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1.
Ultrason Sonochem ; 62: 104867, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31806551

RESUMO

For the first time, Bi2MoO6 nanofilms were successfully synthesized by simultaneous pulse sonication-pulse electrodeposition (PS-PED) on the stainless steel mesh surface. Bismuth molybdate films were formed under various combinations of electrodeposition and sonication (sono-electrodeposition) in continuous and pulse modes. Porous Bi2MoO6 films synthesized by PS-PED method and showed the highest efficiency in photocatalytic degradation in comparison with other films. Bi2MoO6 film obtained from PS-PED had a thickness of 13.78 nm while, the thickness for the electrodeposition method was 39.52 nm. The high photocatalytic efficiency is attributed to the high surface roughness and low thickness of film synthesized by PS-PED method. Indeed, ultrasound played a key role in the synthesis of films with high surface roughness. On the other hand, shock waves and micro-jets could be dissolved diffusion problems and reduced the dendrite like structures in deposition process. Simultaneous application of pulse modes for both combined methods led to more growth of crystallographic planes. This is due to reaction of ions on the surface in interval relaxation times and produce more nuclei for growth. In order to obtain a high efficiency, response surface methodology was used for optimization of effective variable parameters (ton, toff and sonication amplitude) in film preparation.


Assuntos
Anti-Inflamatórios não Esteroides/química , Bismuto/química , Diclofenaco/química , Galvanoplastia/métodos , Molibdênio/química , Nanoestruturas , Sonicação , Aço Inoxidável/química , Poluentes Químicos da Água/química , Catálise , Processos Fotoquímicos , Propriedades de Superfície
2.
Chemosphere ; 239: 124715, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499311

RESUMO

Electrodeposition is an economical and efficient way to prepare Ti/SnO2-Sb electrode for electrochemical oxidizing pollutants in wastewater. The solvent used for electrodeposition has a great effect on electrode performance. The conventional Ti/SnO2-Sb electrode electrodeposited using aqueous solvent has poor electrochemical activity and short service life. In this study, a Ti/SnO2-Sb electrode was prepared via electrodeposition using a deep eutectic solvent (DES). This new Ti/SnO2-Sb-DES electrode performed a rate constant of 0.571 h-1 for methylene blue decolorization and long accelerated service life of 12.9 h (100 mA cm-2; 0.5 M H2SO4), which were 1.7 times and 3.2 times as high as that of the electrode prepared in aqueous solvent, respectively. The enhanced properties were related to the 1.3 times increased electrochemically active surface area of Ti/SnO2-Sb-DES electrode which had a rough, multilayer and uniform surface structure packed with nano-sized coating particles. In conclusion, this study developed a facile, green and efficient pathway to prepare Ti/SnO2-Sb electrode with high performance.


Assuntos
Antimônio/química , Técnicas Eletroquímicas/métodos , Galvanoplastia/métodos , Solventes/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Eletrodos/normas , Azul de Metileno/química , Oxirredução , Compostos de Estanho/química , Titânio/química , Águas Residuárias/química
3.
ACS Appl Mater Interfaces ; 11(47): 43936-43948, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31696695

RESUMO

One-dimensional nanoneedle-like arrays have emerged as an attractive tool for penetrating the cell membrane to achieve intracellular applications including drug delivery, electrical recording, and biochemical detection. Hollow nanoneedles, also called nanostraws (NSs), combined with nanoelectroporation have been demonstrated as a powerful platform for intracellular drug delivery and extraction of intracellular contents. However, the fabrication technique of nanostraws still requires complicated and expensive atomic layer deposition and etching processes and fails to produce conductive nanostraws. Herein, we developed a commonly accessible and versatile electrodeposition approach to controllably fabricate conductive nanostraw arrays based on various types of metal or conductive polymer materials. Representatively, Pt nanostraws (Pt NSs) with 400 nm diameter were further integrated with a low-voltage nanoelectroporation system to achieve cell detection, intracellular drug delivery, and sensing of intracellular enzymes. Both theoretical simulations and experimental results revealed that the conductive nanostraws in direct contact with cells could induce high-efficiency cell electroporation at relatively low voltage (∼5 V). Efficient delivery of reagents into live cells with spatial control and repeated extraction of intracellular enzymes (e.g., caspase-3) for temporal monitoring from the same set of cells were demonstrated. This work not only pioneers a new avenue for universal production of conductive nanostraws on a large scale but also presents great potential for developing nanodevices to achieve a variety of biomedical applications including cell re-engineering, cell-based therapy, and signaling pathway monitoring.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Galvanoplastia/métodos , Desenho de Equipamento , Nanoestruturas/química , Técnicas Biossensoriais/instrumentação , Sobrevivência Celular , Células/química , Células/enzimologia , Condutividade Elétrica , Enzimas/análise , Células HeLa , Humanos , Nanotecnologia , Platina/química
4.
Biosens Bioelectron ; 146: 111741, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31586765

RESUMO

The design and fabrication of high visible-light activated photoelectrode are essential to precisely detect biomolecule in biological system. Herein, an ultrasensitive photoelectrochemical (PEC) aptasensor for specific recognition of adenosine is established based on carbon dots sensitized-amorphous molybdenum sulfide (a-MoSx/CDs) photoanode and dual amplification strategy. The heterostructured photoanode achieved by sequential electrodeposition reveals significantly boosted photocurrent with good stability and repeatability under visible light illumination, giving the credit to highly activated visible light absorption, uniform coverage and good electric contact to the underlying substrate, as well as the energy-band alignment between the two components. By stepwisely immobilizing complementary DNA probe (NH2-DNA) and adenosine aptamer (Apt), followed by methylene blue (MB) binding with the guanine base on Apt, a dual amplified self-powered PEC aptasensor for adenosine detection is constructed. Based on the co-sensitization effect of CDs and MB, ultrasensitive and high-affinitive determination of adenosine is realized over the concentration range of 0.01 nM-1000 nM at 0 V (vs. SCE), with satisfactory stability and reproducibility. The detection limit is as low as 3.3 pM, demonstrating a performance even surpassing most of the sensors reported so far. The prospective application of the co-sensitized a-MoSx photoanode for ultrasensitive aptasensing is highlighted in this work.


Assuntos
Adenosina/sangue , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Dissulfetos/química , Molibdênio/química , Pontos Quânticos/química , Adenosina/análise , Técnicas Eletroquímicas/métodos , Galvanoplastia/métodos , Humanos , Luz , Limite de Detecção
5.
IET Nanobiotechnol ; 13(8): 829-833, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31625523

RESUMO

Human epidermal growth factor receptor 2 (HER-2) is overexpressed in 20-30% of human breast cancers, associated with poor prognosis and tumour aggression. The aim of this study was the production of trastuzumab-targeted Ecoflex nanoparticles (NPs) loaded with docetaxel and in vitro evaluation of their cytotoxicity and cellular uptake. The NPs were manufactured by electrospraying and characterised regarding size, zeta potential, drug loading, and release behaviour. Then their cytotoxicity was evaluated by MTT assay against an HER-2-positive cell line, BT-474, and an HER-2-negative cell line, MDA-MB-468. The cellular uptake was studied by flow cytometry and fluorescent microscope. The particle size of NPs was in an appropriate range, with relatively high drug entrapment and acceptable release efficiency. The results showed no cytotoxicity for the polymer, but the significant increment of cytotoxicity was observed by treatment with docetaxel-loaded NPs in both HER-2-positive and HER-2-negative cell lines, in comparison with the free drug. The trastuzumab-targeted NPs also significantly enhanced cytotoxicity against BT-474 cells, compared with non-targeted NPs.


Assuntos
Materiais Revestidos Biocompatíveis/síntese química , Docetaxel/administração & dosagem , Portadores de Fármacos/síntese química , Galvanoplastia/métodos , Nanopartículas/química , Poliésteres/química , Trastuzumab/química , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/uso terapêutico , Docetaxel/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Nanoconjugados/química , Nanoconjugados/uso terapêutico , Nanopartículas/uso terapêutico , Tamanho da Partícula , Poliésteres/síntese química , Poliésteres/uso terapêutico
6.
Mater Sci Eng C Mater Biol Appl ; 104: 109880, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500020

RESUMO

The direct electron transfer and enzyme catalytic activity were investigated in electrochemical biosensor based on glucose oxidase (GOx) and electrochemical reduced graphene oxide-poly-(l-lysine) (ERGO-PLL) hybrid composite film embedded in a biocompatible matrix of Nafion. The ERGO-PLL was fabricated onto glassy carbon electrode (GCE) through one step electrodeposition of RGO incorporating PLL from graphene oxide-l-lysine aqueous dispersion. The fabrication process of Nafion/GOx/ERGO-PLL/GCE has been characterized by cyclic voltammetry and electrochemical impedance spectroscopy, and the surface morphology of modified electrodes were characterized by scanning electron microscopy. A pair of well-defined redox peaks with formal potential and peak separation of -0.461 V and 30 mV were observed at scan rate of 50 mV s-1, the electron transfer rate constant was calculated to be 18.7 s-1, demonstrated that direct electron transfer between immobilized GOx with ERGO-PLL and GCE was achieved. Moreover, the fabricated enzyme biosensor exhibited excellent electrocatalytic activity for determination of glucose in O2-free PBS (7.40) with linear voltammetric response from 0.005 to 9.0 mmol L-1, and detection limits (S/N = 3) of 2.0 µmol L-1. This work indicates that ERGO-PLL based modified electrode is superior to that of graphene based, and could be applied in biosensors, bioelectronics and electrocatalysis, etc.


Assuntos
Glucose Oxidase/química , Glucose/química , Grafite/química , Lisina/química , Técnicas Biossensoriais/métodos , Carbono/química , Catálise , Técnicas Eletroquímicas/métodos , Eletroquímica/métodos , Eletrodos , Galvanoplastia/métodos , Enzimas Imobilizadas/química , Concentração de Íons de Hidrogênio , Nanocompostos/química , Oxirredução , Polimerização
7.
Biosens Bioelectron ; 142: 111577, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31430613

RESUMO

A novel nonsemiconductor photoelectrochemical biosensor was first constructed using the unique plasmonic AuNi nanodendrite arrays. The AuNi nanodendrite arrays were rapidly prepared by a one-step electrodeposition method using the porous anodic aluminum templates. Owing to its hierarchical structure with abundant active sites, the synergistic catalytic of Au and Ni can be better exploited. These plasmonic AuNi nanodendrite arrays display exceptional photoelectrocatalytic activities for glucose oxidation and hydrogen peroxide reduction reaction under visible light illumination. Specifically, the detection sensitivity for glucose (3.7277 mA mM-1 cm-2) under illumination is about 3.3 folds improvement than in the dark (1.1287 mA mM-1 cm-2), together with high accuracy and low detection limit of 3 µM. The markedly enhanced performance of AuNi nanodendrite arrays can be attributed to its hierarchical structure with abundant active sites and plasmonic effect of Au with strong absorption band in visible region. Such a newly developed method via the facile and low-cost route is of great significance in designing the plasmon-aided photoelectrochemical biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Glicemia/análise , Ouro/química , Peróxido de Hidrogênio/análise , Nanoestruturas/química , Níquel/química , Técnicas Eletroquímicas/métodos , Galvanoplastia/métodos , Humanos , Limite de Detecção , Masculino , Nanoestruturas/ultraestrutura , Semicondutores
8.
J Mater Sci Mater Med ; 30(9): 99, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455977

RESUMO

Adipose-derived mesenchymal stem cells (ASCs) accelerate the osteointegration of bone grafts and improve the efficiency in the formation of uniform bone tissue, providing a practical and clinically attractive approach in bone tissue regeneration. In this work, the effect of nanofibrous biomimetic matrices composed of poly(ε-caprolactone) (PCL), nanometric hydroxyapatite (nHA) particles and 14-3-3 protein isoform epsilon on the initial stages of human ASCs (hASCs) osteogenic differentiation was investigated. The cells were characterized by flow cytometry and induction to differentiation to adipogenic and osteogenic lineages. The isolated hASCs were induced to differentiate to osteoblasts over all scaffolds, and adhesion and viability of the hASCs were found to be similar. However, the activity of alkaline phosphatase (ALP) as early osteogenic marker in the PCL-nHA/protein scaffold was four times higher than in PCL-nHA and more than five times than the measured in neat PCL.


Assuntos
Proteínas 14-3-3 , Durapatita , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Poliésteres , Tecidos Suporte/química , Proteínas 14-3-3/química , Proteínas 14-3-3/farmacologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Durapatita/química , Durapatita/farmacologia , Galvanoplastia/métodos , Humanos , Teste de Materiais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Nanofibras/química , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Osteogênese/fisiologia , Poliésteres/química , Poliésteres/farmacologia , Gordura Subcutânea Abdominal/citologia , Propriedades de Superfície/efeitos dos fármacos , Engenharia Tecidual/métodos
9.
Chemosphere ; 236: 124330, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31319309

RESUMO

Shear-induced dissociation coupling with ultrafiltration (SID-UF) is an efficient and environment-friendly technology for the separation of heavy metal ions. In this paper, SID-UF was successfully employed for the selective recovery of nickel, zinc and copper from electroplating effluent using poly (acrylic acid) sodium (PAAS) and copolymer of maleic acid and acrylic acid (PMA) as complexants, respectively. The effects of the pH, mass ratio of polymer to metal ions (P/M) and the rotating speed on the metals removal efficiency are discussed in detail. The shear stabilities of the polymer-metal complexes were explored and the complexes critical shear rates (γc) were calculated. The results show that the order of the shear stabilities of PAA-metal complex is PAA-Zn > PAA-Cu > PAA-Ni, and that of PMA-metal complex is PMA-Cu > PMA-Ni > PMA-Zn. In addition, the construction of the stable structures of complexes and the calculation of the energies of the frontier molecular orbital by density functional theory method further predict and confirm the shear stabilities of the polymer-metal complexes.


Assuntos
Galvanoplastia/métodos , Metais Pesados/química , Ultrafiltração/métodos
10.
Int J Nanomedicine ; 14: 3929-3941, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213809

RESUMO

Introduction: Hierarchical nanofibrous scaffolds are emerging as a promising bone repair material due to their high cell adhesion activity and nutrient permeability. However, the existing method for hierarchical nanofibrous scaffolds fabrication is complicated and not perfectly suitable for further biomedical application in view of both structure and function. In this study, we constructed a hierarchical nanofibrous poly (l-lactic acid)/poly(ε-caprolactone) (PLLA/PCL) scaffold and further evaluated its bone healing ability. Methods: The hierarchical PLLA/PCL nanofibrous scaffold (PLLA/PCL) was prepared by one-pot TIPS and then rapidly mineralized at room temperature by an electrochemical deposition technique. After electrode-positioning at 2 V for 2 hrs, a scaffold coated with hydroxyapatite (M-PLLA/PCL) could be obtained. Results: The pore size of the M-PLLA/PCL scaffold was hierarchically distributed so as to match the biophysical structure for osteoblast growth. The M-PLLA/PCL scaffold showed better cell proliferation and osteogenesis activity compared to the PLLA/PCL scaffold. Further in vivo bone repair studies indicated that the M-PLLA/PCL scaffold could accelerate defect healing in 12 weeks. Conclusion: The results of this study implied that the as-prepared hydroxyapatite coated hierarchical PLLA/PCL nanofibrous scaffolds could be developed as a promising material for efficient bone tissue repair after carefully tuning the TIPS and electrodeposition parameters.


Assuntos
Regeneração Óssea/fisiologia , Galvanoplastia/métodos , Minerais/química , Nanofibras/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Eletricidade , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/ultraestrutura , Osteogênese/efeitos dos fármacos , Porosidade , Ratos Sprague-Dawley , Crânio/diagnóstico por imagem , Crânio/efeitos dos fármacos , Crânio/patologia , Fatores de Tempo , Engenharia Tecidual/métodos , Microtomografia por Raio-X
11.
Mater Sci Eng C Mater Biol Appl ; 102: 623-633, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147034

RESUMO

The current work deals with a time-dependent study to track the antibacterial action of electrodeposited Cu, Cu-SiC functionally graded coating (FGC) against Escherichia coli NCIM 2931 (Gram-negative) and Bacillus subtilis NCIM 2063 (Gram-positive). After 24 h of incubation, the Cu, Cu-SiC FGC causes 7 Escherichia coli NCIM 2931 and 10 Bacillus subtilis NCIM 2063 log reduction of planktonic cells. The outer membrane permeabilization experiment proves that the intake of excessive Cu ions leads to the damage of bacterial cell membrane followed by lipid degradation. The thiobarbituric acid reactive substances assay reveals that Cu ions released from the surface of Cu, Cu-SiC FGC triggers the oxidative degeneration of phospholipids (most abundant constituent of bacterial cell membrane). This was further cross-verified using atomic absorption spectroscopy. From 0 to 24 h, the bacterial morphology is characterized using transmission electron microscope and scanning electron microscope which shows the cytoplasmic leakage and cell death. The Cu, Cu-SiC FGC also exhibits hydrophobic surface (contact angle of 144°) which prevents the bacterial adherence to the surface and thus, inhibits them to penetrate into its bulk. The observed results of antibacterial and anti-adhesion properties of Cu, Cu-SiC FGC are compared with single-layered metallic Cu and Cu-SiC nanocomposite coatings. Hence, the electrodeposited Cu, Cu-SiC FGC has the potential to serve as an inexpensive touch surface alternative for the healthcare industries.


Assuntos
Membrana Celular/metabolismo , Materiais Revestidos Biocompatíveis/farmacologia , Galvanoplastia/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/ultraestrutura , Aderência Bacteriana/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Cobre/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/ultraestrutura , Íons , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de Tempo
12.
Mater Sci Eng C Mater Biol Appl ; 102: 661-669, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147039

RESUMO

A selective electrochemical sensor based on poly(3,4-ethylenedioxythiophene) (PEDOT) - Prussian blue nanoparticles (PBNPs) for hydrogen peroxide (H2O2) determination was prepared by innovative sinusoidal voltage (SV) method. The successful incorporation of citrate-stabilized PBNPs into PEDOT matrix was confirmed by energy dispersive X-ray analysis (EDX), Raman spectroscopy, UV-Vis spectroelectrochemistry and cyclic voltammetry measurements. The SV preparation method provides a PEDOT-PBNPs coating with rough surface morphology and good electrocatalytic activity toward H2O2 reduction. The amperometric response of PEDOT-PBNPs-based sensor at -50 mV vs. Ag/AgCl is linear within the range of concentrations from 5 µM to 1 mM H2O2 with a detection limit of 1.4 µM H2O2. The proposed Pt/PEDOT-PBNPs sensor displays good repeatability, reproducibility, operational stability as well as good selectivity toward H2O2 determination in the presence of interfering species like dopamine (DA), uric acid (UA), KNO2 glucose (Glu), KNO3 and ascorbic acid (AA), and was successfully applied to H2O2 determination in human blood samples without biofouling.


Assuntos
Técnicas Biossensoriais/métodos , Compostos Bicíclicos Heterocíclicos com Pontes/química , Eletricidade , Galvanoplastia/métodos , Ferrocianetos/química , Peróxido de Hidrogênio/sangue , Nanopartículas/química , Polímeros/química , Espectroscopia Dielétrica , Feminino , Humanos , Pessoa de Meia-Idade , Nanopartículas/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Work ; 63(3): 355-360, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31227679

RESUMO

BACKGROUND: Metal co-exposure of human subjects is an important matter of public health concern. It has been shown that Acetylcholinesterase activity is a suitable biomarker for the neurological risk assessment of some metals. A few studies have reported neurotoxicity risk among humans in co-exposure to chromium and nickel. OBJECTIVE: In this study, AChE activity was assessed in occupational exposure to chromium (VI) and co-exposure to nickel (II) and chromium (VI). METHODS: Air sampling was done in chromium electroplating workshops with the NIOSH 7600 and OSHA ID-121 methods for chromium and nickel assessment. Thirty-two workers from hard chromium plating and 30 from decorative chromium plating were evaluated, while AChE activity was measured by the Elman method. RESULTS: Personal exposure to chromium in 20% of the studied people exceeded the TWA set by ACGIH. Occupational exposure to nickel in 47% of the DCP subjects was found to be higher than TWA. Cholinergic inhibition in plating workers was marked by a decrease in AChE compared to controls. Subjects with chromium (VI) exposure contained significantly higher inhibition of AChE activity (p < 0.001) than workers with co-exposure to nickel (II) and chromium (VI). CONCLUSIONS: The chromium-matched electroplaters have no significant difference in AChE activity. It can be concluded that cholinergic inhibition with chromium (VI) is higher than nickel (II) exposure.


Assuntos
Galvanoplastia/métodos , Exposição Ocupacional/efeitos adversos , Medição de Risco/métodos , Adulto , Cromo/efeitos adversos , Monitoramento Ambiental/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Níquel/efeitos adversos
14.
Nano Lett ; 19(6): 3569-3574, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117749

RESUMO

A novel method to fabricate porous Fe-Ni-Co nanowires directly by electrodepositing into polycarbonate membranes is reported when the electrolyte pH < 0.5. Hydrogen bubbles are used as a dynamic porous template created by operating in electrolytes with very low pH to drive the proton reduction reaction. The electrolyte pH was adjusted with sulfuric acid, and the added sulfate ions are thought to help reduce bubble coalescence, but not detachment at the electrode surface, to facilitate metal deposition within the nanopores. Porous nanowires were obtained when the electrolyte pH was less than 1.0. The average alloy composition was found to be pH sensitive, which shifted from an Fe-rich porous alloy to a Ni-rich porous alloy as the electrolyte pH decreased.


Assuntos
Cobalto/química , Ferro/química , Nanofios/química , Níquel/química , Ligas/química , Galvanoplastia/métodos , Hidrogênio/química , Nanotecnologia/métodos , Nanofios/ultraestrutura , Cimento de Policarboxilato/química , Porosidade
15.
Chem Pharm Bull (Tokyo) ; 67(5): 445-451, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31061369

RESUMO

Electrodeposition is commonly used to deposit ceramic or metal coating on metallic implants. Its utilization in depositing polymer microcapsule coating is currently being explored. However, there is no encapsulation of drug within polymer microcapsules that will enhance its chemical and biological properties. Therefore, in this study, ginseng which is known for its multiple therapeutic effects was encapsulated inside biodegradable poly(lactic-co-glycolic acid) (PLGA) microcapsules to be coated on pre-treated medical grade stainless steel 316L (SS316L) using an electrodeposition technique. Polyaniline (PANI) was incorporated within the microcapsules to drive the formation of microcapsule coating. The electrodeposition was performed at different current densities (1-3 mA) and different deposition times (20-60 s). The chemical composition, morphology and wettability of the microcapsule coatings were characterized through attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and contact angle analyses. The changes of electrolyte colors, before and after the electrodeposition were also observed. The addition of PANI has formed low wettability and uniform microcapsule coatings at 2 mA current density and 40 s deposition time. Reduction in the current density or deposition time caused less attachment of microcapsule coatings with high wettability records. While prolonging either one parameter has led to debris formation and melted microcapsules with non-uniform wettability measurements. The color of electrolytes was also changed from milky white to dark yellow when the current density and deposition time increased. The application of tolerable current density and deposition time is crucial to obtain a uniform microcapsule coating, projecting a controlled release of encapsulated drug.


Assuntos
Compostos de Anilina/química , Materiais Revestidos Biocompatíveis/química , Galvanoplastia/métodos , Panax/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Aço Inoxidável/química , Cápsulas , Composição de Medicamentos/instrumentação , Composição de Medicamentos/métodos , Galvanoplastia/instrumentação , Desenho de Equipamento , Próteses e Implantes
16.
J Vis Exp ; (145)2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30958462

RESUMO

Knowledge of the behavior of cuprous ions (monovalent copper ion: Cu(I)) in a copper sulfate plating bath is important for improving the plating process. We successfully developed a method to quantitatively and easily measure Cu(I) in a plating solution and used it for evaluation of the solution. In this paper, a quantitative absorption spectrum measurement and a time-resolved injection measurement of Cu(I) concentrations by a color reaction are described. This procedure is effective as a method to reproduce and elucidate the phenomenon occurring in the plating bath in the laboratory. First, the formation and accumulation process of Cu(I) in solution by electrolysis of a plating solution is shown. The amount of Cu(I) in the solution is increased by electrolysis at higher current values ​​than the usual plating process. For the determination of Cu(I), BCS (bathocuproinedisulfonic acid, disodium salt), a reagent that selectively reacts with Cu(I), is used. The concentration of Cu(I) can be calculated from the absorbance of the Cu(I)-BCS complex. Next, the time measurement of the color reaction is described. The color reaction curve of Cu(I) and BCS measured by the injection method can be decomposed into an instantaneous component and a delay component. By analysis of these components, the holding structure of Cu(I) can be clarified, and this information is important when predicting the quality of the plating film to be produced. This method is used to facilitate the evaluation of the plating bath in the production line.


Assuntos
Sulfato de Cobre/química , Cobre/análise , Galvanoplastia/métodos , Simulação por Computador , Eletricidade , Eletrólise , Análise Espectral , Fatores de Tempo
17.
Mater Sci Eng C Mater Biol Appl ; 101: 292-305, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029323

RESUMO

A novel implant coating material containing graphene oxide (GO) and collagen (COL), and hydroxyapatite (HA) was fabricated with the aid of tannic acid by electrodeposition. The surface of Ti16Nb alloy was subjected to anodic oxidation, and then HA-GO coating was applied to Ti16Nb surface by cathodic method. Then, COL was deposited on the surface of the HA-GO coating by the biomimetic method. HA, HA-GO, HA-GO-COL coatings on the surface of the Ti16Nb alloy have increased the corrosion resistance by the formation of a barrier layer on the surface. For HA-GO-COL coating, the highest corrosion resistance is obtained due to the compactness and homogeneity of the coating structure. The contact angle of the bare Ti16Nb is approximately 65°, while the contact angle of the coated samples is close to 0°. Herein, the increased surface wettability is important for cell adhesion. The surface roughness of the uncoated Ti16Nb alloy was between 1 and 3 µm, while the surface roughness of the coated surfaces was measured between 20 and 110 µm. The contact between the bone and the implant has been improved. Graphene oxide-containing coatings have improved the antibacterial properties compared to the GO-free coating using S. aureus. The hardness and elastic modulus of the coatings were measured by the nanoindentation test, and the addition of GO and collagen to the HA coating resulted in an increase in strength. The addition of GO to the HA coating reduced the viability of 3 T3 fibroblast cells, whereas the addition of collagen to HA-GO coat increased the cell adhesion and viability.


Assuntos
Ligas/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Colágeno/farmacologia , Durapatita/farmacologia , Galvanoplastia/métodos , Grafite/farmacologia , Compostos de Estanho/química , Células 3T3 , Animais , Corrosão , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Nanotubos/química , Nanotubos/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Compostos de Estanho/farmacologia , Difração de Raios X
18.
Mater Sci Eng C Mater Biol Appl ; 101: 380-386, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029331

RESUMO

An auxiliary electrode electrospinning method is proposed to deposit N-octyl-2-cyanoacrylate (NOCA) medical glue fibrous membrane on kidney for in-situ fast hemostasis. A metal electrode equipped to the spinning needle is used to confine the divergence angle of jet. Compared to the conventional electrospinning method, the fiber deposition area has reduced by 2.5 times, and it can achieve in-situ accurate deposition. Moreover, it reduces both the external dimension and over-reliance on electricity, which is superior to previous air-flow assisted electrospinning method. In addition, in situ accurate deposition of NOCA on the kidney exhibits fast hemostasis within 10 s, confirming that this auxiliary electrode method can be applied in outdoors for fast hemostasis. Further pathological studies indicate that this auxiliary electrode method can reduce the inflammatory response of tissues due to the better accurate deposition. This portable hand-held device with the auxiliary electrode method may have potential application in fast hemostasis for outdoors due to its accurate deposition and portability characteristics.


Assuntos
Adesivos/farmacologia , Galvanoplastia/métodos , Hemostasia/efeitos dos fármacos , Rim/efeitos dos fármacos , Animais , Contagem de Células Sanguíneas , Estimulação Elétrica , Eletrodos , Rim/patologia , Masculino , Ratos Sprague-Dawley , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos
19.
Mater Sci Eng C Mater Biol Appl ; 100: 475-484, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30948083

RESUMO

Calcium phosphate (CaP) coatings were electrochemically deposited on titanium substrates. By increasing the electrodeposition time (from 1 to 30 min), the coating thickness increases but also the surface morphology of the CaP coatings is greatly affected going from smooth to plate-like, featuring elongated plates, ribbon-like and finally sharp needle structures. Micro-stretch tests reveal that, regardless of the coating morphology and thickness, the electrodeposited CaP coatings have strong adhesion with the titanium substrates and their failure mode is cohesive failure. The effects of different morphologies on cellular behavior such as adhesion, viability, proliferation, and osteogenic gene expression were studied. The surface morphology of CaP coatings has a remarkable effect on cell attachment, proliferation, and viability. A smooth surface results in better adhesion of the cells, whereas the presence of sharp needles and ribbons on rough surfaces restricts cell adhesion and consequently cell proliferation and viability. The improved cell adhesion and viability on the smoother surface can be attributed to the higher contact area between the cell and the coating, while the needle-like morphology inflicts damage to the cells by physically disrupting the cell wall. There is no significant difference in the level of osteoblast gene expression when osteosarcoma cells are cultured on coatings with different morphologies. Our study provides crucial insights into the optimum electrodeposition procedures for CaP coating formation leading to both good cell-material interaction and sufficient mechanical properties. This can be achieved with relatively thin coatings produced by short electrodeposition times.


Assuntos
Fosfatos de Cálcio/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Galvanoplastia/métodos , Teste de Materiais , Fenômenos Mecânicos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fricção , Humanos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Propriedades de Superfície
20.
J Mater Sci Mater Med ; 30(4): 42, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30919082

RESUMO

Biodegradable polymers such as polycaprolactone (PCL) are increasingly used for electrospinning substrates for tissue engineering. These materials offer great advantages such as biocompatibility and good mechanical properties. However, in order to be approved for human implantation they have to be sterilized. The impact of commonly used irradiation sterilization methods on electrospun PCL fiber mats was investigated systematically. Electron beam (ß-irradiation), gamma and X-ray irradiation with two different doses (25 and 33 kGy) were investigated. To determine the impact on the fiber mats, mechanical, chemical, thermal properties and crystallinity were investigated. Irradiation resulted in a significant decrease in molecular weight. At the same time, crystallinity of fiber mats increased significantly. However, the mechanical properties did not change significantly upon irradiation, mostly likely because effects of a lower molecular weight were balanced with the higher degree of crystallinity. The irradiation effects were dose dependent, a higher irradiation dose led to stronger changes. Gamma irradiation seemed to be the least suited method, while electron beams (ß irradiation) had a lower impact. Therefore, ß irradiation is recommended as sterilization method for electrospun PCL fiber mats.


Assuntos
Desinfecção/métodos , Membranas Artificiais , Nanofibras/química , Nanofibras/efeitos da radiação , Poliésteres/química , Tecidos Suporte , Elétrons , Galvanoplastia/métodos , Raios gama , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Poliésteres/efeitos da radiação , Polímeros/química , Polímeros/efeitos da radiação , Esterilização/métodos , Estresse Mecânico , Propriedades de Superfície , Engenharia Tecidual/métodos , Tecidos Suporte/química , Raios X
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