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1.
J Mater Sci Mater Med ; 30(9): 104, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31493056

RESUMO

Currently, titanium and its alloys are the most used materials for biomedical applications. However, because of the high costs of these metals, new materials, such as niobium, have been researched. Niobium appears as a promising material due to its biocompatibility, and excellent corrosion resistance. In this work, anodized niobium samples were produced and characterized. Their capacity to support the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs) was also tested. The anodized niobium samples were characterized by SEM, profilometry, XPS, and wettability. BM-MSCs were cultured on the samples during 14 days, and tested for cell adhesion, metabolic activity, alkaline phosphatase activity, and mineralization. Results demonstrated that anodization promotes the formation of a hydrophilic nanoporous oxide layer on the Nb surface, which can contribute to the increase in the metabolic activity, and in osteogenic differentiation of BM-MSCs, as well as to the extracellular matrix mineralization.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Nióbio/farmacologia , Osteogênese/efeitos dos fármacos , Tecidos Suporte , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/fisiologia , Células Cultivadas , Eletrólise , Feminino , Temperatura Alta , Teste de Materiais , Células-Tronco Mesenquimais/fisiologia , Nióbio/química , Oxirredução , Ratos , Ratos Endogâmicos SHR , Propriedades de Superfície , Tecidos Suporte/química
2.
Colloids Surf B Biointerfaces ; 182: 110386, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31369954

RESUMO

Effective methods of accelerating the bone regeneration healing process are in demand for a number of bone-related diseases and trauma. This work developed scaffolds with improved properties for bone tissue engineering by electrospinning composite polycaprolactone-gelatin-hydroxyapatite-niobium pentoxide (PGHANb) membranes. Composite membranes, with average fiber diameters ranging from 123 to 156 nm, were produced by adding hydroxyapatite (HA) and varying concentrations of niobium pentoxide (Nb2O5) particles (0, 3, 7, and 10 wt%) to a polycaprolactone (PCL) and gelatin (GL) matrix prior to electrospinning. The morphology, mechanical, chemical and biological properties of resultant membranes were evaluated. Bioactivity was assessed using simulated body fluid (SBF) and it confirmed that the presence of particles induced the formation of hydroxyapatite crystals on the surface of the membranes. Samples were hydrophilic and cell metabolism results showed that the niobium-containing membranes were non-toxic while improving cell proliferation and differentiation compared to controls. This study demonstrated that electrospun membranes containing HA and Nb2O5 particles have potential to promote cell adhesion and proliferation while exhibiting bioactive properties. PGHANb membranes are promising candidates for bone tissue engineering applications.


Assuntos
Osso e Ossos/fisiologia , Durapatita/química , Gelatina/química , Membranas Artificiais , Nióbio/química , Óxidos/química , Poliésteres/química , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Óssea , Osso e Ossos/ultraestrutura , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas Eletroquímicas/métodos , Humanos , Microscopia Eletrônica , Tamanho da Partícula , Tecidos Suporte/química
3.
J Mater Sci Mater Med ; 30(8): 91, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31388766

RESUMO

Customized porous titanium alloys have become the emerging materials for orthopaedic implant applications. In this work, diamond and rhombic dodecahedron porous Ti-33Nb-4Sn scaffolds were fabricated by selective laser melting (SLM). The phase, microstructure and defects characteristics were investigated systematically and correlated to the effects of pore structure, unit cell size and processing parameter on the mechanical properties of the scaffolds. Fine ß phase dendrites were obtained in Ti-33Nb-4Sn scaffolds due to the fast solidification velocity in SLM process. The compressive and bending strength of the scaffolds decrease with the decrease of strut size and diamond structures showed both higher compressive and bending strength than the dodecahedron structures. Diamond Ti-33Nb-4Sn scaffold with compressive strength of 76 MPa, bending strength of 127 MPa and elastic modulus of 2.3 GPa was achieved by SLM, revealing the potential of Ti-33Nb-4Sn scaffolds for applications on orthopaedic implant.


Assuntos
Nióbio/química , Equipamentos Ortopédicos , Próteses e Implantes , Estanho/química , Tecidos Suporte/química , Titânio/química , Ligas/síntese química , Ligas/química , Materiais Biocompatíveis , Fenômenos Biomecânicos , Força Compressiva , Módulo de Elasticidade , Manufaturas/análise , Teste de Materiais , Ortopedia , Porosidade , Próteses e Implantes/ultraestrutura , Estresse Mecânico , Propriedades de Superfície
4.
Biomed Microdevices ; 21(3): 61, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273538

RESUMO

The aim of the study was to show in vitro the greater inertness to the corrosion body fluid of TiNbN coating than the CoCrMo alloy substrate. The prosthetic component under study was a femoral component of total knee prosthesis in CoCrMo alloy coated in TiNbN with Physical Vapor Deposition technique immersed in static Hank's balanced salt solution (HBS) (pH = 6) for at least 34 months at a constant temperature of 37 °C. Another uncoated prosthetic component of CoCrMo alloy with the same type and size was left in static immersion in the same solution and for the same period of time. Scanning electron microscope (SEM) analysis was performed to investigate adhesion and proliferation at 24, 48, 72 h after seeding of 104 sub-confluents osteoblast-like cells (SaOS-2) cells on scaffold. The results of the study showed a reduction in the concentration of the metal ions released from the TiNbN-coated femoral component surface compared to the uncoated surface in the HBS solution. The overall reduction of the ions for the TiNbN-coated femoral component compared to the uncoated one was 80.1 ± 2%, 62.5% ± 8% and 48% ± 10% for Co, Cr, Mo, respectively (p < 0.01). SEM analysis confirmed the healthy state of the cells, the cellular adhesion and proliferation of SaOS-2 on the TiNbN-coated specimen. Although the results observed in vitro for the TiNbN coating are encouraging, clinical studies are certainly needed to be performed in order to understand how these positive findings can be translated in vivo and to determine the clinical benefit of TiNbN coating.


Assuntos
Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Nióbio/química , Titânio/química , Vitálio/química , Vitálio/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Prótese do Joelho , Teste de Materiais , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Propriedades de Superfície
5.
Chemosphere ; 236: 124318, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31319310

RESUMO

The present paper deals with the atenolol (ATL) degradation by advanced anodic oxidation using a boron-doped diamond anode supported on niobium (Nb/BDD). Cyclic voltammetry performed on this electrode revealed that it presents a high quality (diamond-sp3/sp2-carbon ratio), high potential for OER and that ATL can be oxidized directly and/or indirectly by the electrogenerated oxidants, such as hydroxyl radicals, persulfate ions and sulfate radicals. Electrolysis experiments demonstrated that ATL degradation and mineralization follow a mixed (first and zero) order kinetics depending on the applied current density. At high applied current densities, the amount of OH radicals is very high and the overall reaction is limited by the transport of ATL (pseudo first-order kinetics) whereas for low applied current densities, the rate of OH radicals generation at the anode is slower than the rate of arrival of ATL molecules (pseudo-zero order kinetics). Estimated values of kzero and kfirst based on the assumption of pseudo-zero or pseudo-first order kinetics were carried oud as a function of the supporting electrolyte concentration, indicating that both parameters increased with its concentration due the higher production of sulfate reactive species that play an important role in degradation. Finally, MCE increased with the decrease of current density, due to the lower amount of OH present in solution, since this species could be rapidly wasted in parasitic reactions; and the increase of sulfate concentration due to the more efficient production of persulfate.


Assuntos
Atenolol/uso terapêutico , Eletrólise/métodos , Nióbio/química , Atenolol/farmacologia , Eletrodos
6.
Mater Sci Eng C Mater Biol Appl ; 103: 109755, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349485

RESUMO

A low modulus ß Ti-Nb-Ta-O alloy was subjected to heat treatment to investigate its phase stability upon aging. The resultant effect on the mechanical and functional properties was systematically evaluated. The aging of the ß-only microstructure, obtained by solutionizing and quenching, resulted in the formation of ultrafine α-precipitates with increasing order of size as the aging temperature increased from 400 °C to 600 °C. The variation in the size of α-precipitates effected the mechanical properties at the three different aging temperature. The highest hardening observed at 400 °C was associated with macroscopic embrittlement, whereas age softening was observed in samples aged at 600 °C due to coarsening of precipitates and softening of the ß-matrix. In contrast, aging at 500 °C resulted in about 32% increase in tensile strength from the ß-solutionized condition. As the samples aged at 500 °C showed optimum combination of mechanical properties among the aged samples, these were further characterized for their electrochemical, tribological and biological responses. The fretting wear studies showed that the wear rate of the solution-treated samples increased after aging due to the higher corrosion rate leading to a higher rate of tribocorrosive dissolution and formation of a transfer layer harder than that of solution treated sample. The Ti-Nb-Ta-O alloy supported the attachment and proliferation of osteoblasts similar to that on commercially pure Ti. Taken together, this work provides new insights into the preparation of next-generation Ti alloys for biomedical applications with high strength and low modulus through microstructural control induced by heat treatment.


Assuntos
Ligas/química , Teste de Materiais , Osteoblastos/citologia , Animais , Adesão Celular , Proliferação de Células , Espectroscopia Dielétrica , Módulo de Elasticidade , Camundongos , Nióbio/química , Tantálio/química , Temperatura Ambiente , Resistência à Tração , Titânio/química , Difração de Raios X
7.
Chemosphere ; 230: 479-487, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31121511

RESUMO

The destruction of toluene in a dielectric barrier discharge (DBD) reactor with Nb-Mn/MCM-41 had been investigated and compared with X (X = Cu, Ce, Co)-Mn/MCM-41 catalysts. The XRD and TEM result confirms that the metal species were highly dispersed on the MCM-41. The results of XPS, O2-TPD and H2-TPR clearly demonstrate that Nb doping facilitated formation of lattice oxygen (Olatt) and the acid sites, which are all beneficial to catalytic degradation of toluene. Compared to X (Cu, Ce, Co)-Mn/MCM-41, Nb-Mn/MCM-41 had the most contents of Olatt, the most amounts of acid sites and the strongest acidity. Consequently, the catalytic performance tests identify that Nb-Mn/MCM-41 had the best catalytic performance, the highest removal efficiency and CO2 selectivity as well as carbon balance especially at low SIE. These results indicate that Nb was an important promoter improving the activity and CO2 selectivity of Mn/MCM-41 for the decomposition of toluene in NTP-catalysis system.


Assuntos
Técnicas Eletroquímicas/métodos , Manganês/química , Nióbio/química , Gases em Plasma/química , Dióxido de Silício/química , Tolueno/análise , Catálise , Poluentes Ambientais/análise , Modelos Teóricos , Oxirredução , Óxidos , Compostos Orgânicos Voláteis/análise
8.
Biofouling ; 35(2): 173-186, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30935231

RESUMO

The chemical composition of biomaterials can drive their biological responses; therefore, this in vitro study aimed to evaluate the proteomic profile of the salivary pellicle formed on titanium (Ti) alloys containing niobium (Nb) and zirconium (Zr). The experimental groups consisted of Ti35NbxZr (x = 5 and 10 wt%) alloys, and commercially pure titanium (cpTi); titanium aluminium vanadium (Ti6Al4V) alloys were used as controls. The physical and chemical characteristics of the Ti materials were analysed. The proteomic profile was evaluated by liquid chromatography coupled with tandem mass spectrometry. Bacterial adhesion (2 h) of mixed species (Streptococcus sanguinis and Actinomyces naeslundii) was investigated as colony-forming units (n = 6). This paper reports the finding that salivary pellicle composition can be modulated by the composition of the Ti material. The Ti35NbxZr group showed a significant ability to adsorb proteins from saliva, which can favour interactions with cells and compatibility with the body.


Assuntos
Ligas/química , Película Dentária/química , Nióbio/química , Proteoma/análise , Proteínas e Peptídeos Salivares/análise , Titânio/química , Zircônio/química , Adsorção , Aderência Bacteriana , Materiais Biocompatíveis/química , Proteômica
9.
Bull Exp Biol Med ; 166(5): 686-688, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30903505

RESUMO

Superelastic titanium alloys (titanium-niobium-zirconium and titanium-niobium-tantalum) are considered to be the more advantageous choice for dental implants than titanium alloys due to their physico-mechanical properties close to those of the bone tissue. Morphological studies of the biocompatibility of these alloys in comparison with titanium were carried out in vivo. Scanning electron microscopy and microprobe elemental analysis of the tissue along the interface between the bone and titanium/superelastic titanium alloys showed similar morphology and elemental composition both on days 30 (poorly mineralized connective tissue was detected in sites of contact with titanium alloy samples) and 90 after surgery (the surface of the titanium alloy samples was covered with mineralized tissue similar by its composition to the surrounding bone).


Assuntos
Ligas/química , Nióbio/química , Tantálio/química , Titânio/química , Zircônio/química , Animais , Microscopia Eletrônica de Varredura , Osseointegração , Coelhos
10.
Nanoscale ; 11(12): 5684-5692, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30855052

RESUMO

A type of memristor with a structure of Pd/Nb : AlNO/Pd was designed and fabricated in this work. Its filaments are embedded by phase-change NbO nanoclusters confirmed by the analysis of cross-sectional profiles. The resistive switching mechanism includes the contribution of oxygen vacancy (VO) migration and the structural evolution of phase-change nanoclusters. The system experiences two types of kinetics under external stimulations to replicate the critical dynamics in real synapses: VO migration corresponding to the dynamics of the Ca2+ flux and transmitter release at the pre-synapse, and the phase change of the NbO nanoclusters corresponding to the ionic flux modulated by the post-synaptic potential (current). It was found that the memristor can respond to a set of pulse stimulations in a pattern containing a slow linear increase term and a periodic oscillation term, suggesting that the output signals might be encoded. The simulation of long-term plasticity indicates that the memristor is suitable for diverse learning protocols, including spike-rate dependent plasticity and spike-timing-dependent plasticity. Our work proposes an elementary cell that closely approximates biological synapses and is usable for brain-like computing.


Assuntos
Nanoestruturas/química , Alumínio/química , Cálcio/metabolismo , Eletricidade , Microscopia Eletrônica de Transmissão , Modelos Biológicos , Nióbio/química , Óxidos/química , Paládio/química , Tamanho da Partícula , Espectrometria por Raios X , Sinapses/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-30845691

RESUMO

This work evaluated the performance of an electrochemical oxidation process (EOP), using boron-doped diamond on niobium substrate (Nb/BDD), for the treatment of a reverse osmosis concentrate (ROC) produced from a petrochemical wastewater. The effects of applied current density (5, 10, or 20 mA·cm-2) and oxidation time (0 to 5 h) were evaluated following changes in chemical oxygen demand (COD) and total organic carbon (TOC). Current efficiency and specific energy consumption were also evaluated. Besides, the organic byproducts generated by EOP were analyzed by gas chromatography coupled to mass spectrometry (GC⁻MS). The results show that current densities and oxidation time lead to a COD and TOC reduction. For the 20 mA·cm-2, changes in the kinetic regime were found at 3 h and associated to the oxidation of inorganic ions by chlorinated species. After 3 h, the oxidants act in the organic oxidation, leading to a TOC removal of 71%. Although, due to the evolution of parallel reactions (O2, H2O2, and O3), the specific energy consumption also increased, the resulting consumption value of 66.5 kW·h·kg-1 of COD is considered a low energy requirement representing lower treatment costs. These results encourage the applicability of EOP equipped with Nb/BDD as a treatment process for the ROC.


Assuntos
Técnicas Eletroquímicas/métodos , Nióbio/química , Petróleo/análise , Análise da Demanda Biológica de Oxigênio , Indústria Química , Cromatografia Gasosa-Espectrometria de Massas , Osmose , Águas Residuárias , Purificação da Água
12.
Adv Mater ; 31(16): e1900009, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30843629

RESUMO

Tailored construction of advanced carbon hosts is playing a great role in the development of high-performance lithium-sulfur batteries (LSBs). Herein, a novel N,P-codoped trichoderma spore carbon (TSC) with a bowl structure, prepared by a "trichoderma bioreactor" and annealing process is reported. Moreover, TSC shows excellent compatibility with conductive niobium carbide (NbC), which is in situ implanted into the TSC matrix in the form of nanoparticles forming a highly porous TSC/NbC host. Importantly, NbC plays a dual role in TSC for not only pore formation but also enhancement of conductivity. Excitingly, the sulfur can be well accommodated in the TSC/NbC host forming a high-performance TSC/NbC-S cathode, which exhibits greatly enhanced rate performance (810 mAh g-1 at 5 C) and long cycling life (937.9 mAh g-1 at 0.1 C after 500 cycles), superior to TSC-S and other carbon/S counterparts due to the larger porosity, higher conductivity, and better synergetic trapping effect for the soluble polysulfide intermediate. The synergetic work of porous the conductive architecture, heterodoped N&P polar sites in TSC and polar conductive NbC provides new opportunities for enhancing physisorption and chemisorption of polysulfides leading to higher capacity and better rate capability.


Assuntos
Nióbio/química , Esporos Fúngicos/metabolismo , Enxofre/química , Trichoderma/metabolismo , Fontes de Energia Bioelétrica , Condutividade Elétrica , Técnicas Eletroquímicas , Eletrodos , Nióbio/metabolismo , Porosidade , Sulfetos/química , Termodinâmica
13.
Biosens Bioelectron ; 130: 95-102, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30731351

RESUMO

The paper describes a new biological sensor which represents a resonator based on a segment of a rectangular waveguide of 8 GHz band with shear dimensions of 28.5 × 12.6 mm2. On one side, the resonator is bounded by a metallic short-circuited wall; on the other side, it is bounded by a lithium niobate plate with a porous polystyrene film. This film, applied by centrifugation and modified in high-frequency discharge plasma in argon, was used to immobilize cells of Escherichia coli K-12. This resonator was connected through a coaxial-waveguide adapter to the S parameter meter, by means of which the reflection coefficient S11 in the plane of the lithium niobate plate was measured. The addition of an aqueous solution of ampicillin at 4-50 µg/ml to immobilized cells led to a significant change in the reflection coefficient of S11 from - 10.15 dB to - 15.09 dB. At the same time, the resonance frequency changed insignificantly within the range 8.06-8.068 GHz. The optimal time for modifying the polystyrene film for obtaining the required porosity and the optimal time for the immobilization of the bacterial cells were determined. The immobilized cells retained their activity for 4 months at a temperature of 4 °C. The study showed the promise of such a biosensor to determine ß-lactam antibiotics in aqueous solutions by using ampicillin as an example. The limit of detection of the developed biosensor with respect to ampicillin was established (4 µg/ml).


Assuntos
Ampicilina/isolamento & purificação , Técnicas Biossensoriais , Escherichia coli K12/química , Ampicilina/química , Micro-Ondas , Nióbio/química , Óxidos/química , Temperatura Ambiente , Água/química
14.
Mater Sci Eng C Mater Biol Appl ; 97: 275-284, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678912

RESUMO

Low Young's modulus titanium alloys, such as Ti-30Nb-5Ta-3Zr (TNTZ) of this study, were promising biocompatible implant materials. In this work, TNTZ samples with relative density of 96.8%-99.2% were additively manufactured by powder-bed based Selective Laser Melting (SLM) through tuning processing parameters, i.e. varying the point distance between 50 and 75 µm, laser exposure time between 135 and 200 µs, and a fixed laser power of 200 W. The microstructure, elastic properties, fatigue properties and machining accuracy of the fabricated samples have been investigated. Lattice structure TNTZ samples with porosity of 77.23% were also fabricated to further reduce the Young's modulus of the TNTZ. According to the Relative Growth Rate (RGR) value, the as-printed TNTZ samples exhibited no cell cytotoxicity, where they showed even better biocompatibility than the comparative, as-printed Ti-6Al-4V samples. The as-printed TNTZ developed by the study demonstrates good biocompatibility, low stress shielding tendency and high mechanical properties.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Ligas/toxicidade , Animais , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Módulo de Elasticidade , Lasers , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Nióbio/química , Porosidade , Próteses e Implantes , Tantálio/química , Titânio/química , Testes de Toxicidade , Difração de Raios X , Zircônio/química
15.
ACS Appl Mater Interfaces ; 11(3): 3382-3387, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30609347

RESUMO

The numerous advantages of micro- and nanostructures produced by electrospinning (ES) have stimulated enormous interest in this technology with potential application in several fields. However, ES still has some limitations in controlling the geometrical arrangement of the fiber mats so that expensive and time-consuming technologies are usually employed for producing ordered geometries. Here we present a technique that we call "bipolar pyroelectrospinning" (b-PES) for generating ordered arrays of fiber mats in a direct manner by using the bipolar pyroelectric field produced by a periodically poled lithium niobate crystal (PPLN). The b-PES is free from expensive electrodes, nozzles, and masks because it makes use simply of the structured pyroelectric field produced by the PPLN crystal used as collector. The results show clearly the reliability of the technique in producing a wide variety of arrayed fiber mats that could find application in bioengineering or many other fields. Preliminary results of live cells patterning under controlled geometrical constraints is also reported and discussed in order to show potential exploitation as a scaffold in tissue engineering.


Assuntos
Bioengenharia/métodos , Nanofibras/química , Nanoestruturas/química , Engenharia Tecidual , Cristalização , Humanos , Nióbio/química , Óxidos/química
16.
Mater Sci Eng C Mater Biol Appl ; 96: 166-175, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30606522

RESUMO

An ideal dental implant coating should provide a highly protective interface and an osteogenic function. Inspired by the excellent biocompatibility and anti-corrosion of the Nb element, we produced Nb-based oxide, nitride and carbide films as well as the pure metal Nb film for surface enhancement of dental implants, and compare the impact of the nonmetal elements on the electrochemical, tribological, tribo-corrosion and biological performance of the coated implants. The NbC film, composed of a single-phased subniobium carbide, displays mechanical advantages and anticorrosion characteristics that are distinguished from the other composite films, highlighting its potential outstanding protective efficiency for dental implants against corrosion and wear. Rat bone marrow mesenchymal stem cells (rBMSCS) were found more readily to attach, grow and osteogenically differentiate on the NbC film compared to the Nb, NbO and NbN films, indicating the osteogenesis potential of the NbC film. Taken all the results together, it can be concluded that the NbC film have the highest potential for dental implant surface modification.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis , Implantes Dentários , Membranas Artificiais , Células-Tronco Mesenquimais/metabolismo , Nióbio , Osteogênese/efeitos dos fármacos , Animais , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Células-Tronco Mesenquimais/citologia , Nióbio/química , Nióbio/farmacologia , Ratos , Ratos Sprague-Dawley
17.
Mater Sci Eng C Mater Biol Appl ; 96: 466-478, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30606556

RESUMO

Porous titanium­niobium alloys of composition Ti-24Nb, Ti-35Nb and Ti-42Nb were synthesised by electro-deoxidation of sintered oxide discs of mixed TiO2 and Nb2O5 powders in molten CaCl2 at 1173 K, and characterised by XRD, SEM, EDX and residual oxygen analysis. At the lower Nb content a dual-phase α/ß-alloy was formed consisting of hexagonal close-packed and body-centred cubic Ti-Nb, whereas at the higher Nb contents a single-phase ß-alloy was formed of body-centred cubic Ti-Nb. The corrosion behaviour of the alloys prepared was assessed in Hanks' simulated body fluid solution at 310 K over extended periods of time. Potentiodynamic polarisation studies confirmed that the alloys exhibited passivation behaviour, and impedance studies revealed that the passive films formed on the surface of the alloys comprised a bi-layered structure. XPS analysis further proved that this contained hydroxyapatite at the top and native metal oxide underneath. The mechanical properties of the alloys were evaluated, and the elastic moduli and the Vickers hardness were both found to be in the range of that of bone. Overall, Ti-35Nb is proposed to be the best-suited candidate of the materials studied in regard to biomedical applications.


Assuntos
Ligas/química , Ligas/síntese química , Técnicas Eletroquímicas , Nióbio/química , Titânio/química
19.
Colloids Surf B Biointerfaces ; 173: 109-120, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30273871

RESUMO

Biologically safe Ti-based quaternary Ti-Nb-Zr-Si thin film metallic glass (TFMG) was fabricated by sputtering on Titanium alloy (Ti6Al4V or Ti alloy) substrates. A preliminary assessment regarding glass forming ability, thermal stability and corrosion behavior was performed. The amorphous nature of the film is evidenced from the X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) and Selected Area Electron Diffraction (SAED) patterns. Ion scattering spectroscopy (ISS) and X-ray Photoelectron Spectroscopy (XPS) were used to analyse the chemical composition of surface which indicated oxygen on the top surface of the film and confirms the presence of Ti, Nb, Si, Zr without any other impurities. The surface morphology of the film showed a smooth surface as observed from scanning electron microscope (SEM) and atomic force microscope (AFM) analysis. It is found that the TFMG can sustain in the body-fluid, exhibiting superior corrosion resistance and electrochemical stability than the bare titanium. The cytotoxicity studies with L929 fibroblast cells showed that coatings were graded as zero and non-cytotoxic in nature. No hemolysis was observed on the coated surface indicating a better hemocompatibility. Assay using SaOS-2 bone cells showed good growth on the coated surfaces. The calcium assay showed that the SaOS-2 cells grown and differentiated on the control (Tissue Culture Polystyrene) TCPS surface had the highest mineral level. Higher alkaline phosphatase activity is obtained in SaOS-2 osteoblast cell cultures on TFMG than the control.


Assuntos
Ligas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Osteoblastos/efeitos dos fármacos , Tecidos Suporte , Fosfatase Alcalina/metabolismo , Ligas/química , Animais , Biomarcadores/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis/química , Eritrócitos/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Camundongos , Nióbio/química , Nióbio/farmacologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Silício/química , Silício/farmacologia , Propriedades de Superfície , Titânio/química , Titânio/farmacologia , Zircônio/química , Zircônio/farmacologia
20.
Colloids Surf B Biointerfaces ; 175: 463-468, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30572154

RESUMO

The implant infection is one of the most serious postsurgical complications of medical device implantation. Therefore, the development of biocompatible materials with improved antibacterial properties is of great importance. It might be a new insight to apply the intrinsic electrical properties of biomaterials to solve this problem. Here, potassium-sodium niobate piezoceramics (K0.5Na0.5NbO3, KNN) with different piezoelectric constants were prepared, and the microstructures and piezoelectric properties of these piezoceramics were evaluated. Moreover, the antibacterial effect and biocompatibility of these piezoceramics were assayed. Results showed that these piezoceramics were able to decrease the colonies of bacteria staphylococcus aureus (S. aureus), favor the rat bone marrow mesenchymal stem cells (rBMSCs) proliferation and promote the cell adhesion and spreading. The above effects were found closely related to the surface positive charges of the piezoceramics, and the sample bearing the most positive charges on its surface (sample 80KNN) had the best performance in both antibacterial effect and biocompatibility. Based on our work, it is feasible to develop biocompatible antibacterial materials by controlling piezoelectric properties.


Assuntos
Antibacterianos/farmacologia , Cerâmica/farmacologia , Impedância Elétrica , Células-Tronco Mesenquimais/citologia , Nióbio/química , Óxidos/química , Potássio/química , Sódio/química , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Materiais Biocompatíveis/química , Adesão Celular , Proliferação de Células , Células Cultivadas , Cerâmica/química , Desenho de Equipamento , Teste de Materiais , Células-Tronco Mesenquimais/efeitos dos fármacos , Ratos
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