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1.
Braz Oral Res ; 34: e004, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32022223

RESUMO

The aim of this study was to analyze the structural, morphological and mechanical properties of two different lithium disilicate glass-reinforced ceramics for CAD-CAM systems (IPS e.max CAD and Rosetta SM). Five methodologies were used for both ceramics: microstructure (n = 2) was analyzed using x-ray diffraction (XRD); morphological properties (n = 2) were analyzed by scanning electron microscopy (SEM), with and without hydrofluoric etching; porosity (n = 3) was assessed using 3D micro-computed tomography (micro-CT); flexural strength was measured (n =1 0) using the three-point bending test; and bond strength was determined with self-adhesive resin cement (n = 10), using a microshear bond test. After performing all the tests, the data were analyzed using t-Student test and two-way ANOVA. All the tests used a significance level of α = 0.05. High peak positions corresponding to standard lithium metasilicate and lithium disilicate with similar intensities were observed for both ceramics in the XRD analysis. Morphological analysis showed that the crystalline structure of the two ceramics studied showed no statistical difference after acid etching. Additionally, no significant differences were recorded in the number or size of the pores for the ceramics evaluated. Moreover, no differences in flexural strength were found for the ceramic materials tested, or in the bond strength to ceramic substrates for the resin cements. Based on the study results, no significant differences were found between the two CAD-CAM lithium disilicate glass-reinforced ceramics tested, since they presented similar crystalline structures with comparable intensities, and similar total porosity, flexural strength and bond strength.


Assuntos
Cerâmica/química , Projeto Auxiliado por Computador , Porcelana Dentária/química , Vidro/química , Análise de Variância , Colagem Dentária/métodos , Resistência à Flexão , Teste de Materiais , Microscopia Eletrônica de Varredura , Porosidade , Valores de Referência , Reprodutibilidade dos Testes , Cimentos de Resina/química , Resistência ao Cisalhamento , Propriedades de Superfície , Difração de Raios X
2.
Ecotoxicol Environ Saf ; 188: 109923, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31711779

RESUMO

In this work, ecotoxicological bioassays based on Lactuca sativa seeds and bioluminescent bacterium (Vibrio fischeri) have been carried out in order to quantify the toxicity of Norfloxacin (NOR) and sodium sulfate solutions, before and after treating them using electrochemical advanced oxidation. The effect of some process variables (anode material, reactor configuration and applied current) on the toxicity evolution of the treated solution has been studied. A NOR solution shows an EC50(5 days) of 336 mg L-1towards Lactuca sativa. This threshold NOR concentration decreases with sodium sulfate concentration, in solutions that contain simultaneously Norfloxacin and sodium sulfate. In every case considered in this work, the electrochemical advanced oxidation process increased the toxicity (towards both Lactuca sativa and Vibrio fischeri) of the solution. This toxicity increase is mainly due to the persulfate formation during the electrochemical treatment. From a final solution toxicity point of view, the best results were obtained using a BDD anode in a divided reactor applying the lowest current intensity.


Assuntos
Técnicas Eletroquímicas/métodos , Norfloxacino/toxicidade , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Aliivibrio fischeri/efeitos dos fármacos , Boro/química , Cerâmica/química , Diamante/química , Ecotoxicologia , Técnicas Eletroquímicas/instrumentação , Eletrodos , Alface/efeitos dos fármacos , Norfloxacino/análise , Oxirredução , Sulfatos/química , Poluentes Químicos da Água/análise
3.
Niger J Clin Pract ; 22(11): 1475-1482, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31719267

RESUMO

Objective: To compare the shear bond strength of resin cement to zirconia-based monolithic CAD-CAM materials subjected to different surface treatments. Methods: 2 brands of monolithic zirconia blocks (Vita YZ HT, Sirona inCoris TZI), yttrium-stabilized tetragonal zirconia (IPS e.max ZirCAD) and zirconia-reinforced lithium silicate ceramic (Vita Suprinity) were divided into six groups according to the surface treatment received: no treatment (control), HF acid etching, sandblasting, sandblasting + Er:YAG laser irradiation, Er:YAG laser irradiation and CoJet. Composite resin cylinders were bonded to blocks with self-adhesive resin cement (Theracem). Shear bond strength was evaluated after thermocyling. Failure modes were examined using SEM. Data was analyzed statistically by using 2-way ANOVA and post-hoc Tukey's test (P < 0,05). Results: The bond strength was significantly affected by the surface treatment and the type of CAD-CAM blocks (P < 0,001). Surface treatment with CoJet revealed significantly higher bond strength compared to sandblasting in Y-TZP and monolithic zirconia specimens. Conclusions: Monolithic zirconia blocks showed higher bond strength values compared to Y-TZP zirconia block in sandblasting and CoJet groups. HF acid etching is more effective than sandblasting and CoJet for Vita Suprinity.


Assuntos
Cerâmica/química , Resinas Compostas/química , Teste de Materiais/métodos , Cimentos de Resina/química , Resistência ao Cisalhamento , Zircônio , Projeto Auxiliado por Computador , Colagem Dentária , Humanos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Ítrio
4.
Environ Pollut ; 255(Pt 2): 113298, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610517

RESUMO

A biofilm reactor was designed with flat ceramic substrates to remove Co(II), Ni(II) and Zn(II) from industrial wastewater. The ceramics were made of clay and nano-rubber with high mechanical resistance. The surface of the ceramic substrate was modified with neutral fiber and nano-hydroxyapatite. A uniform and stable biofilm mass of 320 g with 2 mm of thickness was produced on the modified ceramic after 3 d. The micro-organisms were identified in the biofilm by polymerase chain reaction (PCR) method. Functional groups of biofilms were identified with a Fourier transform infrared spectrometer (FT-IR). Experiments were designed by central composite design (CCD) using the responsive surface method (RSM). The biosorption process was optimized at pH = 5.8, temperature = 22 °C, feed flux of heavy metal wastewater = 225 ml, substrate flow = 30 ml, and retention time = 7.825 h. The kinetic data was analyzed by pseudo first-order and pseudo second-order kinetic models. Isotherm models and thermodynamic parameters were applied to describe the biosorption equilibrium data of the metal ions on the biofilm-ceramic. The maximum biosorption efficiency and capacity of heavy metal ions were about 72% and 57.21 mg, respectively.


Assuntos
Biofilmes/crescimento & desenvolvimento , Reatores Biológicos/microbiologia , Cerâmica/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Metais Pesados/análise , Propriedades de Superfície
5.
Nanoscale ; 11(39): 18375-18381, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31573596

RESUMO

Octacalcium phosphate (OCP) is classified as a low-temperature phase of calcium phosphate (CaPs); it is a widely used ceramic material in biomedical applications. Interestingly, this study demonstrated the capacitive behavior of OCP as an electrode material in supercapacitors, alternatively named biosupercaps, for the first time in the literature. OCP powder was synthesized by solution precipitation at pH 5.5 at 60 °C in the presence of succinic acid. X-Ray diffraction (XRD) fully confirmed the OCP phase, with a crystallite size of around 40 nm, as calculated by the Scherrer equation. The FE-SEM micrographs of the OCP powder revealed plate-like morphology with a high surface area/thickness ratio. The surface widths of these layers ranged from about 2 to 100 microns, whereas the thickness of the layers was on the nanoscale (<100 nm). Raman spectroscopy was performed to confirm the microstructural formation of the OCP powder and electrodes according to the Raman spectra. Asymmetric and symmetric capacitors were prepared by various designs using OCP powder as a potential electrode material. The electrochemical performance of each biosupercap containing OCP was analyzed by a potentiostat in terms of current-voltage (CV) curves; each sample presented a typical pseudocapacitive behaviour. The electrochemical impedance spectra (EIS) of the OPC materials confirmed their significant capacitive performance, with up to 6 mA h g-1 specific capacity (SCp); this may be valuable for future medical electronics such as biocompatible energy storage and harvesting microdevices.


Assuntos
Fosfatos de Cálcio/química , Cerâmica/química , Capacitância Elétrica , Nanopartículas/química , Eletrodos
6.
Molecules ; 24(19)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575046

RESUMO

The preparation of ordered macroporous SiCN ceramics has attracted significant interest and is an attractive area for various applications, e.g., in the fields of catalysis, gas adsorption, or membranes. Non-oxidic ceramics, such as SiCN, own a great stability based on the covalent bonds between the containing elements, which leads to interesting properties concerning resistance and stability at high temperature. Their peculiar properties have become more and more important for a manifold of applications, like catalysis or separation processes, at high temperatures. Within this work, a feasible approach for the preparation of ordered porous materials by taking advantage of polymer-derived ceramics is presented. To gain access to free-standing films consisting of porous ceramic materials, the combination of monodisperse organic polymer-based colloids with diameters of 130 nm and 180 nm featuring a processable preceramic polymer is essential. For this purpose, the tailored design of hybrid organic/inorganic particles featuring anchoring sites for a preceramic polymer in the soft shell material is developed. Moreover, polymer-based core particles are used as sacrificial template for the generation of pores, while the preceramic shell polymer can be converted to the ceramic matrix after thermal treatment. Two different routes for the polymer particles, which can be obtained by emulsion polymerization, are followed for covalently linking the preceramic polysilazane Durazane1800 (Merck, Germany): (i) Free radical polymerization and (ii) atom transfer radical polymerization (ATRP) conditions. These hybrid hard core/soft shell particles can be processed via the so-called melt-shear organization for the one-step preparation of free-standing particle films. A major advantage of this technique is the absence of any solvent or dispersion medium, enabling the core particles to merge into ordered particle stacks based on the soft preceramic shell. Subsequent ceramization of the colloidal crystal films leads to core particle degradation and transformation into porous ceramics with ceramic yields of 18-54%.


Assuntos
Cerâmica/química , Polímeros/química , Hidrodinâmica , Polimerização , Porosidade , Termogravimetria
7.
Braz Oral Res ; 33: e095, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618283

RESUMO

This study evaluates the shear bond strength (SBS) of various resin cements to different ceramics. Composite resin cylinders of Z100 were fabricated and cemented to disks of feldspathic ceramic (Creation), leucite-reinforced feldspathic ceramic (Empress I), and densely sintered aluminum oxide ceramic (Procera AllCeram) using five resin cements: Panavia F (PAN), RelyX ARC (ARC), RelyX Unicem (RXU), RelyX Veneer, and Variolink II. SBS was measured after three days of water storage (baseline) and after artificial aging (180 days of water storage along with 12,000 thermal cycles). Failure mode of fractured specimens also was evaluated. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α=0.05). RXU showed 1) the lowest baseline median SBS to feldspathic ceramic, which was not statistically different from PAN; 2) the lowest median baseline SBS to leucite-reinforced feldspathic and densely sintered aluminum-oxide ceramics. All cements performed similarly after aging, except for ARC (median 0.0 MPa) and PAN (median 16.2 MPa) in the densely sintered aluminum-oxide ceramic group. Resin cements perform differently when bonded to different ceramic substrates. While all test resin cements worked similarly in the long-term to feldspathic and leucite-reinforced feldspathic ceramics, only the MDP-containing resin cement provided durable bonds to densely sintered aluminum-oxide ceramic.


Assuntos
Cerâmica/química , Colagem Dentária/métodos , Cimentos de Resina/química , Alumínio/química , Silicatos de Alumínio/química , Teste de Materiais , Compostos de Potássio/química , Valores de Referência , Reprodutibilidade dos Testes , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Propriedades de Superfície
8.
Braz Oral Res ; 33: e0088, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31531566

RESUMO

The main of the study was quantify the effect of two ceramics with two underlying resin cements on apparent fluorescence levels. Buccal surfaces of two bovine incisors were ground flat producing one enamel and one dentin substrate. The veneers were fabricated (0.5 and 1.0 mm thickness) using two ceramics (IPSe.max Press and IPSe.max Zirpress, Ivoclar Vivadent). Veneers were cemented using either light-cured (Variolink II, Ivoclar Vivadent) or self-adhesive dual (Rely X U200, 3M ESPE) cement. The layered Control group materials had no cement application. Semi-quantitative fluorescence image analysis (Matlabs software, Matworks) involved processing the images as captured under each daylight (DL, Gretagmacbeth) and ultraviolet illuminants (UVA, Sylvania) within a neutral-gray lightbox (Macbeth Spectral Light). Statistical analysis of the quantitative fluorescence values was performed using two-way ANOVA and Tukey's test (p < 0.05). The e.max Zirpress on the dentin substrate produced greater fluorescence (p < 0.05) when subjected to UV illumination and more fluorescence (p < 0.05) than e.max Press in both cement groups. Light-cured cement produced higher (p < 0.05) fluorescence than the dual-cement with e.max Press on enamel under UV illumination. The fluorescence for e.max Press on the dentin substrate was greater (p < 0.05) than for e.max Zirpress using dual self-adhesive cement subjected to daylight illumination. Thus, it is possible to conclude that the combination of ceramic and cement produce definite, significant effects on the apparent fluorescence, vital quality for restorative dentistry.


Assuntos
Cerâmica/química , Facetas Dentárias , Imagem Óptica/métodos , Cimentos de Resina/química , Animais , Bovinos , Esmalte Dentário/química , Esmalte Dentário/efeitos dos fármacos , Dentina/química , Dentina/efeitos dos fármacos , Luz , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Propriedades de Superfície
9.
Braz Oral Res ; 33: e041, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508723

RESUMO

The objective of this study was to evaluate the effect of the hydrofluoridric acid (HF) concentration and time of acid conditioning on bond strength of three glass ceramics to a resin cement. Thus, fifty blocks (10 mm x 5 mm x 2 mm) of each ceramic (LDCAD: IPS e.max CAD; LCAD: IPS Empress CAD and LDHP: IPS e.max Press) were made and embedded in acrylic resin. The surfaces were polished with sandpaper (#600, 800, 1000, and 1200 grits) and blocks were randomly divided into 15 groups (n = 10) according to the following factors: Concentration of HF (10% and 5%), conditioning time (20 s and 60 s) and ceramic (LDCAD, LDHP, and L). After conditioning, silane (Prosil / FGM) was applied and after 2 min, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block using a Teflon strip as matrix and light cured for 40 s (1,200 mW/cm2). Then, the samples were thermocycled (10,000 cycles, 5/55°C, 30s) and submitted to the shear bond test (50 KgF, 0.5 mm/min). The data (MPa) were analyzed with 3-way ANOVA and Tukey's test (5%). Failure analysis was performed using a stereomicroscope (20x) and a scanning electron microscope (SEM). ANOVA revealed that the "concentration" factor (p = 0.01) and the interaction "acid concentration X ceramic" (p = 0.009) had a significant effect, however, the "ceramic" (p = 0.897) and "conditioning time" (p = 0.260) factors did not influence the results. The LDHP10%60s (10.98 MPa)aA* group presented significantly higher bond strength than LDHP10%20s (6.57 MPa)bA, LCAD5%20s (6,90 ±3,5)aB and LDHP5%60s (5.66 ± 2,9MPa)aA* groups (Tukey). Failure analysis revealed that 100% of specimens had mixed failure. In conclusion, etching with 5% HF for 20 seconds is recommended for lithium disilicate and leucite-reinforced CAD/CAM ceramics. However, for pressed lithium disilicate ceramic, 10% HF for 60 s showed significantly higher bond strength to resin cement.


Assuntos
Ataque Ácido Dentário , Cerâmica/química , Colagem Dentária/métodos , Ácido Fluorídrico/administração & dosagem , Porcelana Dentária/química , Análise do Estresse Dentário , Ácido Fluorídrico/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Resistência ao Cisalhamento , Propriedades de Superfície , Fatores de Tempo
10.
Braz Oral Res ; 33: e042, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508725

RESUMO

This study evaluated the cytotoxicity and biocompatibility of a new bioceramic endodontic sealer (i.e., Sealer Plus BC) in comparison with those of MTA Fillapex and AH Plus. L929 fibroblasts were cultured and Alamar Blue was used to evaluate cell viability of diluted extracts (1:50, 1:100, and 1:200) from each sealer at 24 h. Polyethylene tubes that were filled with material or empty (as a control) were implanted in the subcutaneous tissue of rats. The rats were killed after 7 and 30 d (n = 8), and the tubes were removed for histological analysis. Parametric data was analyzed using a one-way ANOVA test, and nonparametric data was analyzed via the Kruskal-Wallis test followed by the Dunn test (p < 0.05). A reduction in cell viability was observed in the extracts that were more diluted for Sealer Plus BC when compared to that of Control and AH Plus (p < 0.05). However, the 1:50 dilution of the Sealer Plus BC was similar to that of the Control (p > 0.05). Conversely, more diluted extracts of MTA Fillapex (1:200) and AH Plus (1:100 and 1:200) were similar to the Control (p > 0.05). Histological analysis performed at 7 d did not indicate any significant difference between tissue response for all materials, and the fibrous capsule was thick (p > 0.05). At 30 d, Sealer Plus BC was similar to the Control (p > 0.05) and MTA Fillapex and AH Plus exhibited greater inflammation than the Control (p < 0.05). The fibrous capsule was thin for the Control and for most specimens of Sealer Plus BC and AH Plus. Thus, Sealer Plus BC is biocompatible when compared to MTA Fillapex and AH Plus, and it is less cytotoxic when less-diluted extracts are used.


Assuntos
Cimentos para Ossos/química , Hidróxido de Cálcio/química , Cerâmica/química , Materiais Restauradores do Canal Radicular/química , Compostos de Alumínio/química , Animais , Materiais Biocompatíveis , Cimentos para Ossos/farmacologia , Cimentos para Ossos/toxicidade , Compostos de Cálcio/química , Hidróxido de Cálcio/farmacologia , Hidróxido de Cálcio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas/efeitos dos fármacos , Combinação de Medicamentos , Resinas Epóxi/química , Fibroblastos/efeitos dos fármacos , Técnicas In Vitro , Inflamação , Masculino , Teste de Materiais , Óxidos/química , Ratos Wistar , Materiais Restauradores do Canal Radicular/toxicidade , Silicatos/química , Tela Subcutânea/patologia
11.
Braz Oral Res ; 33: e009, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508728

RESUMO

This study investigates the color correspondence of resin cements and try-in pastes, and the color stability of bonded lithium disilicate ceramic disks. Resin composite disks were fabricated (n = 36) to serve as the background for lithium disilicate disks prepared in two thicknesses (0.5 and 1.0 mm, n = 18 each). Two brands were used for try-in and cement procedures: Variolink Veneer and AllCem Veneer. For baseline, water was applied between the ceramic disks and their respective backgrounds to achieve the control group. This set was subjected to color measurement using an intraoral measurement device (T0). The try-in was inserted between background and ceramic, and this set was subjected to color measurement (T1). After adhesive procedures, the ceramic disk was placed under cement, and color measurement was performed with uncured cement (T2) and 24 h after light-curing (T3). Each set was immersed in distilled water and thermal-cycled, with color measurement being performed after 10,000 (T4) and 20,000 (T5) cycles. Color differences were calculated by CIELab (rEab) and CIEDE2000 (rE00). Data were analyzed by two-way ANOVA for repeated measurements and Tukey's test (α=5%). There was color correspondence of try-in and resin cement for the Variolink system, regardless of the ceramic thickness (p > 0.05). For the AllCem system, the thickness significantly influenced the color measurement (p < 0.001). The Variolink system also demonstrated color stability after 20,000 thermal cycles with rEab < 3.46 and rE00 < 2.25. It was concluded that the color correspondence between a try-in and its respective cement may vary according to resin cement composition.


Assuntos
Cor , Porcelana Dentária/química , Cimentos de Resina/química , Cerâmica/química , Facetas Dentárias , Técnicas In Vitro , Teste de Materiais , Pomadas/química
12.
Nanoscale ; 11(38): 17699-17708, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31545331

RESUMO

Biomaterial topography-based strategies are regarded as an effective way to regulate the osteoimmune environment which plays an indispensable role in the bone regeneration process. The rapid development of manufacture techniques makes it possible to investigate the cell-topography interactions by preparing various micro and nano-topographical surfaces on biomaterials. Still, it is a challenge to prepare well-defined micro/nano hierarchical structures of bioceramics due to the inherent brittleness of ceramic materials. Also, the correlation between osteoimmunomodulation initiated by micro/nano hierarchical topographies and the tissue regeneration outcomes is unclear. In this study, we prepared well-defined micro/nano hierarchical structures on hydroxyapatite (HA) bioceramics through the combination of the photolithography and hydrothermal techniques. Three different microscale circular patterns (4 µm, 12 µm and 36 µm) and nanotopographies (nanoneedle, nanosheet and nanorod) were fabricated by changing the size of the mask and the condition of the hydrothermal reaction. The macrophage responses on the nanoneedle structures with different micropatterns were investigated and the micro/nano hierarchical structures with appropriate pattern sizes could either promote or alleviate the macrophage polarization, which further affected the outcomes of the osteogenic differentiation of human bone marrow stromal cells (hBMSCs) and angiogenic activity of human umbilical vein endothelial cells (HUVECs). Our study demonstrated that osteoimmunomodulation could be manipulated via tuning the micro/nano hierarchical structures, which could lead to a new strategy for the development of bone biomaterials with favorable osteoimmunomodulatory properties.


Assuntos
Células da Medula Óssea/metabolismo , Cerâmica , Durapatita , Células Endoteliais da Veia Umbilical Humana/metabolismo , Nanopartículas/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Animais , Células da Medula Óssea/citologia , Cerâmica/química , Cerâmica/farmacologia , Durapatita/química , Durapatita/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Camundongos , Células RAW 264.7 , Células Estromais/citologia , Células Estromais/metabolismo
13.
Mater Sci Eng C Mater Biol Appl ; 105: 109912, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546348

RESUMO

In this study, a simple and facile strategy was developed for the synthesis of novel hydroxyapatite (HA)/nanostructured monticellite ceramic composites by mechanical method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS) were used to peruse the phase structure, and morphology of soaked ceramic composites in simulated body fluid (SBF). The in vitro bioactivity of HA-based ceramic composites with nanostructured monticellite ranging from 0 to 50 wt% was evaluated via investigating the formation ability of bone-like calcium phosphates in SBF and the effect of obtained extracts from composites dissolution on osteoblast-like G-292 cell line. Moreover, In vitro cytocompatibility of the HA/monticellite ceramic composites was investigated by MTT, cell growth & adhesion and alkaline phosphatase (ALP) activity assays, and quantitative real-time PCR analysis. The results showed that HA/nanostructured monticellite ceramic composites could induce apatite formation in SBF. The cell proliferation and growth exposed to ceramic composites extracts were significantly stimulated and promoted at a certain concentration range compared to control for various time periods of cell culture. The optimized composite extract enhanced considerably gene expression of G-292 type X collagen (COLX) at different days. Also, G-292 cells were spread and adhered well on the ceramic composite disc. Furthermore, ALP activity of G-292 cells exposed to ceramic composites extracts was dramatically enhanced in comparison with pure HA extract (as control) at different concentrations for various time periods of cell culture. The results suggest that the optimized HA/nanostructured monticellite composite is promising biomaterial for clinical applications such as orthopedic and dentistry.


Assuntos
Materiais Biocompatíveis/síntese química , Tecnologia Biomédica/métodos , Durapatita/síntese química , Nanoestruturas/química , Ácido Silícico/síntese química , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/química , Adesão Celular , Linhagem Celular , Proliferação de Células , Cerâmica/química , Colágeno Tipo X/metabolismo , Corrosão , Durapatita/química , Humanos , Osteoblastos/citologia , Osteogênese , Tamanho da Partícula , Ácido Silícico/química , Difração de Raios X
14.
Mater Sci Eng C Mater Biol Appl ; 105: 110009, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546356

RESUMO

In the present study, a two-step sintering (TSS) method has been used to improve the mechanical properties, biocompatibility, drug release, and osteogenesis abilities of hardystonite (HT) ceramic scaffolds for tissue engineering and drug delivery applications. The average particle size of HT scaffold is kept lower than 80 nm and is reached higher than 130 nm by using two-step and conventional sintering methods, respectively. The compressive strengths of the prepared nanocrystalline HT scaffolds were found to be significantly higher than those of the micro-structure HT and currently available hydroxyapatite scaffolds. A comparative analysis of cell viability and live/dead staining of human mesenchymal stem cells (hMSCs) in nano- and micro-structured HT scaffolds and their drug release potentiation was carried out. The results showed that the nano-structured HT scaffolds have higher cell viability, biocompatibility and longer-term doxorubicin (DOX) release potential than the micro-structured ones. The results of quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) analyses showed that the expression of adhesion and differentiation supporting genes were significantly higher in nano-structured HT scaffolds as compared to the micro-structured ones. The results of qRT-PCR also showed that the mRNA expression level of ERK1/2 and P38 MAPK from hMSCs were significantly higher in nano-structured HT scaffolds than the micro-structured ones. These results potentially open new aspects for using nano-structured scaffolds in bone tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Cerâmica/química , Temperatura Alta , Engenharia Tecidual/métodos , Tecidos Suporte/química , Biomarcadores/metabolismo , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Força Compressiva , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanoestruturas/química , Osteocalcina/metabolismo , Osteonectina/metabolismo , Tamanho da Partícula , Silicatos/química , Fatores de Tempo , Difração de Raios X
15.
Mater Sci Eng C Mater Biol Appl ; 105: 110036, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546358

RESUMO

Rapid vascularization and long-term antibacterial property are desirable characteristics of the next-generation implants in orbital reconstruction. In this study, the new diopside-based orbital implants were developed by direct ink writing of diopside (CaMgSi2O6; DIO) and low-melt bioactive glass (BG)-assisted sintering approaches. The mechanical tests showed that the addition 5% or 10% BG could readily enhance the compressive strength of the DIO porous bioceramics after sintering at 1150 °C. The Tris buffer immersion test in vitro indicated that the porous bioceramics exhibited appreciable mechanical stability and very limited mass loss (<3.5%) after 8 weeks. The DIO/10BG porous bioceramic sintered at 1150 °C or 1250 °C could promote appreciable angiogenesis response at the early stage (2-6 weeks) of implantation in the rabbit panniculus carnosus muscle models in vivo. It is interesting that the steam autoclaved bioceramics exhibited outstanding contact-active inhibition against Staphylococcus aureus and Pseudomonas aeruginosa, but as-sintered bioceramics showed no antibacterial effect. It is reasonable to consider that our strategy paves the way toward a simple and effective approach to fabricate the multifunctional tailormade implants for orbital implantation, thus accelerating the clinical translation of biomaterials research.


Assuntos
Antibacterianos/farmacologia , Cerâmica/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Implantes Orbitários , Ácido Silícico/farmacologia , Animais , Cerâmica/química , Masculino , Testes de Sensibilidade Microbiana , Porosidade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
16.
Mater Sci Eng C Mater Biol Appl ; 105: 110071, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546377

RESUMO

In the current study, in vitro analysis of the osteogenic potential of different scaffolds based on strontium-substituted ß-TCP (Sr-TCP) and bioactive glass (BG) ceramics was conducted using rabbit bone marrow-derived mesenchymal stem cells (rBMSCs) and the osteogenic ability of the prepared Sr-TCP and BG scaffold was evaluated through alkaline phosphatase activity, mineral deposition by Alizarin red staining, and osteoblastic gene expression experiments. The obtained in vitro results revealed that among experimental Sr-TCP/BG nanocomposite scaffold samples with the composition of Sr-TCP/BG: 100/0, 50/50, 75/25, and 25/75, the 50Sr-TCP/50BG sample presented better osteoinductive properties. Therefore, the optimized 50Sr-TCP/50BG nanocomposite scaffold was chosen for further in vivo experiments. In vivo implantation of 50Sr-TCP/50BG scaffold and hydroxyapatite (HA)/TCP granules in a rabbit calvarial defect model showed slow degradation of 50Sr-TCP/50BG scaffold and high resorption rate of HA/TCP granules at 5 months' post-surgery. However, the 50Sr-TCP/50BG scaffolds loaded by mesenchymal stem cells (MSCs) were mainly replaced with new bone even at 2 months post-implantation. Based on the obtained engineering and biological results, 50Sr-TCP/50BG nanocomposite scaffold containing MSCs could be considered as a promising alternative substitute even for load-bearing bone tissue engineering applications.


Assuntos
Células da Medula Óssea/metabolismo , Fosfatos de Cálcio/química , Células Imobilizadas , Cerâmica/química , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Nanocompostos/química , Estrôncio/química , Tecidos Suporte/química , Animais , Células da Medula Óssea/patologia , Células Imobilizadas/metabolismo , Células Imobilizadas/patologia , Células Imobilizadas/transplante , Células-Tronco Mesenquimais/patologia , Porosidade , Coelhos
17.
Mater Sci Eng C Mater Biol Appl ; 105: 110053, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546420

RESUMO

The surface chemistry of silicon nitride plays an important role in stimulating osteoblasts to proliferate and produce bone tissue with improved efficiency. This property, which is advantageous in spinal fusion surgery has a chemical origin and is a direct consequence of the cleavage of covalent SN bonds in an aqueous environment. Building upon a wealth of published research on the stimulation of osteoblastic activity by silicon, the aim of this paper is to explore the role of nitrogen and, more specifically, the N/Si atomic ratio on the osteogenic response of Si3N4. The surface stoichiometry of Si3N4 was gradually altered toward a silicon-rich composition by systematically treating the Si3N4 surface with a high-power pulsed laser in an Ar gas atmosphere (i.e., operated at different pulse times, spot sizes, and voltages). Different analytical probes were used to characterize the surface including X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDS). Osteoconductivity was tested in vitro using SaOS-2 osteosarcoma cells, and samples with different surface stoichiometry were compared for their osteogenic response. These experiments clearly indicated a fundamental role for nitrogen off-stoichiometry in osteogenesis, and showed that both cell proliferation and growth of bone tissue diminished with decreasing nitrogen content.


Assuntos
Cerâmica , Teste de Materiais , Nitrogênio , Osteogênese/efeitos dos fármacos , Compostos de Silício , Linhagem Celular Tumoral , Cerâmica/química , Cerâmica/farmacologia , Humanos , Nitrogênio/química , Nitrogênio/farmacologia , Compostos de Silício/química , Compostos de Silício/farmacologia
18.
Mater Sci Eng C Mater Biol Appl ; 105: 110083, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546466

RESUMO

Cutaneous wounds, especially chronic wounds, remain clinical challenges, and this is partially due to the complex healing process composed of four overlapping but distinct stages including hemostasis, inflammation, proliferation and remodeling. Therefore, wound dressings with spatially designed structures which can temporally regulate certain bioactive components to function at specific healing stages might be able to accelerate the healing process. In this study, nanobioglass incorporated chitosan-PVA (polyvinyl alcohol) trilayer nanofibrous membrane (nBG-TFM) was fabricated via sequential electrospinning. This membrane exhibited excellent biocompatibility, antibacterial activity and regeneration promotion effect. Furthermore, spatially designed structure optimized functions of each component and provided more suitable microenvironment as compared with uniform membrane. Rat full-thickness skin defects model and mice diabetic chronic wound model showed that nBG-TFM could achieve significantly accelerated and enhanced healing, in terms of complete re-epithelialization, improved collagen alignment and formation of skin appendages. It was revealed that nBG-TFM functioned through upregulating growth factors including VEGF and TGF-ß. Meanwhile inflammatory cytokines such as TNF-α and IL-1ß were downregulated. The technology presented in this study shed new light on designing functional wound dressings which can promote healing of chronic wounds.


Assuntos
Bandagens , Cerâmica , Quitosana , Membranas Artificiais , Nanofibras , Álcool de Polivinil , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões , Animais , Linhagem Celular , Cerâmica/química , Cerâmica/farmacologia , Quitosana/química , Quitosana/farmacologia , Doença Crônica , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Complicações do Diabetes/terapia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Masculino , Camundongos , Nanofibras/química , Nanofibras/uso terapêutico , Álcool de Polivinil/química , Álcool de Polivinil/farmacologia , Ratos , Ratos Sprague-Dawley , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologia , Ferimentos e Lesões/terapia
19.
Biomed Mater Eng ; 30(4): 419-426, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31498119

RESUMO

BACKGROUND: The chemical properties of the oral environment have an appreciable influence on the in vivo degradation of CAD/CAM materials. OBJECTIVE: The aim of the present study was to investigate the effect of organic acids, heptane and ethanol (the food-simulating liquids) on CAD/CAM restorative materials. METHODS: Four CAD/CAM materials were selected: (1) 3M ESPE LAVA Ultimate, (2) VITA Enamic, (3) IPS e.max CAD, (4) VITA Suprinity. Seven different samples were fabricated in 15 × 4 × 1.2 mm dimensions from each material (n = 7, N = 140). The materials were conditioned for 7 days at 37 °C as follows: artificial saliva, 75% ethanol, heptane, 0.02 N citric acid, 0.02 N lactic acid in aqueous solution and were tested to obtain flexural strength, surface micro-hardness and wear characteristics. After conditioning, the flexural strength values were assessed using a universal testing machine (1 mm/min crosshead speed) and the fractured samples were used for determination of Vickers hardness values using a digital micro-hardness tester (100 g/10 s) and determination of wear using a chewing simulator. Two factor analysis of variance with interaction model and Tukey's post hoc test were used for statistical analysis. RESULTS: The highest mechanical property values were found for IPS e.max and VITA Suprinity and the lowest values were found for LAVA Ultimate. Organic acids negatively affected the mechanical properties of e.max CAD and Suprinity. Ethanol and heptane were more effective on LAVA Ultimate and Enamic. There were significant differences among groups (p < 0.05). CONCLUSION: The mechanical properties of CAD/CAM restorative materials are influenced by food-simulating liquids.


Assuntos
Cerâmica/química , Materiais Dentários/química , Materiais Biocompatíveis/química , Ácido Cítrico/química , Dureza , Humanos , Ácido Láctico/química , Teste de Materiais , Saliva/química , Estresse Mecânico , Propriedades de Superfície
20.
Mater Sci Eng C Mater Biol Appl ; 104: 109842, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500042

RESUMO

Hydroxyapatite (HA) ceramics are well known for their biocompatibility, bioactivity, and osteoconductive nature. However, limited hierarchical structure and lack of ease in modularity hinder the widespread application of conventional HA ceramics. By using three-dimensional printing (3DP) techniques with multiple materials, including HA, complex biological and mechanical architecture of natural organisms can be achieved through biomimetics. In this study, we designed an osteoid, biomimetic, hierarchical, porous HA ceramic 3D printed scaffold (3DPs). Further incorporation of a covalent, modular, controlled release system (CMR), based on Watson-Crick's complementary oligonucleotides, and was added to carry a bone morphogenetic protein-2 (BMP2) peptide. The choice of a HA biomimetic scaffold housing BMP2 protein fragments was selected to successfully promote osteogenesis both in vitro and in vivo. Scanning electron microscopy, micro-computed tomography analysis and computer fluid dynamics simulations of the 3DPs showed a uniform biomimetic hierarchical structure and an effective interior permeability. Active molecules were found bound with high stability and modular to the scaffold surface via the CMR system. After 7 days of incubation under physiological conditions, approximately 90% of active factors remained bound. Compared to control groups, the 3DPs-CMR-BMP2 group significantly enhanced cell proliferation and adhesion. Moreover, the 3DPs-CMR-BMP2 group exhibited more extensive and sustained osteogenic effects through upregulated expression of osteogenic factors and enhanced calcium deposition, as compared to study and control groups. Furthermore, ectopic osteogenesis and a critical calvarial defect model confirmed that the 3DPs-CMR-BMP2 group significantly promoted in vivo bone healing versus control. Thus, our results showed that biomimetic hierarchical 3DPs with a CMR system successfully promote cell proliferation, adhesion, differentiation and osteogenesis, on a continuous cycle. The biomimetic hierarchical 3DPs with a CMR system offers a promising multi-functional, bone substitute material for treatment of patients with bone defects.


Assuntos
Biomimética , Sistemas de Liberação de Medicamentos , Osteogênese , Impressão Tridimensional , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Cerâmica/química , Durapatita/química , Fluorescência , Regulação da Expressão Gênica , Hidrodinâmica , Masculino , Minerais/metabolismo , Oligonucleotídeos/química , Osteogênese/genética , Permeabilidade , Porosidade , Ratos Sprague-Dawley , Microtomografia por Raio-X
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