interfacial interactions between the MB+ monomer and the hydroxyapatite surface were clarified, which can effectively be controlled by the initial P/Ca molar ratio. These findings will provide fundamental and useful knowledge for the design of calcium phosphate-organic nanohybrids. We believe that these particles will be the base materials to realize diagnostic and/or therapeutic functions through the molecular state control by optimizing the synthesis conditions.


Assuntos
Durapatita , Nanopartículas , Azul de Metileno
15.
Phys Chem Chem Phys ; 24(11): 6788-6802, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35244635

RESUMO

Silicate-containing hydroxyapatite (SiHA) particles were synthesized and functionalized with polyethylene glycol-silane (PEG-silane) for clarifying the effect of the bioceramic surface hydration layer states on the collagen (Col) fibrillation degree. Plate-like SiHA particles were obtained containing the SiO44- ion inside and/or outside the particles. PEG-silane was successfully functionalized on SiHA particles, and the hydration layer and Col adlayer states on the particles were precisely investigated for exemplifying the importance of the water molecular states at the interface. The ratio of free to intermediate water in the hydration layers of the particles decreased when containing silicate components, and it significantly increased with increasing PEG-silane molecular occupancy, where the asymmetric stretching vibration component ratio in the free water clearly increased. In a quartz crystal microbalance with dissipation (QCM-D) measurement, the frequency change (Δf) and the energy dissipation change (ΔD) values increased with Col adsorption on the particles for 32-34 min and then Δf slightly increased (or stopped increasing) and ΔD dramatically increased, indicating the effective water mobility and state changes with the Col fibrillation at the interface. The Col fibrillation degree evaluated by tan δ and the protein secondary structure of the adlayers clearly increased due to the PEG-silane functionalization, and the tendency was supported by the increase in the fibril density under SEM observation. Surprisingly, it was found that the fibrillation degree based on the protein secondary structure was significantly correlated with the asymmetric stretching vibration component ratio in the free water molecules of the hydration layer on the particles, suggesting the importance of the hydration layer states on bioceramics for controlling Col fibrillation.


Assuntos
Durapatita , Técnicas de Microbalança de Cristal de Quartzo , Adsorção , Colágeno , Durapatita/química , Silicatos
16.
J Mater Chem B ; 10(3): 396-405, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34935845

RESUMO

Hydroxyapatite (HA), as the main mineral component in hard tissues, has good biocompatibility. In particular, HA films are widely used as bioactive coatings for artificial bones and dental implants in biomedical fields. However, it is currently difficult to prepare a nanostructure-controlled HA film by a wet process for further applications. Herein, we report the synthesis of HA nanoparticles coordinated by citric acid (Cit/HA) based on the interactions between carboxylate and calcium ions to control the sizes and shapes of the hybrid nanoparticles, to improve their dispersibility in water and to eventually form uniform transparent films with nanospaces, and investigated the film formation mechanism. As compared with the well-known rod-like HA nanoparticles (size: 48 × 15 nm2), we successfully synthesized spherical and negatively charged Cit/HA nanoparticles (size: 25 × 23 nm2) to achieve highly transparent Cit/HA films using the spin-coating technique. The Cit/HA films had uniform and crack-free appearance. About the nanostructures, we found that the Cit/HA film surfaces had meso-scaled nanospaces with a diameter of 4.2 nm based on the regular arrangement of spherical nanoparticles, instead of the HA film with a nanospace diameter of 24.5 nm formed by non-uniform accumulation. Therefore, we successfully achieved the control of the nanospace sizes of the films with the nanoparticle arrangement and realized transparent nanoparticle film formation in a very simple way, which will provide more convenient bioceramic films for biomedical applications.


Assuntos
Ácido Cítrico/química , Complexos de Coordenação/química , Hidroxiapatitas/química , Nanopartículas/química , Animais , Cálcio/química , Linhagem Celular , Camundongos , Porosidade
17.
Inorg Chem ; 60(12): 8765-8776, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34080837

RESUMO

Functional nanomaterials are one of the potential carriers for drug delivery, whereas there are many prerequisites for this purpose. The carrier should be monodispersed, be fluorescent, and have a proper nanostructure to keep/release drug molecules to achieve controlled release, although preparing a nanomaterial which fulfills all the demands is still very challenging. In this paper, we show the preparation of monodispersed nanoporous amorphous titania submicron particles with fluorescent property. They adsorb a model drug molecule-ibuprofen-with their surface coverage up to 100%. Such a perfect loading does not decrease the fluorescent intensity because of any quenching effects but even maximize it. We also demonstrate the release behavior of IBU into simulated body fluid. Interestingly, the present carrier releases most of IBU in 6 h, whereas that modified with the polyethylene glycol moiety takes 48 h to finish releasing IBU, indicating its potential for controlled release applications.


Assuntos
Európio/química , Ibuprofeno/química , Luminescência , Compostos Organoplatínicos/síntese química , Titânio/química , Adsorção , Preparações de Ação Retardada , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Estrutura Molecular , Compostos Organoplatínicos/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
18.
Int J Mol Sci ; 22(11)2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34073002

RESUMO

For the development of next-generation protein-based biosensor surfaces, it is important to understand how functional proteins, such as fibrinogen (FBG), interact with polar substrate surfaces in order to prepare highly sensitive points of medical care diagnostics. FBG, which is a fibrous protein with an extracellular matrix, has both positively and negatively charged regions on its 3-dimensional surface, which makes interpreting how it effectively binds to polarized surfaces challenging. In this study, single-crystal LiNbO3 (LNO) substrates that have surface charges were used to investigate the adsorption of FBG protruding polar fragments on the positively and negatively charged LNO surfaces. We performed a combination of experiments and multi-scale molecular modeling to understand the binding of FBG in vacuum and water-solvated surfaces of LNO. XPS measurements showed that the FBG adsorption on LNO increased with increment in solution concentration on surfaces independent of charges. Multi-scale molecular modeling employing Quantum Mechanics, Monte Carlo, and Molecular Mechanics addressed the phenomenon of FBG fragment bonding on LNO surfaces. The binding simulation validated the experimental observation using zeta potential measurements which showed presence of solvated medium influenced the adsorption phenomenon due to the negative surface potential.


Assuntos
Fibrinogênio , Nióbio , Óxidos , Adsorção , Fibrinogênio/química , Fibrinogênio/metabolismo , Modelos Moleculares , Nióbio/química , Nióbio/metabolismo , Óxidos/química , Óxidos/metabolismo , Ligação Proteica , Propriedades de Superfície , Água/química
19.
J Mater Chem B ; 9(7): 1896-1907, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33533361

RESUMO

Transparent phosphorus-containing MPS (PMPS) films were synthesized by the introduction and reaction of phosphoric acid into the silica framework during the sol-gel reaction. We then investigated the hydration layer structures formed on the PMPS films and achieved the selective adsorption of fibronectin (Fn). In particular, the surface analyses indicated that the P atom was distributed at the outermost surfaces of the PMPS films. The PMPS films exhibited a high transparency (e.g., averaged transmittance value in the visible light region: 79%), and the haze value (0.14%) decreased with the increasing P/Si molar concentration. Solid-state 29Si-NMR and Fourier transform infrared spectroscopy (FT-IR) spectra indicated the formation of Si-O-P bonds, suggesting that the condensation reaction between the Si-O- and P-O- groups effectively occurs in the silica framework. The larger amount of P-O- and P[double bond, length as m-dash]O groups at the Si-O-P bonding site on the films affects the water molecular adsorption states (i.e., formation of the hydration layer), which was supported by the Brunauer-Emmett-Teller (BET) surface areas of N2 and water vapor, leading to enhancement of the hydrogen bondability of the PMPS films with the increased formation of Si-O-P bonds. The deconvolution results of the FT-IR spectra demonstrated that the ratio of free water to bonding water increased significantly with an increase in the formation of Si-O-P bonding, and the resulting O-H stretching vibration in the hydration layer became more asymmetric. It is suggested that the water molecules are irregularly hydrogen-bonded with the different functional groups of Si-O-, P-O- and P[double bond, length as m-dash]O. In the immersion experiment of the PMPS films in phosphate buffer, the resultant P/Si molar concentration of the PMPS film decreased upon increasing the immersion time and the mesostructures were preserved. The amount of Fn adsorption significantly increased as the O-H stretching vibration of the water molecules became more asymmetric, whereas the adsorption of fibrinogen was completely suppressed by the films. Therefore, we found that the addition of phosphoric acid in the MPS film synthesis significantly affects the hydration layer structures on the film surfaces to provide the possibility of selective protein adsorption.


Assuntos
Líquidos Corporais/química , Fósforo/química , Dióxido de Silício/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície , Água/química
20.
J Mater Chem B ; 9(8): 2054-2065, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33587739

RESUMO

The highly-oriented cylindrical mesoporous silica films were synthesized on the rubbing-treated polyimide by adjusting the molar ratio of the orientation-directing agent (Brij56) to the structure-directing agent (P123) as surfactants in the silica precursor solutions for guiding protein adsorption states. As a result, the diameter and the orientation degree of mesopores changed with the molar ratio of Brij56 to P123. The maximum orientation degree (93%) of cylindrical mesopores oriented in the direction perpendicular to the rubbing direction was observed when the molar ratio of Brij56 to P123 was 3. Then, the dissolution features in simulated body fluid and the protein adsorption properties of the oriented cylindrical mesoporous silica films were investigated. The silica skeletons were gradually dissolved from the upper film surfaces and subsequently, the mesopore structures were collapsed when the films were immersed for 90 min. Moreover, the protein adsorption amount and the ratio from the mono-component and two-component solutions on the films were higher than those on the unoriented cylindrical mesoporous silica films due to the formation of open-ended cylindrical mesopore shapes and sizes. In addition, the shapes of the proteins adsorbed on the films had anisotropy, which would be reflected by the cylindrical mesopore shapes generated by the dissolution of silica layers and subsequent exposure of inner mesopore surfaces. Therefore, the synthesized highly-oriented cylindrical mesoporous silica films were useful to adsorb mesoscale biomolecules such as proteins and can effectively guide their anisotropic adsorption shapes, and therefore have the potential to be used as surface-coating films of polyimide in biomedical fields.


Assuntos
Desenho de Fármacos , Proteínas/química , Dióxido de Silício/química , Adsorção , Cetomacrogol/química , Fenômenos Ópticos , Porosidade
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