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1.
Dental Press J Orthod ; 25(4): 51-58, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32965387

RESUMO

OBJECTIVE: To investigate the effect of ZnO nanocoating on mechanical properties of NiTi orthodontic wires and antibacterial activity. METHODS: 0.016 x 0.022-in NiTi orthodontic wires were coated with ZnO nanoparticles using an electrochemical deposition method with three electrodes system in 0.1M Zn(NO3)2. Mechanical properties and frictional resistance of the coated wires were investigated using an universal testing machine. Antibacterial effect of ZnO coating was also investigated. RESULTS: A stable adhered ZnO nanocoating on NiTi wires was obtained. The coated wires have a significant antibacterial activity against S. aureus, S. pyogens and E. coli, and a reduction of frictional forces by 34%. CONCLUSION: ZnO nanocoating may improve the antibacterial effects of NiTi wires and reduce the frictional resistance. Coating may be implanted in orthodontic practice for faster and safer treatment.


Assuntos
Óxido de Zinco/farmacologia , Antibacterianos/farmacologia , Ligas Dentárias , Escherichia coli , Teste de Materiais , Níquel , Fios Ortodônticos , Staphylococcus aureus , Propriedades de Superfície , Titânio/farmacologia , Zinco
2.
Chemosphere ; 254: 126794, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957267

RESUMO

Present study carried out pot experiments and evaluated effects of single and binary mixture of nanoparticles (exposed via sludge as soil conditioner) on spinach plant. Exposure of Ag2O nanoparticles (NPs) (1 and 10 mg/kg soil-sludge) did not show significant reduction in plant as compared to control. On the other hand, TiO2 NPs (exposed as single and in binary mixture) resulted in significant increase in root length (29% and 37%) and fresh weight (60% and 48%) at highest exposure concentration. Total chlorophyll content decreased for Ag2O and binary mixture (7% and 4%, respectively) and increased for TiO2 (5%) at 10 mg/kg soil-sludge. The toxic interaction between Ag2O and TiO2 NPs was additive at both exposure concentrations. Ag2O NPs had higher tendency of root surface adsorption than TiO2 NPs. Metal content in spinach leaves at highest exposure concentration was Ag: 2.6 ± 0.55 mg/g plant biomass(for Ag2O NPs) and 1.02 ± 0.32 mg/g plant biomass (for Ag2O + TiO2 NPs) and for Ti: 1.12 ± 0.78 (for TiO2 NPs) mg/g plant biomass and 0.58 ± 0.41 mg/g (for Ag2O + TiO2 NPs). The inadvertent ingestion of NPs- contaminated spinach resulted in projected daily intake (DI) of Ag and Ti for different age-mass classes (child to adult) exceeding the oral reference dose for toxicity during oral ingestion. In conclusion, we report no acute toxicity of single and binary mixture of NPs to spinach but significant accumulation of Ag and Ti metals in spinach leaves. There are high chances that ingestion of spinach grown in such environment might lead to human health risks.


Assuntos
Nanopartículas/toxicidade , Poluentes do Solo/toxicidade , Spinacia oleracea/efeitos dos fármacos , Biomassa , Clorofila , Humanos , Nanopartículas Metálicas/toxicidade , Metais/toxicidade , Nanopartículas/análise , Folhas de Planta/química , Esgotos , Solo , Poluentes do Solo/análise , Spinacia oleracea/crescimento & desenvolvimento , Titânio/farmacologia
3.
Int J Nanomedicine ; 15: 4755-4762, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753864

RESUMO

Aim: This study was conducted to evaluate the effects of three nanoparticle solutions used as dentin pretreatments on the microshear bond strength (µSBS) of a conventional glass ionomer cement (GIC) to dentin. Materials and Methods: Ninety intact human molars were used after sectioning their occlusal surfaces to expose flat dentin surfaces. The specimens were randomly assigned to nine groups (n = 10). Group A was the control group (without using the cavity disinfectant). In groups B, C, D, and E, the prepared dentin surfaces were treated with 1 cc 2% chlorhexidine (CHX), 0.1% silver nanoparticle (SNP), 0.1% titanium dioxide nanoparticle (TNP), and 0.1% zinc oxide nanoparticle (ZNP) solutions for 1 minute, respectively, before applying the conditioner. CHX, SNPs, TNPs, and ZNPs were applied for 1 minute after applying the conditioner in groups F, G, H, and I, respectively. The specimens were restored with a conventional GIC and underwent µSBS testing after 24 hours. The data were analyzed using the one-way analysis of variance and Tukey's test (p=0.05). Results: The applications of the nanoparticles (SNP, TNP, and ZNP) after the conditioner were associated with significantly greater µSBS values compared to that of the control group (p values < 0.05). Significantly higher µSBS values were observed when TNP or ZNP was applied after the conditioner compared to their applications before the conditioner (p values < 0.05). The highest µSBS values were observed when TNP was applied after the conditioner. Conclusion: Dentin pretreatment with the nanoparticles after applying the conditioner enhanced the bond strength of the GIC to dentin compared with the control group. The best results were obtained for the TNPs applied after the conditioner.


Assuntos
Colagem Dentária , Dentina/efeitos dos fármacos , Cimentos de Ionômeros de Vidro/farmacologia , Nanopartículas Metálicas/química , Prata/farmacologia , Titânio/farmacologia , Óxido de Zinco/farmacologia , Clorexidina/farmacologia , Cimentos de Ionômeros de Vidro/química , Humanos , Teste de Materiais , Propriedades de Superfície
4.
PLoS One ; 15(8): e0235355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817671

RESUMO

The Arbuscular mycorrhizal fungi (AMF) (Funneliformis mosseae), are the most widely distributed symbiont assisting plants to overcome counteractive environmental conditions. In order to improve the sustainability and the activity of AMF, the use of nanotechnology was important. The main objective of this study was to investigate the effect of titanium dioxide nanoparticles (TiO2NPs) on the activity of AMF in common bean roots as well as its activity under salinity stress using morphological and molecular methods. The activity of AMF colonization has increased in the presence of TiO2NPs especially for arbuscule activity (A%), which increased three times with the presence of TiO2NPs. The improvement rate of Funneliformis mosseae on plant growth increased from 180% to 224% of control at the lowest level of salinity and increased from 48% to 130% at higher salinity level, respectively. The AMF dependencies for plant dry biomass increased in the presence of TiO2NPs from 277% in the absence of salinity to 465 and 883% % at low and high salinity levels, respectively. The presence of AMF co-inoculated with TiO2NPs resulted in increasing the salinity tolerance of plants at all levels and reached 110% at salinity level of 100 mM NaCl. Quantitative colonization methods showed that the molecular intensity ratio and the relative density of paired inocula AMF Nest (NS) or chitin synthases gene (Chs) with TiO2NPs were higher significantly P.>0.05 than single inoculants of AMF gene in roots under the presence or the absence of salinity by about two folds and about 40%. Hence, the positive effect of TiO2NPs was confined to its effect on AMF not on bean plants itself.


Assuntos
Ascomicetos/patogenicidade , Nanopartículas Metálicas/química , Phaseolus/microbiologia , Tolerância ao Sal , Ascomicetos/efeitos dos fármacos , Ascomicetos/metabolismo , Quitina Sintase/genética , Quitina Sintase/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Nanopartículas Metálicas/microbiologia , Phaseolus/metabolismo , Simbiose , Titânio/química , Titânio/farmacologia
5.
Int J Nanomedicine ; 15: 4171-4189, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606671

RESUMO

Background: Angiogenic and osteogenic activities are two major problems with biomedical titanium (Ti) and other orthopedic implants used to repair large bone defects. Purpose: The aim of this study is to prepare hydroxyapatite (HA) coatings on the surface of Ti by using electrochemical deposition (ED), and to evaluate the effects of nanotopography and silicon (Si) doping on the angiogenic and osteogenic activities of the coating in vitro. Materials and Methods: HA coating and Si-doped HA (HS) coatings with varying nanotopographies were fabricated using two ED modes, ie, the pulsive current (PC) and cyclic voltammetry (CV) methods. The coatings were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), and atomic force microscopy (AFM), and their in vitro bioactivity and protein adsorption were assessed. Using MC3T3-E1 pre-osteoblasts and HUVECs as cell models, the osteogenic and angiogenic capabilities of the coatings were evaluated through in vitro cellular experiments. Results: By controlling Si content in ~0.8 wt.%, the coatings resulting from the PC mode (HA-PC and HS-PC) and CV mode (HA-CV and HS-CV) had nanosheet and nanorod topographies, respectively. At lower crystallinity, higher ionic dissolution, smaller contact angle, higher surface roughness, and more negative zeta potential, the HS and PC samples exhibited quicker apatite deposition and higher BSA adsorption capacity. The in vitro cell study showed that Si doping was more favorable for enhancing the viability of the MC3T3-E1 cells, but nanosheet coating increased the area for cell spreading. Of the four coatings, HS-PC with Si doping and nanosheet topography exhibited the best effect in terms of up-regulating the expressions of the osteogenic genes (ALP, Col-I, OSX, OPN and OCN) in the MC3T3-E1 cells. Moreover, all leach liquors of the surface-coated Ti disks promoted the growth of the HUVECs, and the HS samples played a more significant role in promoting cell migration and tube formation than the HA samples. Of the four leach liquors, only the two HS samples up-regulated NO content and expressions of the angiogenesis-related genes (VEGF, bFGF and eNOS) in the HUVECs, and the HS-PC yielded a better effect. Conclusion: The results show that Si doping while regulating the topography of the coating can help enhance the bone regeneration and vascularization of HA-coated Ti implants.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Nanopartículas/química , Osteogênese , Próteses e Implantes , Silício/química , Titânio/farmacologia , Adsorção , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Camundongos , Nanopartículas/ultraestrutura , Nanotubos/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Soroalbumina Bovina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
6.
Int J Nanomedicine ; 15: 3393-3404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523339

RESUMO

Introduction: The efficacy of several antimicrobial agents has been hindered due to the increasing frequency of multidrug-resistant (MDR) Pseudomonas aeruginosa strains. So, the need for new antibacterial drugs or drug combinations is urgent. Recently, desirable antibacterial effects were reported for many metals nanoparticles such as TiO2 nanoparticles (TDNs). Purpose: This study aims to investigate the prevalence of MDR P. aeruginosa and assess the efficiency of TDN in the treatment of MDR P. aeruginosa-associated infections. Materials and Methods: The synthesis of TDN by the sol-gel method was carried out. Particle size measurements and morphology were done using dynamic light scattering (DLS) and high-resolution transmission electron microscopy (HR-TEM). To investigate the physical and chemical changes of drugs due to the combination, the tested drugs, both alone and in combination with TDN, were subjected to differential scanning calorimetry (DSC), infrared (IR) spectroscopy, and X-ray diffraction studies. Antimicrobial susceptibility was detected by agar disc-diffusion assay. The minimum inhibitory concentration (MIC) of TDN and the tested antibiotics were assessed by the agar dilution method. Checkerboard analysis was performed to determine the combined effect of TDN and the tested antibiotics against 25 MDR P. aeruginosa strains. Results: TDNs were prepared with an average particle size of 64.77 ± 0.14 nm with an accepted polydispersity index (PDI) value of 0.274 ± 0.004. TEM showed that the particles were shaped into irregular spheres. Twenty-five P. aeruginosa isolates that were absolutely resistant to cefepime (100%), highly resistant to ceftriaxone (96%), amikacin (80%), and ciprofloxacin (76%) were selected. Superior antibacterial activity of TDN was observed against the selected 25 MDR P. aeruginosa isolates. The combination of TDN and cefepime were found to show synergistic activity against all tested isolates followed by ceftriaxone (96%), amikacin (88%), and ciprofloxacin (80%). Conclusion: Using TDN in combination with antibiotics can help in the treatment of MDR P. aeruginosa-associated infections. So, preparation of topical pharmaceutical dosage forms containing a combination of these antibiotics and TDN can be useful against MDR P. aeruginosa.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Nanopartículas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Titânio/farmacologia , Antibacterianos/uso terapêutico , Calorimetria , Ciprofloxacino/farmacologia , Ciprofloxacino/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Tamanho da Partícula , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
7.
Int J Nanomedicine ; 15: 3523-3537, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547011

RESUMO

Background: Patients with diabetes mellitus (DM) have a higher failure rate of dental implant treatments. However, whether titanium (Ti) implants with TiO2 nanotubes (TNT) surface can retain their biocompatibility and osteogenetic ability under DM conditions has not been investigated; in addition, their behavior in DM conditions is not well characterized. Materials and Methods: Pure Ti discs were surface treated into the polishing (mechanically polished, MP), sandblasted and acid-etched (SLA), and TNT groups. Scanning electron microscopy was used to examine the surface morphology. The cell adhesion and proliferation ability on different modified Ti surfaces at various glucose concentrations (5.5, 11, 16.5, and 22 mM) was detected by the CCK-8 assay. The osteogenetic ability on different modified Ti surfaces under high-glucose conditions was evaluated by alkaline phosphatase (ALP), osteopontin (OPN) immunofluorescence, Western blot, and Alizarin Red staining in vitro. Detection of cell apoptosis and intracellular reactive oxygen species (ROS) was undertaken both before and after N-acetylcysteine (NAC) treatment to assess the oxidative stress associated with different modified Ti surfaces under high-glucose conditions. An in vivo study was conducted in DM rats with different modified Ti femoral implants. The osteogenetic ability of different modified Ti implants in DM rats was assessed using a micro-CT scan. Results: High-glucose conditions inhibited cell adhesion, proliferation, and osteogenetic ability of different modified Ti surfaces. High-glucose conditions induced higher apoptosis rate and intracellular ROS level on different modified Ti surfaces; these effects were alleviated by NAC. Compared with the SLA surface, the TNT surface alleviated the osteogenetic inhibition induced by high-glucose states by reversing the overproduction of ROS in vitro. In the in vivo experiment, micro-CT scan analysis further confirmed the best osteogenetic ability of TNT surface in rats with DM. Conclusion: TNT surface modification alleviates osteogenetic inhibition induced by DM. It may provide a more favorable Ti implant surface for patients with DM.


Assuntos
Diabetes Mellitus/patologia , Nanotubos/química , Osteogênese/efeitos dos fármacos , Titânio/farmacologia , Fosfatase Alcalina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Glucose/toxicidade , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Osteopontina/metabolismo , Próteses e Implantes , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Propriedades de Superfície
8.
Aquat Toxicol ; 224: 105502, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32480176

RESUMO

The present study examined the effect of titanium dioxide nanoparticles (nanoTiO2) and mercury (Hg) compounds on the green alga, Chlamydomonas reinhardtii. Mixtures containing nanoTiO2 of different primary sizes (5 nm, 15 nm and 20 nm), inorganic Hg (IHg) or monomethyl Hg (CH3Hg+, MeHg) were studied and compared with individual treatments. Oxidative stress and membrane damage were examined. Stability of nanoTiO2 materials in terms of hydrodynamic size and surface charge as well as Hg adsorption on different nanoTiO2 materials were characterized. The uptake of Hg compounds in the absence and presence of nanoTiO2 was also quantified. Results show that increasing concentrations of nanoTiO2 with different primary size diminished oxidative stress and membrane damage induced by high concentrations of IHg or MeHg, due to the adsorption of Hg on the nanoTiO2 aggregates and consequent decrease of cellular Hg concentrations. The observed alleviation effect of nanoTiO2 materials on Hg biouptake and toxicity was more pronounced for the materials with smaller primary size. IHg adsorbed onto the nanoTiO2 materials to a higher extent than MeHg. The present study highlights that the effects of contaminants are modulated by the co-existing engineered nanomaterials; therefore, it is essential to get a better understanding of their combined effect in the environment.


Assuntos
Chlamydomonas reinhardtii/efeitos dos fármacos , Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Nanopartículas/química , Titânio/farmacologia , Poluentes Químicos da Água/toxicidade , Adsorção , Chlamydomonas reinhardtii/metabolismo , Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Propriedades de Superfície , Titânio/química , Poluentes Químicos da Água/metabolismo
9.
Int J Food Microbiol ; 331: 108763, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32574819

RESUMO

Using titanium teraisopropoxide (TTIP) as the hydrolysis material, titanium dioxide (TiO2) (6.3-11.1 nm) nanoparticles were synthesized via the sol-gel method and reinforced into poly lactic acid (PLA)/TiO2 nanocomposite films by casting. The effect of increasing amounts of TiO2 on the structure and properties of PLA/TiO2 nanocomposite films were evaluated. These results indicated that self-aggregation of TiO2 nanoparticles in PLA films could be avoided via sol-gel and casting processes. The presence of TiO2 significantly improved the tensile strength and thermal stability of films. The PLA/TiO2 (0.6 wt%) film exhibited the highest photocatalytic activity efficiency under UV irradiation and displayed high antibacterial activities with optimal inhibition zones of Staphylococcus aureus, followed by Escherichia dispersibility of TiO2 in films were responsible for those improvements. This study suggests that PLA/TiO2 nanocomposite films could be a promising antimicrobial alternative material to conventional plastic packages.


Assuntos
Escherichia coli/efeitos dos fármacos , Microbiologia de Alimentos/métodos , Embalagem de Alimentos , Nanocompostos/química , Poliésteres/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Titânio/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Nanocompostos/efeitos da radiação , Nanopartículas/química , Poliésteres/síntese química , Raios Ultravioleta
10.
Arch Microbiol ; 202(7): 1873-1880, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448965

RESUMO

The aim is to evaluate the prooxidant and antimicrobial effects of Fe3O4 and TiO2 nanoparticles and thalicarpine by luminescent and standard microbiological assays. Their effect on the kinetics of free-radical oxidation reactions (at pH 7.4 and pH 8.5) is studied in the following model systems, using activated chemiluminescence: chemical, with Fenton's reagent (H2O2-FeSO4)-for the generation of hydroxyl radicals (.OH); chemical, with oxidant hydrogen peroxide (H2O2); chemical (NAD.H-PhMS), for the generation of superoxide radicals (O2.-). Fe3O4 nanoparticles exhibit highly pronounced antioxidant properties; TiO2 nanoparticles exhibit mild to moderate prooxidant properties at neutral and alkaline conditions. Those properties are tested by the chemiluminescent method for the first time. Thalicarpine and its combination with TiO2 nanoparticles exhibit pronounced antioxidant activities at pH 8.5 which are lost and transformed into well-presented prooxidant effects at pH 7.4. That is a result-supported proof on the observed typical properties of thalicarpine and TiO2, namely antibacterial, organic-preserving and anti-pathogenic activities. The antimicrobial effect is tested on Gram-positive and Gram-negative bacteria: two strains of Escherichia coli, Bacillus cereus 1095 and Staphylococcus aureus. All bacteria are destroyed after the application of TiO2, but not Fe3O4 nanoparticles, showing their antibacterial effect. Thalicarpine, in combination with TiO2, showed even synergetic antibacterial effect.


Assuntos
Aporfinas/farmacologia , Bactérias/efeitos dos fármacos , Nanopartículas , Titânio/farmacologia , Anti-Infecciosos/farmacologia , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/farmacologia , Ferro/química , Oxidantes/farmacologia , Oxirredução , Espécies Reativas de Oxigênio
11.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(4): 253-258, 2020 Apr 09.
Artigo em Chinês | MEDLINE | ID: mdl-32268625

RESUMO

Objective: To study the effects of titania nanotubes with three different diameters on human gingival fibroblast (HGF). Methods: Three groups of specimens were prepared. Titania nanotubes with diameters of 30, 100, and 200 nm were synthesized on titanium surfaces through electrochemical anodization at 10, 30, and 60 V, respectively. Specimens were assigned into the three groups according to the diameter of the titania nanotubes. Pure smooth titanium without any treatment was set as the control group. HGF were seeded on the surface of the samples. The cell morphology on the specimens was observed with immunofluorescence staining after 2 h, the cell adhesion after 2 d and cell proliferation after 1, 3, and 7 d were detected using methyl thiazolyl tetrazolium assay, and the secretion of type Ⅰ collagen after 7 d was determined using enzyme-linked immunosorbent assay (each group has three samples for each experiment). Results: HGF on the control group exhibited an oval shape without noticeable extensions. HGF on titania nanotubes with a diameter of 30 nm and titania nanotubes with a diameter of 100 nm elongated further and were arranged orderly. HGF on titania nanotubes with a diameter of 200 nm were sparsely distributed without noticeable extensions. Titania nanotubes with a diameter of 30 nm and titania nanotubes with a diameter of 100 nm could enhance the cell attachment (0.603±0.021 and 0.773±0.045), and secretion of type Ⅰ collagen [(36.5±9.5) and (47.7±4.5) µg/ml, respectively] compared with the control group whose cell attactment was 0.427±0.057, and secretion of type Ⅰ collagen was (22.2±5.9) µg/ml (P<0.05). Furthermore, titania nanotubes with a diameter of 100 nm showed more cell attchment than titania nanotubes with a diameter of 30 nm did (P<0.05). Ttania nanotubes with a diameter of 200 nm clearly impaired the cell adhesion (0.250±0.046) and secretion of type Ⅰ collagen [(10.1±3.7) µg/ml] compared with the control group (P<0.05). At each time point, titania nanotubes with a diameter of 100 nm showed the highest cell proliferation, and the amount of cell proliferation was significantly higher than that on the titania nanotubes with a diameter of 200 nm and the control group at each time point (P<0.05), and was also significantly higher than that on the titania nanotubes with a diameter of 30 nm at day three (P<0.05). At each time point, titania nanotubes with a diameter of 200 nm showed the lowest cell proliferation, which was significantly lower than that on the control group at each time point (P<0.05), except that there was no significant difference in the amount of cell proliferation between titania nanotubes with a diameter of 200 nm and the control group at day one (P>0.05). Conclusions: Titania nanotubes with a diameter of 100 nm can improve the HGF attachment, proliferation, and secretion of type Ⅰ collagen.


Assuntos
Adesão Celular , Proliferação de Células , Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Nanotubos , Titânio/farmacologia , Colágeno Tipo I/metabolismo , Humanos , Propriedades de Superfície
12.
Chemosphere ; 254: 126821, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32325351

RESUMO

Since MXenes (a new family of two-dimensional materials) were first produced in 2011, they have become very attractive nanomaterials due to their unique properties and the range of potential industrial applications. Numerous recent studies have discussed the environmental applications of different MXenes in adsorption, catalysis, and membranes. Only a limited number of MXene-based membrane studies have been published to date, and most have discussed only specific MXenes (i.e., Ti3C2Tx), a small number of solutes (e.g., dyes and inorganic salts), and laboratory-scale short-term experiments under limited water-quality and operational conditions. In addition, to our knowledge, there has been no review of MXene-membrane studies. It is therefore essential to assess the current status of understanding of the performance of these membranes in liquid separation and water purification. Here, a comprehensive literature review is conducted to summarize the current preparation techniques for MXene-based membranes and their applications, particularly in terms of environmental and industrial applications (e.g., water treatment and organic solvent filtration), and to direct future research by identifying gaps in our present understanding. In particular, this review focuses on several key factors, including the effects of preparation techniques on membrane properties, operational conditions, and compound properties that influence liquid separation during MXene-based membrane filtration.


Assuntos
Membranas Artificiais , Purificação da Água , Adsorção , Nanoestruturas , Titânio/farmacologia , Água
13.
Nat Commun ; 11(1): 1626, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242015

RESUMO

Some insects, such as dragonflies, have evolved nanoprotrusions on their wings that rupture bacteria on contact. This has inspired the design of antibacterial implant surfaces with insect-wing mimetic nanopillars made of synthetic materials. Here, we characterise the physiological and morphological effects of mimetic titanium nanopillars on bacteria. The nanopillars induce deformation and penetration of the Gram-positive and Gram-negative bacterial cell envelope, but do not rupture or lyse bacteria. They can also inhibit bacterial cell division, and trigger production of reactive oxygen species and increased abundance of oxidative stress proteins. Our results indicate that nanopillars' antibacterial activities may be mediated by oxidative stress, and do not necessarily require bacterial lysis.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Membrana Celular/efeitos dos fármacos , Nanoestruturas/química , Estresse Oxidativo/efeitos dos fármacos , Titânio/química , Titânio/farmacologia , Animais , Bactérias/química , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Impedância Elétrica , Odonatos , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície
14.
Int J Nanomedicine ; 15: 1997-2010, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273698

RESUMO

Background: As one of the most widely produced engineered nanomaterials, titanium dioxide nanoparticles (nano-TiO2) are used in biomedicine and healthcare products, and as implant scaffolds; therefore, the toxic mechanism of nano-TiO2 has been extensively investigated with a view to guiding application. Three-dimensional (3D) spheroid models can simplify the complex physiological environment and mimic the in vivo architecture of tissues, which is optimal for the assessment of nano-TiO2 toxicity under ultraviolet A (UVA) irradiation. Methods and Results: In the present study, the toxicity of nano-TiO2 under UVA irradiation was investigated in 3D H22 spheroids cultured in fibrin gels. A significant reduction of approximately 25% in spheroid diameter was observed following treatment with 100 µg/mL nano-TiO2 under UVA irradiation after seven days of culture. Nano-TiO2 under UVA irradiation triggered the initiation of the TGF-ß/Smad signaling pathway, increasing the expression levels of TGF-ß1, Smad3, Cdkn1a, and Cdkn2b at both the mRNA and protein level, which resulted in cell cycle arrest in the G1 phase. In addition, nano-TiO2 under UVA irradiation also triggered the production of reactive oxygen species (ROS), which were shown to be involved in cell cycle regulation and the induction of TGF-ß1 expression. Conclusion: Nano-TiO2 under UVA irradiation induced cell cycle arrest in the G1 phase and the formation of smaller spheroids, which were associated with TGF-ß/Smad signaling pathway activation and ROS generation. These results reveal the toxic mechanism of nano-TiO2 under UVA irradiation, providing the possibility for 3D spheroid models to be used in nanotoxicology studies.


Assuntos
Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Titânio/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Linhagem Celular , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor de Quinase Dependente de Ciclina p15/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/fisiologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos da radiação , Camundongos , Nanopartículas/química , Proteína Smad3/genética , Proteína Smad3/metabolismo , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/efeitos da radiação , Raios Ultravioleta
15.
Int J Nanomedicine ; 15: 1643-1659, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210558

RESUMO

Purpose: Aseptic loosening is a major complication after total joint replacement. Reactive oxygen species generated by local tissue cells and liberated from implant surfaces have been suggested to cause implant failures. Surface modification of titanium (Ti)-based implants with proanthocyanidins (PAC) is a promising approach for the development of anti-oxidant defense mechanism to supplement the mechanical functions of Ti implants. In this study, a controlled PAC release system was fabricated on the surface of Ti substrates using the layer-by-layer (LBL) assembly. Materials and Methods: Polyethyleneimine (PEI) base layer was fabricated to enable layer-by-layer (LBL) deposition of hyaluronic acid/chitosan (HA/CS) multi-layers without or with the PAC. Surface topography and wettability of the fabricated HA/CS-PAC substrates were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR) and contact angle measurement. PAC release profiles were investigated using drug release assays. MC3T3-E1 pre-osteoblast cells were used to assess the osteo-inductive effects of HA/CS-PAC substrates under conditions H2O2-induced oxidative stress in vitro. A rat model of femoral intramedullary implantation evaluated the osseo-integration and osteo-inductive potential of the HA/CS-PAC coated Ti implants in vivo. Results: SEM, AFM, FTIR and contact angle measurements verified the successful fabrication of Ti surfaces with multi-layered HA/CS-PAC coating. Drug release assays revealed controlled and sustained release of PAC over 14 days. In vitro, cell-based assays showed high tolerability and enhanced the osteogenic potential of MC3T3-E1 cells on HA/CS-PAC substrates when under conditions of H2O2-induced oxidative stress. In vivo evaluation of femoral bone 14 days after femoral intramedullary implantation confirmed the enhanced osteo-inductive potential of the HA/CS-PAC coated Ti implants. Conclusion: Multi-layering of HA/CS-PAC coating onto Ti-based surfaces by the LBL deposition significantly enhances implant osseo-integration and promotes osteogenesis under conditions of oxidative stress. This study provides new insights for future applications in the field of joint arthroplasty.


Assuntos
Antioxidantes/farmacologia , Osteogênese/efeitos dos fármacos , Proantocianidinas/farmacologia , Próteses e Implantes , Titânio/farmacologia , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Liberação Controlada de Fármacos , Feminino , Ácido Hialurônico/química , Peróxido de Hidrogênio/farmacologia , Espaço Intracelular/metabolismo , Camundongos , Osseointegração/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Polietilenoimina/química , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Molhabilidade , Microtomografia por Raio-X
16.
Bull Environ Contam Toxicol ; 104(5): 619-626, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32172338

RESUMO

Cadmium contamination of agricultural soils is a serious problem due to its toxic effects on health and yield of crop plants. This study investigates the potential of low-dose nano-TiO2 as soil nanoremediation on Cd toxicity in cowpea plants. To achieve this goal, cowpea seeds were germinated on Cd-spiked soils at 10 mg/kg for 14 days and later augmented with 100 mg nTiO2/kg (nTiO2-50 nm and bTiO2-68 nm, respectively). The results showed that chlorophylls were not altered by nano-TiO2 intervention. Cadmium partitioning in roots and leaves was reduced by the applied nano-TiO2 but significantly higher than control. Ascorbate peroxidase and catalase activities in roots and leaves were promoted by nano-TiO2 intervention compared to control and sole Cd, respectively. However, magnitudes of activity of enzyme activities were higher in nTiO2 compared to bTiO2 treatments. The enhanced enzymes activity led to reduced malonaldehyde content in plant tissues. The study concludes that soil application of nano-TiO2 could be a green alternative to ameliorate soil Cd toxicity in cowpea plants.


Assuntos
Cádmio/metabolismo , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Titânio/farmacologia , Vigna/efeitos dos fármacos , Vigna/enzimologia , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Cádmio/toxicidade , Clorofila/metabolismo , Germinação , Malondialdeído/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/enzimologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Sementes , Solo/química , Poluentes do Solo/metabolismo , Titânio/química , Vigna/crescimento & desenvolvimento
17.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(2): 104-110, 2020 Feb 09.
Artigo em Chinês | MEDLINE | ID: mdl-32074671

RESUMO

Objective: To investigate the antibacterial properties and the osteoblast-compatibility of chlorhexidine (CHX)-modified porous titanium. Methods: Smooth pure titanium specimen with diameter of 10.0 mm and thickness of 1.5 mm treated with alkali heat method were set as control group. Those with covalent conjugation of aminosilane were set as silane group, and those with CHX grafted by glutaraldehyde were set as CHX group. Scanning electron microscope (SEM) was used to observe the surface morphology and element compositions were detected by X-ray photoelectron spectroscopy. Hydrophilicity was analyzed by surface water contact angle test (n=6), while surface amino/imine groups quantification were performed through acid orangeⅡ(n=5) and the CHX was quantified by optical densitometric method (n=5). Live/dead bacterial staining, the morphology of adherent bacteria by SEM, plate counting method and inhibition zone method were executed to evaluate the antibacterial property of the samples. Osteoblast compatibility was evaluated by methyl thiazolyl tetrazolium. Cell-bacterial co-culture was conducted to evaluated the cell viability on the samples under the circumstance with bacteria. Results: After CHX grafting, pores on the titanium surface were decreased, while the atom ratio of C, N, Cl increased and the water contact angle decreased to 37.5°±4.0°. The density of CHX on the surface was (5.07±0.39) µg/cm(2). The results of live/dead bacterial staining and the morphology of adherent bacteria showed that only little dead bacterial (bacterial wall rupture) adherent on the surface of CHX group, which proved that the modified surface could inhibit bacteria adhesion and even destroyed bacteria; the plate counting displayed sporadic colonies and a transparent inhibition zone could be observed, which demonstrated that CHX group could suppress bacteria multiplication from surrounding environment. When incubating for 1 and 3 days, the cell viability of CHX group showed no significant difference from that of control group (P>0.05) ; when incubating for 5 days, the value of cell viability of CHX group was 0.547±0.087, and this was significantly lower than that of the control group (0.751±0.056) (P<0.05), demonstrating a slight inhibition of cell proliferation by CHX. The results of bacteria-cell co-culture for 3 days showed that a mass of bacteria adhered on the surface of the control group while considerable cells adhered on the surface of CHX group and exhibited a good shape. Conclusions: Porous titanium surface grafted by CHX showed an excellent antibacterial properties and allowed cell adhesion in bacterial circumstance, providing immediate implantation options for patients with bad oral health.


Assuntos
Antibacterianos/farmacologia , Clorexidina/farmacologia , Nanoporos , Osteoblastos/efeitos dos fármacos , Titânio/farmacologia , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Células Cultivadas , Humanos , Propriedades de Superfície
18.
Life Sci ; 248: 117466, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32101760

RESUMO

AIMS: Nanoparticles (NPs)-based drugs have been recently introduced to improve the efficacy of current therapeutic strategies for the treatment of cancer; however, the molecular mechanisms by which a NP interacts with cellular systems still need to be delineated. Here, we utilize the autophagic potential of TiO2 NPs for improving chemotherapeutic effects of 5-fluorouracil (5-FU) in human AGS gastric cells. MATERIALS AND METHODS: Cell growth and viability were determined by trypan blue exclusion test and MTT assay, respectively. Vesicular organelles formation was evaluated by acridine orange staining of cells. Cell cycle and apoptosis were monitored by flow cytometry. Reactive oxygen species (ROS) level were measured by DCHF-DA staining. Autophagy was examined by q-PCR and western blotting. Molecular docking was used for studying NP interaction with autophagic proteins. KEY FINDINGS: TiO2 NPs increase ROS production, impair lysosomal function and subsequently block autophagy flux in AGS cells. In addition, the autophagy blockade induced by non-toxic concentrations of TiO2 NPs (1 µg/ml) can promote cytotoxic and apoptotic effects of 5-FU in AGS cells. SIGNIFICANCE: These results confirm the beneficial effects of TiO2 NPs in combination with chemotherapy in in vitro model of gastric cancer, which may pave the way to develop a possible solution to circumvent chemoresistance in cancer.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica , Nanopartículas/química , Titânio/farmacologia , Antimetabólitos Antineoplásicos/química , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagia/genética , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Vesículas Citoplasmáticas/efeitos dos fármacos , Vesículas Citoplasmáticas/metabolismo , Sinergismo Farmacológico , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fluoruracila/química , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Simulação de Acoplamento Molecular , Nanopartículas/ultraestrutura , Conformação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/metabolismo , Proteína Sequestossoma-1/antagonistas & inibidores , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Titânio/química , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
19.
Colloids Surf B Biointerfaces ; 188: 110783, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32004907

RESUMO

The failure of dental implants is usually caused by bacteria infection, poor bioactivity and biocompatibility. It is a common phenomenon clinically. Statherin, a salivary protein, plays a crucial role of mediator between materials and cells/bacteria. However, the conformation of statherin might be changed by the implants in vivo. In this study, we investigated the effects of statherin on the bioactivities, antibacterial abilities and biocompatibilities of the titanium metals and the reaction mechanism. We found that the conformation of statherin was mainly influenced by surface composition, surface structure, surface roughness, surface hydrophilia and Ti-OH groups of materials. Statherin could decrease the cell biocompatibility of the titanium metals including pure titanium (PT), anodic oxidation (AO), sandblasting and etching (SLA) and plasma spraying hydroxyapatite (HA) coating in HGF cell experiments, regulate the bio-mineralization ability of HA coating in SBF, and enhance the antibacterial properties of PT and HA coating. This study revealed that surface properties of materials could change the conformation of statherin, which influenced the bioactivities, antibacterial properties and biocompatibilities of the materials in return.


Assuntos
Antibacterianos/metabolismo , Materiais Revestidos Biocompatíveis/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Titânio/metabolismo , Adsorção , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Implantes Dentários , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Humanos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Conformação Proteica , Proteínas e Peptídeos Salivares/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Propriedades de Superfície , Titânio/química , Titânio/farmacologia
20.
Nanotechnology ; 31(23): 235101, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32097900

RESUMO

Modifications to the compositional, topographical and morphological aspects of bone implants can lead to improved osseointegration, thus increasing the success of bone implant procedures. This study investigates the creation of dual-scale topography on Ti-5Al-5Mo-5V-3Cr (Ti5553), an alloy not presently used in the biomedical field, and compares it to Ti-6Al-4V (Ti64), the most used Ti alloy for bone implants. Dual-scale surface topography was obtained by combining selective laser melting (SLM) and electrochemical anodization, which resulted in micro- and nanoscale surface features, respectively. Ti5553 and Ti64 samples were manufactured by SLM and showed comparable surface topography. Subsequent electrochemical anodization succeeded in forming titania nanotubes (TNTs) on both alloys, with larger nanotubes obtained with Ti5553 at all investigated anodization voltages. At an anodization voltage of 40 V, a minimum time of 20 min was necessary to have nanotube formation on the surface of either alloy, while only nanopores were evident for shorter times. Seeded Saos-2 cells showed ideal interactions with surface-modified structures, with filopodia extending to both surface microparticles characteristic of SLM and to the interior of TNTs. Attractiveness of Ti5553 lies in its lower elastic modulus (E = 72 GPa) compared to Ti64, which should mitigate stress-shielding phenomena in vivo. This, combined with the analogous results obtained in terms of dual-scale surface topography and cell-substrate interaction, could indicate Ti5553 as a promising alternative to the widely-employed Ti64 for bone implant device manufacturing.


Assuntos
Ligas/farmacologia , Osseointegração/efeitos dos fármacos , Titânio/farmacologia , Ligas/síntese química , Ligas/química , Linhagem Celular , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanotubos , Tamanho da Partícula , Próteses e Implantes , Propriedades de Superfície
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