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1.
Braz Oral Res ; 33: e079, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31531565

RESUMO

Cell therapy associated with guided bone regeneration (GBR) can be used to treat bone defects under challenging conditions such as osteoporosis. This study aimed to evaluate the effect of mesenchymal stem cells (MSCs) in combination with a poly(vinylidene-trifluoroethylene)/barium titanate (PVDF-TrFE/BT) membrane on bone repair in osteoporotic rats. Osteoporosis was induced in female rats by bilateral removal of the ovaries (OVX) or sham surgery (SHAM), and the osteoporotic condition was characterized after 5 months by microtomographic and morphometric analyses. Calvarial defects were created in osteoporotic rats that immediately received the PVDF-TrFE/BT membrane. After 2 weeks, bone marrow-derived MSCs from healthy rats, characterized by the expression of surface markers using flow cytometry, or phosphate-buffered saline (PBS) (Control) were injected into the defects and bone formation was evaluated 4 weeks post-injection by microtomographic, morphometric, and histological analyses. A reduction in the amount of bone tissue in the femurs of OVX compared with SHAM rats confirmed the osteoporotic condition of the experimental model. More bone formation was observed when the defects were injected with MSCs compared to that with PBS. The modification that we are proposing in this study for the classical GBR approach where cells are locally injected after a membrane implantation may be a promising therapeutic strategy to increase bone formation under osteoporotic condition.


Assuntos
Compostos de Bário/farmacologia , Regeneração Tecidual Guiada/métodos , Células-Tronco Mesenquimais/fisiologia , Osteogênese/efeitos dos fármacos , Osteoporose/terapia , Polivinil/farmacologia , Titânio/farmacologia , Animais , Compostos de Bário/química , Densidade Óssea , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Feminino , Citometria de Fluxo , Imageamento Tridimensional , Células-Tronco Mesenquimais/química , Osteogênese/fisiologia , Osteoporose/fisiopatologia , Ovariectomia , Polivinil/química , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Titânio/química , Resultado do Tratamento
2.
Environ Pollut ; 255(Pt 1): 113182, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541840

RESUMO

Methylene blue (MB) is a dye pollutant commonly present in textile wastewater. We investigate and critically evaluate the applicability of BaTiO3/GO composite for photodegradation of MB in synthetic wastewater under UV-vis irradiation. To enhance its performance, the BaTiO3/GO composite is varied based on the BaTiO3 weight. To compare and evaluate any changes in their morphologies and crystalline structures before and after treatment, BET (Brunauer-Emmett-Teller), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) tests are conducted, while the effects of reaction time, pH, dose of photocatalyst and initial MB concentration on its photodegradation by the composite are also investigated under identical conditions. The degradation pathways and removal mechanisms of MB by the BaTiO3/GO are elaborated. It is evident from this study that the BaTiO3/GO composite is promising for MB photodegradation through ·OH. Under optimized conditions (0.5 g/L of dose, pH 9.0, and 5 mg/L of MB concentration), the composite with 1:2 dose ratio of BaTiO3/GO has the highest MB degradation rate (95%) after 3 h of UV vis irradiation. However, its treated effluents still could not comply with the discharge standard limit of less than 0.2 mg/L imposed by national environmental legislation. This suggests that additional biological treatments are still required to deal with the remaining oxidation by-products of MB, still present in the wastewater samples such as 3,7-bis (dimethyl-amino)-10H-phenothiazine 5-oxide.


Assuntos
Compostos de Bário/química , Grafite/química , Azul de Metileno/química , Titânio/química , Águas Residuárias/química , Purificação da Água/métodos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Compostos Orgânicos , Fotólise , Espectroscopia de Infravermelho com Transformada de Fourier , Raios Ultravioleta , Difração de Raios X
3.
Analyst ; 144(19): 5717-5723, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31482883

RESUMO

An innovative visible light-driven photoelectrochemical (PEC) immunosensing system was reasonably established for the sensitive detection of prostate-specific antigen (PSA) by using perovskite metal oxide@gold nanoparticle heterostructures (BaTiO3/Au) as the photoactive materials. When plasmonic Au nanoparticles were directly decorated on BaTiO3, a several times surface plasmon resonance (SPR) enhancement of photocurrent density was induced via the injection of hot electrons from visible light-excited Au nanoparticles into the conduction band of BaTiO3, and the combination of BaTiO3 and Au nanoparticles was employed as a promising platform for developing a photoelectrochemical bioanalysis. As a proof of concept, PSA had been detected by the BaTiO3/Au nanocomposite-based PEC sensor. To design such an immunoassay protocol, a monoclonal anti-PSA capture antibody (cAb)-coated microplate and glucose oxidase/polyclonal anti-PSA detection antibody-modified gold nanoparticles (GOx-Au NP-dAb) were used as the immunoreaction platform and signal probe, respectively. Upon the addition of target PSA, a sandwiched immunocomplex was formed accompanying the immuno-recognition between the antigen and antibody, and then the carried GOx could oxidize glucose to produce H2O2. The photocurrent of the BaTiO3/Au nanocomposite-functionalized electrode amplified with increasing H2O2 concentration since H2O2 is considered as a good hole scavenger. On the basis of the above-mentioned mechanisms and the optimized conditions, the assembled PEC immunosensor was linear with the logarithm of the PSA concentration in the range of 0.01-40 ng mL-1 with a detection limit of 4.2 pg mL-1. It afforded rapid response, good precision, and high stability and specificity, implying its great promise in photoelectrochemical immunoassays. More generally, this system sets up an ideal PEC immunosensing system based on the BaTiO3/Au nanocomposites and represents an innovative and low-cost "signal-on" assay scheme for the practical quantitative screening of low-abundance proteins.


Assuntos
Compostos de Bário/química , Ouro/química , Calicreínas/sangue , Nanopartículas Metálicas/química , Antígeno Prostático Específico/sangue , Titânio/química , Anticorpos Monoclonais/imunologia , Compostos de Bário/efeitos da radiação , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Glucose/análise , Glucose Oxidase/química , Ouro/efeitos da radiação , Humanos , Peróxido de Hidrogênio/química , Imunoensaio/métodos , Calicreínas/imunologia , Luz , Limite de Detecção , Nanopartículas Metálicas/efeitos da radiação , Nanocompostos/química , Nanocompostos/efeitos da radiação , Processos Fotoquímicos , Estudo de Prova de Conceito , Antígeno Prostático Específico/imunologia , Ressonância de Plasmônio de Superfície/métodos , Titânio/efeitos da radiação
4.
Biomed Mater ; 14(3): 035011, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30802890

RESUMO

Nanomaterials can mimic properties of extracellular matrix molecules, promising great potential for scaffold composition in tissue engineering. In the present study, we investigated whether barium titanate nanoparticles (BT NP) combined with alginate polymer would provide a new cytocompatible three-dimensional (3D) scaffold to induce osteogenic stem cell differentiation. In vitro cytocompatibility and osteogenic differentiation potential were investigated using human mesenchymal stem cells (MSC). Firstly, we studied the cell viability and oxidative stress by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) thiazolyl blue tetrazolium bromide (MTT) and superoxide dismutase (SOD) assays. Overall, neither pure BT NP or BT NP/alginate 3D scaffold induced cytotoxicity. The scanning electron and atomic force microscopy revealed that BT NP/alginate 3D scaffold produced exhibited highly interconnected pores and surface nanotopography that were favorable for MSC differentiation. Von Kossa staining showed mineralization nodules and MSCs morphology changed from spindle to cuboid shape after 21 d. Finally, BMP-2 and ALP mRNA were significantly upregulated on cells grown into the BT NP/alginate 3D scaffold. Thus, the BT NP/alginate 3D scaffold showed an osteogenic differentiation induction potential, without the addition of osteogenic supplements. These results indicate that the BT NP/alginate 3D scaffold provides a cytocompatible and bioactive microenvironment for osteogenic human MSC differentiation.


Assuntos
Alginatos/química , Compostos de Bário/química , Nanopartículas Metálicas/química , Células-Tronco/citologia , Tecidos Suporte/química , Titânio/química , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Humanos , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Microscopia Eletrônica de Varredura , Osteogênese , Estresse Oxidativo , Polímeros/química , Análise Espectral Raman , Engenharia Tecidual/métodos
5.
Luminescence ; 34(2): 255-260, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30697894

RESUMO

The BaB2 O4 :Eu3+ nano/microphosphors with sphere-, rod-, and granular-like morphologies were successfully obtained by a two-step method using Ba-B-O:Eu3+ as the precursor. The structure, morphology and photoluminescent properties of the products were characterized by Fourier transfer infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), scanning electron microscopy (SEM) and photoluminescence (PL). The formation mechanisms of Ba-B-O:Eu3+ and BaB2 O4 :Eu3+ were proposed. The results show that the BaB2 O4 :Eu3+ could retain the original morphologies of their respective precursors largely. The BaB2 O4 :Eu3+ prepared by this two-step method exhibited better morphology, smaller particle size and better crystallinity than when prepared by a solid-state method. The granular-like BaB2 O4 :Eu3+ red phosphor prepared by this two-step method exhibited stronger PL intensity and better red color purity than when prepared by a solid-state method.


Assuntos
Compostos de Bário/química , Bário/química , Boro/química , Bromatos/química , Európio/química , Luminescência , Nanoestruturas/química , Tamanho da Partícula , Propriedades de Superfície
6.
J Biosci Bioeng ; 127(3): 265-272, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30243531

RESUMO

Alcohol oxidase catalyzes the oxidation of primary alcohols into the corresponding aldehydes, making it a potential biocatalyst in the chemical industry. However, the high production cost and poor operational stability of this enzyme are limitations for industrial application. Immobilization of enzyme onto solid supports is a useful strategy for improving enzyme stability. In this work, alcohol oxidase from the thermotolerant methylotrophic yeast Ogataea thermomethanolica (OthAOX) was covalently immobilized onto barium ferrite (BaFe12O19) magnetic microparticles. Among different conditions tested, the highest immobilization efficiency of 71.0 % and catalytic activity of 34.6 U/g was obtained. Immobilization of OthAOX onto magnetic support was shown by Fourier-Transformed infrared microscopy, scanning electron microscopy and X-ray diffraction. The immobilized OthAOX worked optimally at 55 °C and pH 8.0. Immobilization also improved thermostability, in which >65% of the initial immobilized enzyme activity was retained after 24 h pre-incubation at 45 °C. The immobilized enzyme showed a greater catalytic efficiency for oxidation of methanol and ethanol than free enzyme. The immobilized enzyme could be recovered by magnetization and recycled for at least three consecutive batches, after which 70% activity remained. The properties of the immobilized enzyme suggest its potential industrial application for synthesis of aldehyde.


Assuntos
Oxirredutases do Álcool/química , Compostos de Bário/química , Compostos de Bário/síntese química , Enzimas Imobilizadas/química , Compostos Férricos/química , Compostos Férricos/síntese química , Imãs/química , Microesferas , Saccharomycetales/enzimologia , Oxirredutases do Álcool/metabolismo , Biocatálise , Técnicas de Química Sintética , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Metanol/química , Temperatura
7.
J Colloid Interface Sci ; 538: 449-461, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30537658

RESUMO

Major obstacles to the successful treatment of gliolastoma multiforme are mostly related to the acquired resistance to chemotherapy drugs and, after surgery, to the cancer recurrence in correspondence of residual microscopic foci. As innovative anticancer approach, low-intensity electric stimulation represents a physical treatment able to reduce multidrug resistance of cancer and to induce remarkable anti-proliferative effects by interfering with Ca2+ and K+ homeostasis and by affecting the organization of the mitotic spindles. However, to preserve healthy cells, it is utterly important to direct the electric stimuli only to malignant cells. In this work, we propose a nanotechnological approach based on ultrasound-sensitive piezoelectric nanoparticles to remotely deliver electric stimulations to glioblastoma cells. Barium titanate nanoparticles (BTNPs) have been functionalized with an antibody against the transferrin receptor (TfR) in order to obtain the dual targeting of blood-brain barrier and of glioblastoma cells. The remote ultrasound-mediated piezo-stimulation allowed to significantly reduce in vitro the proliferation of glioblastoma cells and, when combined with a sub-toxic concentration of temozolomide, induced an increased sensitivity to the chemotherapy treatment and remarkable anti-proliferative and pro-apoptotic effects.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Compostos de Bário/química , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Nanopartículas/química , Temozolomida/farmacologia , Titânio/química , Antineoplásicos Alquilantes/química , Apoptose/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Encefálicas/patologia , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma/patologia , Humanos , Nanotecnologia , Temozolomida/química , Células Tumorais Cultivadas
8.
Chemosphere ; 219: 277-285, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30543963

RESUMO

Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO3 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO3 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 µW cm-2 in 10 mg L-1 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO3 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO3 was also discussed.


Assuntos
Fontes de Energia Elétrica , Química Verde/métodos , Triazinas/química , Compostos de Bário/química , Carbono/química , Eletricidade , Eletrodos , Óxido de Zinco/química
9.
Molecules ; 23(12)2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30513779

RESUMO

The nature of precursor phenomena in the paraelectric phase of ferroelectrics is one of the main questions to be resolved from a fundamental point of view. Barium titanate (BaTiO3) is one of the most representative perovskite-structured ferroelectrics intensively studied until now. The pretransitional behavior of BaTiO3 single crystal grown using a solid-state crystal growth (SSCG) method was investigated for the first time and compared to previous results. There is no melting process in the SSCG method, thus the crystal grown using a SSCG method have inherent higher levels of impurity and defect concentrations, which is a good candidate for investigating the effect of crystal quality on the precursor phenomena. The acoustic, dielectric, and piezoelectric properties, as well as birefringence, of the SSCG-grown BaTiO3 were examined over a wide temperature range. Especially, the acoustic phonon behavior was investigated in terms of Brillouin spectroscopy, which is a complementary technique to Raman spectroscopy. The obtained precursor anomalies of the SSCG-grown BaTiO3 in the cubic phase were similar to those of other single crystals, in particular, of high-quality single crystal grown by top-seeded solution growth method. These results clearly indicate that the observed precursor phenomena are common and intrinsic effect irrespective of the crystal quality.


Assuntos
Compostos de Bário/química , Bário/química , Birrefringência , Difusão Dinâmica da Luz , Cristalização , Análise Espectral , Temperatura
10.
Pharmazie ; 73(10): 555-558, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30223917

RESUMO

The "second identification" of drugs in pharmacies and hospital pharmacies affords the availability of easy to perform and robust tests. Besides determination of melting points and simple chromatography (TLC), reliable color and precipitation reactions are common techniques for this purpose. Preferentially, these reactions allow for the identification of typical functional groups in the drugs. Here we present a reaction for identification of carbamate-type drugs, based on the precipitation of barium carbonate upon treating the analytes with barium hydroxide solution at 80 °C. This method works well for carbamate drugs with noteworthy water solubility like carbachol, neostigmine bromide, and pyridostigmine bromide, and could be considered as a method for second identification of these drugs in pharmacopoeias and in Deutscher Arzneimittel-Codex/Neues Rezeptur-Formularium (DAC-NRF).


Assuntos
Carbamatos/análise , Bário/química , Compostos de Bário/química , Carbamatos/química , Carbonatos/química , Precipitação Química , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/química
11.
Mater Sci Eng C Mater Biol Appl ; 92: 424-434, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184768

RESUMO

Peptic ulcer is prevalent in about 4% of the world population and nearly 10% of people have been affected by peptic ulcer at some point in their life. Therefore, there is a need for newer efficient and safe anti-ulcer agents. In the present strategy, we have prepared a novel bioactive glass containing 1.3 mol% of barium oxide (BaBG) and evaluated its antiulcer potential in gastroduodenal ulcer models. Prophylactic effect of BaBG pretreatment was evaluated for 5 days in ethanol, aspirin and pyloric ligation-induced gastric ulcer and cysteamine-induced duodenal ulcer models. Repeated treatment of 10 days of BaBG was evaluated in the healing ulcer model of acetic acid. BaBG significantly reduced the ulcerative damage against all the five tested ulcer models. Scanning electron microscope (SEM) images have shown that BaBG forms a physical protective barrier over the gastro-duodenal epithelium cell. In the pyloric-ligation, ethanol and aspirin models, BaBG showed significantly increased in gastric pH, indicating antacid like activity. BaBG treatment significantly increased cell proliferation in the pyloric model. Thus, BaBG mediates antiulcer action by forming a protective physical barrier against harsh luminal factors, acid neutralization and cell proliferation.


Assuntos
Compostos de Bário , Cerâmica , Úlcera Duodenal/tratamento farmacológico , Óxidos , Úlcera Gástrica/tratamento farmacológico , Animais , Bário/química , Bário/farmacologia , Compostos de Bário/química , Compostos de Bário/farmacologia , Cerâmica/química , Cerâmica/farmacologia , Cisteamina/efeitos adversos , Cisteamina/farmacologia , Modelos Animais de Doenças , Úlcera Duodenal/induzido quimicamente , Úlcera Duodenal/metabolismo , Úlcera Duodenal/patologia , Masculino , Óxidos/química , Óxidos/farmacologia , Ratos , Ratos Wistar , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patologia
12.
J Colloid Interface Sci ; 530: 695-703, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30015155

RESUMO

Airborne particulate matter (PM) pollution has become a serious threat to human health, thus it is highly desired for a high-filtration-performance and good-wearing-comfort face mask. Herein, a highly breathable and thermal comfort filter medium consisting of electret polyethersulfone/barium titanate nanofibrous membrane (PES/BaTiO3 NFM) integrated on a nonwoven polypropylene substrate was developed. Benefiting from the high porosity and optimized injection charge energy, the PES/BaTiO3 membrane was endowed with a good air permeability of 743 mm s-1, a modest water vapor permeability of 6.24 kg m-2 d-1, and an enhanced charge storage stability. In addition, the electret PES/BaTiO3 NFM1.5 medium with a low basis weight of 4.32 g m-2 still shows a high filtration efficiency of 99.99% and a low pressure drop of 67 Pa after being treated at 200 °C for 45 min, which is better than that of commercial media. Moreover, 3D simulation based on the characters of composite membrane was processed to graphically express the airflow distribution during the filtration process. Significantly, the NFM1.5 with a high infrared (IR) transmittance of 93.4% led to an effective radiative cooling to human body radiation. This multifunctional fibrous medium design may provide new insights into the development of environmental adaptive protection materials.


Assuntos
Compostos de Bário/química , Filtração/métodos , Máscaras , Membranas Artificiais , Nanofibras/química , Material Particulado/isolamento & purificação , Polímeros/química , Sulfonas/química , Titânio/química , Humanos , Simulação de Dinâmica Molecular , Nanofibras/ultraestrutura , Tamanho da Partícula , Permeabilidade , Polipropilenos/química , Vapor/análise
13.
J Appl Oral Sci ; 26: e20170270, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29742262

RESUMO

Although resin composites are widely used in the clinical practice, the development of recurrent caries at composite-tooth interface still remains as one of the principal shortcomings to be overcome in this field. Objectives To evaluate the activity against S. mutans biofilm of model resin composites incorporating different concentrations of ZnO-nanoparticles (ZnO-NP) and characterize their physicochemical properties. Materials and Methods Different concentrations of ZnO-NP (wt.%): E1=0, E2=0.5, E3=1, E4=2, E5=5 and E6=10 were incorporated into a model resin composite consisting of Bis-GMA-TEGDMA and barium borosilicate particles. The activity against S. mutans biofilm was evaluated by metabolic activity and lactic acid production. The following physicochemical properties were characterized: degree of conversion (DC%), flexural strength (FS), elastic modulus (EM), hardness (KHN), water sorption (Wsp), water solubility (Wsl) and translucency (TP). Results E3, E4, E5 and E6 decreased the biofilm metabolic activity and E5 and E6 decreased the lactic acid production (p<0.05). E6 presented the lowest DC% (p<0.05). No significant difference in FS and EM was found for all resin composites (p>0.05). E5 and E6 presented the lowest values of KHN (p<0.05). E6 presented a higher Wsp than E1 (p<0.05) and the highest Wsl (p<0.05). The translucency significantly decreased as the ZnO- NP concentration increased (p<0.05). Conclusions The incorporation of 2 - 5 wt.% of ZnO-NP could endow antibacterial activity to resin composites, without jeopardizing their physicochemical properties.


Assuntos
Resinas Compostas/química , Resinas Compostas/farmacologia , Nanopartículas/química , Streptococcus mutans/efeitos dos fármacos , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Análise de Variância , Compostos de Bário/química , Compostos de Bário/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Bis-Fenol A-Glicidil Metacrilato/química , Bis-Fenol A-Glicidil Metacrilato/farmacologia , Módulo de Elasticidade , Testes de Dureza , Modelos Lineares , Teste de Materiais , Microscopia Eletrônica de Varredura , Maleabilidade , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Silicatos/química , Silicatos/farmacologia , Solubilidade , Streptococcus mutans/crescimento & desenvolvimento , Propriedades de Superfície , Água/química
14.
J Biomater Appl ; 32(10): 1464-1475, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29621929

RESUMO

The goal of our study is to design BaTiO3 ferroelectric layers that will cover metal implants and provide improved osseointegration. We synthesized ferroelectric BaTiO3 layers on Pt/fused silica substrates, and we studied their physical and bio-properties. BaTiO3 and Pt layers were prepared using KrF excimer laser ablation at substrate temperature Ts in the range from 200°C to 750°C in vacuum or under oxygen pressure of 10 Pa, 15 Pa, and 20 Pa. The BaTiO3/Pt and Pt layers adhered well to the substrates. BaTiO3 films of crystallite size 60-140 nm were fabricated. Ferroelectric loops were measured and ferroelectricity was also confirmed using Raman scattering measurements. Results of atomic force microscopy topology and the X-ray diffraction structure of the BaTiO3/Pt/fused silica multilayers are presented. The adhesion, viability, growth, and osteogenic differentiation of human osteoblast-like Saos-2 cells were also studied. On days 1, 3, and 7 after seeding, the lowest cell numbers were found on non-ferroelectric BaTiO3, while the values on ferroelectric BaTiO3, on non-annealed and annealed Pt interlayers, and on the control tissue culture polystyrene dishes and microscopic glass slides were similar, and were usually significantly higher than on non-ferroelectric BaTiO3. A similar trend was observed for the intensity of the fluorescence of alkaline phosphatase, a medium-term marker of osteogenic differentiation, and of osteocalcin, a late marker of osteogenic differentiation. At the same time, the cell viability, tested on day 1 after seeding, was very high on all tested samples, reaching 93-99%. Ferroelectric BaTiO3 films deposited on metallic bone implants through a Pt interlayer can therefore markedly improve the osseointegration of these implants in comparison with non-ferroelectric BaTiO3 films.


Assuntos
Compostos de Bário/química , Substitutos Ósseos/química , Nanopartículas/química , Platina/química , Dióxido de Silício/química , Titânio/química , Linhagem Celular , Eletricidade , Humanos , Lasers , Nanopartículas/ultraestrutura , Osteoblastos/citologia , Osteogênese , Próteses e Implantes
15.
J Vis Exp ; (133)2018 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-29658917

RESUMO

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its well-balanced ferroelectricity, piezoelectricity, and dielectric constant. In addition, BT does not contain any toxic elements. Therefore, it is considered to be an eco-friendly material, which has attracted considerable interest as a replacement for lead zirconate titanate (PZT). However, bulk BT loses its ferroelectricity at approximately 130 °C, thus, it cannot be used at high temperatures. Because of the growing demand for high-temperature ferroelectric materials, it is important to enhance the thermal stability of ferroelectricity in BT. In previous studies, strain originating from the lattice mismatch at hetero-interfaces has been used. However, the sample preparation in this approach requires complicated and expensive physical processes, which are undesirable for practical applications. In this study, we propose a chemical synthesis of a porous material as an alternative means of introducing strain. We synthesized a porous BT thin film using a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles were used as an organic template. Through a series of studies, we clarified that the introduction of pores had a similar effect on distorting the BT crystal lattice, to that of a hetero-interface, leading to the enhancement and stabilization of ferroelectricity. Owing to its simplicity and cost effectiveness, this fabrication process has considerable advantages over conventional methods.


Assuntos
Compostos de Bário/química , Compostos de Bário/síntese química , Porosidade , Titânio/química
16.
Acta Biomater ; 72: 287-294, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29578086

RESUMO

We report sub-100 nm metal-shell (Au) dielectric-core (BaTiO3) nanoparticles with bimodal imaging abilities and enhanced photothermal effects. The nanoparticles efficiently absorb light in the near infrared range of the spectrum and convert it to heat to ablate tumors. Their BaTiO3 core, a highly ordered non-centrosymmetric material, can be imaged by second harmonic generation, and their Au shell generates two-photon luminescence. The intrinsic dual imaging capability allows investigating the distribution of the nanoparticles in relation to the tumor vasculature morphology during photothermal ablation. Our design enabled in vivo real-time tracking of the BT-Au-NPs and observation of their thermally-induced effect on tumor vessels. STATEMENT OF SIGNIFICANCE: Photothermal therapy induced by plasmonic nanoparticles has emerged as a promising approach to treating cancer. However, the study of the role of intratumoral nanoparticle distribution in mediating tumoricidal activity has been hampered by the lack of suitable imaging techniques. This work describes metal-shell (Au) dielectric-core (BaTiO3) nanoparticles (abbreviated as BT-Au-NP) for photothermal therapy and bimodal imaging. We demonstrated that sub-100 nm BT-Au-NP can efficiently absorb near infrared light and convert it to heat to ablate tumors. The intrinsic dual imaging capability allowed us to investigate the distribution of the nanoparticles in relation to the tumor vasculature morphology during photothermal ablation, enabling in vivo real-time tracking of the BT-Au-NPs and observation of their thermally-induced effect on tumor vessels.


Assuntos
Adenocarcinoma/terapia , Compostos de Bário , Ouro , Hipertermia Induzida , Neoplasias Mamárias Experimentais/terapia , Nanopartículas , Fototerapia , Titânio , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Compostos de Bário/química , Compostos de Bário/farmacocinética , Compostos de Bário/farmacologia , Linhagem Celular Tumoral , Feminino , Ouro/química , Ouro/farmacocinética , Ouro/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Nus , Nanopartículas/química , Nanopartículas/uso terapêutico , Titânio/química , Titânio/farmacocinética , Titânio/farmacologia
17.
J Labelled Comp Radiopharm ; 61(7): 522-532, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29431234

RESUMO

Since the inception of radiation synovectomy, a host of radioactive colloids and microparticles incorporating suitable therapeutic radionuclides have been proposed for the treatment of arthritis. The present article reports the synthesis and evaluation of barium titanate microparticles as an innovative and effective carrier platform for lanthanide radionuclides in the preparation of therapeutic agents for treatment of arthritis. The material was synthesized by mechanochemical route and characterized by X-ray diffraction, scanning electron microscopy, surface area, and particle size distribution analyses. Loading of lanthanide radionuclides (166 Ho, 153 Sm, 177 Lu, and 169 Er) on the microparticles was achieved in high yield (> 95%) resulting in the formulation of loaded particulates with excellent radiochemical purities (> 99%). Radiolanthanide-loaded microparticles exhibited excellent in vitro stability in human serum. In vitro diethylene triamine pentaacetic acid challenge study indicated fairly strong chemical association of lanthanides with barium titanate microparticles. Long-term biodistribution studies carried out after administration of 177 Lu-loaded microparticles into one of the knee joints of normal Wistar rats revealed near-complete retention of the formulation (> 96% of the administered radioactivity) within the joint cavity even 14 days post-administration. The excellent localization of the loaded microparticles was further confirmed by sequential whole-body radio-luminescence imaging studies carried out using 166 Ho-loaded microparticles.


Assuntos
Artrite/radioterapia , Compostos de Bário/química , Portadores de Fármacos/química , Elementos da Série dos Lantanídeos/química , Elementos da Série dos Lantanídeos/uso terapêutico , Microesferas , Titânio/química , Animais , Compostos de Bário/farmacocinética , Fenômenos Químicos , Portadores de Fármacos/farmacocinética , Estabilidade de Medicamentos , Radioquímica , Radioisótopos , Ratos , Ratos Wistar , Distribuição Tecidual , Titânio/farmacocinética
18.
Biol Trace Elem Res ; 185(2): 316-326, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29399740

RESUMO

Inducing the differentiation of stem cells from human exfoliated deciduous teeth (SHEDs) proceeds with low efficiency, which greatly limits clinical applications. Divalent metal elements play an important role in osteoinductivity for bone remodeling because they can simulate bone formation and decrease bone resorption. The purpose of this study was to investigate the effect of some divalent metal phosphates on osteogenic differentiation from human exfoliated deciduous teeth. These divalent metal ions can be gradually released from the scaffold into the culture medium and continually induce osteoblastic differentiation. Experimental results revealed that SHEDs cultured in chitosan scaffolds containing divalent metal phosphates had notably increased osteoblastic differentiation compared with cells cultured without divalent metal phosphates. This effect was due to the high activity of alkaline phosphatase, as well as the bone-related gene expression of collagen type I, Runx2, osteopontin, osteocalcin, VEGF, and Ang-1, shown through RT-PCR and bone-related protein immunocytochemistry stains. A calcium-content assay further revealed significant enhancement of deposited minerals on the scaffolds after 21 days of culture, particularly for magnesium phosphate and zinc phosphate. Thus, divalent metals, except for barium phosphate, effectively promoted SHED cell differentiation and osteoblastic cell maturation. This study demonstrated that the divalent metal elements magnesium, strontium, and zinc could effectively induce SHED osteoblastic differentiation for use in tissue engineering and bone repair.


Assuntos
Quitosana/farmacologia , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Dente Decíduo/citologia , Compostos de Bário/síntese química , Compostos de Bário/química , Compostos de Bário/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Criança , Quitosana/química , Humanos , Compostos de Magnésio/síntese química , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Fosfatos/síntese química , Fosfatos/química , Fosfatos/farmacologia , Estrôncio/química , Estrôncio/farmacologia , Compostos de Zinco/síntese química , Compostos de Zinco/química , Compostos de Zinco/farmacologia
19.
Small ; 14(8)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29356374

RESUMO

While nanoparticles are an increasingly popular choice for labeling and tracking stem cells in biomedical applications such as cell therapy, their intracellular fate and subsequent effect on stem cell differentiation remain elusive. To establish an effective stem cell labeling strategy, the intracellular nanocrystal concentration should be minimized to avoid adverse effects, without compromising the intensity and persistence of the signal necessary for long-term tracking. Here, the use of second-harmonic generating barium titanate nanocrystals is reported, whose achievable brightness allows for high contrast stem cell labeling with at least one order of magnitude lower intracellular nanocrystals than previously reported. Their long-term photostability enables to investigate quantitatively at the single cell level their cellular fate in hematopoietic stem cells (HSCs) using both multiphoton and electron microscopy. It is found that the concentration of nanocrystals in proliferative multipotent progenitors is over 2.5-fold greater compared to quiescent stem cells; this difference vanishes when HSCs enter a nonquiescent, proliferative state, while their potency remains unaffected. Understanding the nanoparticle stem cell interaction allows to establish an effective and safe nanoparticle labeling strategy into somatic stem cells that can critically contribute to an understanding of their in vivo therapeutic potential.


Assuntos
Compostos de Bário/química , Células-Tronco Hematopoéticas/citologia , Nanopartículas de Magnetita/química , Nanopartículas/química , Microscopia de Geração do Segundo Harmônico/métodos , Titânio/química , Células-Tronco Adultas/citologia , Animais , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Proliferação de Células/fisiologia , Humanos
20.
Nanomedicine (Lond) ; 13(4): 423-438, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29345190

RESUMO

AIM: We studied externally controlled anticancer effects of binding tumor growth inhibiting synthetic peptides to magnetoelectric nanoparticles (MENs) on treatment of glioblastomas. METHODS: Hydrothermally synthesized 30-nm MENs had the core-shell composition of CoFe2O4@BaTiO3. Molecules of growth hormone-releasing hormone antagonist of the MIA class (MIA690) were chemically bound to MENs. In vitro experiments utilized human glioblastoma cells (U-87MG) and human brain microvascular endothelial cells. RESULTS: The studies demonstrated externally controlled high-efficacy binding of MIA690 to MENs, targeted specificity to glioblastoma cells and on-demand release of the peptide by application of d.c. and a.c. magnetic fields, respectively. CONCLUSION: The results support the use of MENs as an effective drug delivery carrier for growth hormone-releasing hormone antagonists in the treatment of human glioblastomas.


Assuntos
Antineoplásicos/química , Neoplasias Encefálicas/tratamento farmacológico , Portadores de Fármacos/química , Glioblastoma/tratamento farmacológico , Hormônio do Crescimento/antagonistas & inibidores , Nanopartículas de Magnetita/química , Peptídeos/química , Antineoplásicos/administração & dosagem , Compostos de Bário/química , Encéfalo/irrigação sanguínea , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cobalto/química , Liberação Controlada de Fármacos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Compostos Férricos/química , Hormônio do Crescimento/metabolismo , Antagonistas de Hormônios/uso terapêutico , Humanos , Campos Magnéticos , Microvasos/citologia , Nanosferas/química , Tamanho da Partícula , Peptídeos/administração & dosagem , Titânio/química
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