Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan (hyd...Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC), could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes (NT-H). The titanium implant (Ti), nanotubes without polymer loading (NT), and nanotubes loaded with chitosan (NT-C) were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methiciUin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.展开更多
Redox response of trace heavy metals ions(THMIs) has better performance on highly ordered vertically oriented titania nanotube arrays(TNA) annealed in nitrogen. Experimental data showed that different THMIs posses...Redox response of trace heavy metals ions(THMIs) has better performance on highly ordered vertically oriented titania nanotube arrays(TNA) annealed in nitrogen. Experimental data showed that different THMIs possess different reaction peak shapes and charge and discharge capacities. Therefore, the TNA will become an important tool used for environmental protection and facilitating the rapid determination of THMIs. THMIs of 5×10^4 mol/L concentration were measured at a scan rate of 100 mV/s. The analytical utility of TNA is demonstrated in a neutral 0.5 mol/L Na2SO4 solution. The results sufficiently show that titania nanotube arrays electrodes(TNAE) will be used to measure THMIs.展开更多
The rapid in situ inhibition of bacterial contamination and subsequent infection without inducing drug resistance is highly vital for the successful implantation and long-term service of titanium(Ti)-based orthopedic ...The rapid in situ inhibition of bacterial contamination and subsequent infection without inducing drug resistance is highly vital for the successful implantation and long-term service of titanium(Ti)-based orthopedic implants.However,the instability and potential cytotoxicity of current coatings have deterred their clinical practice.In this study,anodic oxidized titania nanotubes(TNT)were modified with antibacterial polyhexamethylene guanidine(PG)with the assistance of 3,4-dihydroxyphenylacetic acid.Interestingly,the prepared TNT-PG coating exhibited superior in vitro antibacterial activity than flat Ti-PG coating and effectively killed typical pathogens such as Escherichia coli and superbug methicillinresistant Staphylococcus aureus with above 4-log reduction(>99.99%killed)in only 5 min.TNT-PG coating also exerted excellent hemocompatibility with red blood cells and nontoxicity toward mouse pre-osteoblasts(MC3 T3-E1)in 1 week of coculture.In addition,the efficient in vivo anti-infective property of this coating was observed in a rat subcutaneous infection model.More importantly,TNT-PG coating improved the expression of alkaline phosphatase and enhanced the extracellular matrix mineralization of pre-osteoblasts,denoting its osteoinductive capacity.This versatile TNT-PG coating with excellent antibacterial activity and biocompatibility could be a promising candidate for advanced orthopedic implant applications.展开更多
Titania nanotubes(TiO2-NTs)are a potential drug vehicle for use in nanomedicine.To this end,a preliminary study of the interaction of a model cell with TiO2-NTs has been carried out.TiO2-NTs were first conjugated with...Titania nanotubes(TiO2-NTs)are a potential drug vehicle for use in nanomedicine.To this end,a preliminary study of the interaction of a model cell with TiO2-NTs has been carried out.TiO2-NTs were first conjugated with a fl uorescent label,fl uorescein isothiocyanate(FITC).FITC-conjugated titania nanotubes(FITC-TiO2-NTs)internalized in mouse neural stem cells(NSCs,line C17.2)can be directly imaged by confocal microscopy.The confocal imaging showed that FITC-TiO2-NTs readily entered into the cells.After co-incubation with cells for 24 h,FITC-TiO2-NTs localized around the cell nucleus without crossing the karyotheca.More interestingly,the nanotubes passed through the karyotheca entering the cell nucleus after co-incubation for 48 h.Atomic force microscopy(AFM)and transmission electron microscopy(TEM)were also employed in tracking the nanotubes in the cell.These results will be of benefit in future studies of TiO2-NTs for use as a drug vehicle,particularly for DNA-targeting drugs.展开更多
Ordered titanium dioxide nanotubes (TiOaNTs) modified with indium tin oxide (ITO) films were obtained via magnetron sputtering, in which ITO plate was used as a target, onto the as-anodized titania support followe...Ordered titanium dioxide nanotubes (TiOaNTs) modified with indium tin oxide (ITO) films were obtained via magnetron sputtering, in which ITO plate was used as a target, onto the as-anodized titania support followed by the calcination process. The morphology of fabricated material with deposited oxide was investigated using scanning electron microscopy. Raman and UV-Vis spectroscopies were utilized to characterize crystalline phase and optical properties of prepared samples, whereas X-ray photoelectron spectroscopy allowed determining the binding energy of present elements. In the case of titanium, three various oxidation states were identified and also the presence of indium and tin was confirmed. The electrochemical test carried out when the sample was exposed to light allows for selection of the most photoactive material. The highest photocurrent was registered when only 5-nm ITO layer was sputtered, and it equals 256 and 133 μA cm^-2 for the electrode material immersed in 0.5 M KOH and K2SO4 electrolytes, respectively, that is accordingly 3.5 and 4.4 times higher than the one observed for pristine titania. Furthermore, ITO-modified titania exhibits excellent photostability upon prolonged illumination that is of key importance for possible application in light-driven processes.展开更多
The TiO 2 nanotube sample was prepared via a NaOH solution in a Teflon vessel at 150℃. The as-prepared nanotubes were then treated with H 2SO 4 solutions. The TiO 2 nanotube has a crystalline structure with open-...The TiO 2 nanotube sample was prepared via a NaOH solution in a Teflon vessel at 150℃. The as-prepared nanotubes were then treated with H 2SO 4 solutions. The TiO 2 nanotube has a crystalline structure with open-ended and multiwall morphologies. The TiO 2 nanotubes before and after surface acid treatment were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and UV-VIS dispersive energy spectrophotometry(DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II in aqueous solutions. It was found that the order of photocatalytic activity was as follows: TiO 2 nanotubes treated with 1.0 mol/L H 2SO 4 solution (TiO 2(1.0M H 2SO 4) nanotubes)>TiO 2 nanotubes treated with 0.2 mol/L H 2SO 4 solution (TiO 2(0.2M H 2SO 4) nanotubes)>TiO 2 nanotubes >TiO 2 powder. This was attributed to the fact that TiO 2 nanotubes treated with H 2SO 4 was composed of smaller particles and had higher specific surface areas. Furthermore, the smaller TiO 2 particles were beneficial to the transfer and separation of photo-generated electrons and holes in the inner of and on the surface of TiO 2 particles and reduced the recombination of photo-generated electrons and holes. Acid treatment was particularly effective for TiO 2 nanotubes, this increase in activity was correlated with the concentration of H 2SO 4 solution.展开更多
Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were pr...Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources (MEVVA, BNU, China) implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows: Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy (at longer wavelength, such as visible light) to be absorbed, which accorded well with the experimental results.展开更多
To improve the photocatalytic efficiency of TiO2nanotubular catalyst,N doped and Pd decorated titania nanotubes was successfully synthesized via anodizing,hydrazine hydrate treatment and photoreduction of Pd ions.The ...To improve the photocatalytic efficiency of TiO2nanotubular catalyst,N doped and Pd decorated titania nanotubes was successfully synthesized via anodizing,hydrazine hydrate treatment and photoreduction of Pd ions.The small Pd nanoparticles were precipitated on TiO2nanotubes through photoreduction of Pd ions,and its distribution is relatively homogeneous.From X-ray photoelectron spectrometry(XPS) result,the N 1s spectrum represents two peaks with binding energy at 399.7 and 400.7 eV,which suggests that the nitrogen elements doped by hydrazine hydrate treatment are located in interstitial sites of the TiO2crystalline structure.For N doped TiO2nanotubes with Pd particles,a high photocurrent was detected due to increase of interface charge carrier separation rate.Moreover,N doped and Pd decorated TiO2nanotubes exhibited much higher dye destruction efficiency and rate constant due to the synergistic effect of the N dopant and the Pd deposition on TiO2nanotubes.展开更多
Mesoporous silica thin film has been widely used in various fields,particularly the medical implant coating for drug delivery.However,some drawbacks remain with the films produced by traditional method(evaporation-ind...Mesoporous silica thin film has been widely used in various fields,particularly the medical implant coating for drug delivery.However,some drawbacks remain with the films produced by traditional method(evaporation-induced self-assembly,EISA),such as the poor permeability caused by their horizontal aligned mesochannels.In this study,the vertical aligned mesoporous silica thin film(VMSTF)is uniformly grown alongside the walls of titania nanotubes array via a biphase stratification growth method,resulting in a hierarchical two-layered nanotubular structure.Due to the exposure of opened mesopores,VMSTF exhibits more appealing performances,including rapid degradation,efficient small-molecular drug(dexamethasone)loading and release,enhanced early adhesion and osteogenic differentiation of MC3T3-E1 cells.This is the first time successfully depositing VMSTF on nanoporous substrate and our findings suggest that the VMSTF may be a promising candidate for bone implant surface coating to obtain bioactive performances.展开更多
基金financially supported by the National Natural Science Foundation of China (No.31271015,81501856)National Key R&D Program (2016YFC1102100)+1 种基金Shanghai Science and Technology Development Fund (13JC1403900,13DZ2294000)Medical Engineering Collaborative Project of Shanghai Jiao Tong University (YG2014ZD01)
文摘Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC), could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes (NT-H). The titanium implant (Ti), nanotubes without polymer loading (NT), and nanotubes loaded with chitosan (NT-C) were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methiciUin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.
文摘Redox response of trace heavy metals ions(THMIs) has better performance on highly ordered vertically oriented titania nanotube arrays(TNA) annealed in nitrogen. Experimental data showed that different THMIs possess different reaction peak shapes and charge and discharge capacities. Therefore, the TNA will become an important tool used for environmental protection and facilitating the rapid determination of THMIs. THMIs of 5×10^4 mol/L concentration were measured at a scan rate of 100 mV/s. The analytical utility of TNA is demonstrated in a neutral 0.5 mol/L Na2SO4 solution. The results sufficiently show that titania nanotube arrays electrodes(TNAE) will be used to measure THMIs.
基金the National Key R&D Program of China(No.2018YFC1105402)the National Natural Science Foundation of China(No.21875189)+1 种基金the Key R&D Program of Jiangsu Province(No.BE201740)the Innovative Talents Promotion Project of Shaanxi Province(No.2019KJXX-064)。
文摘The rapid in situ inhibition of bacterial contamination and subsequent infection without inducing drug resistance is highly vital for the successful implantation and long-term service of titanium(Ti)-based orthopedic implants.However,the instability and potential cytotoxicity of current coatings have deterred their clinical practice.In this study,anodic oxidized titania nanotubes(TNT)were modified with antibacterial polyhexamethylene guanidine(PG)with the assistance of 3,4-dihydroxyphenylacetic acid.Interestingly,the prepared TNT-PG coating exhibited superior in vitro antibacterial activity than flat Ti-PG coating and effectively killed typical pathogens such as Escherichia coli and superbug methicillinresistant Staphylococcus aureus with above 4-log reduction(>99.99%killed)in only 5 min.TNT-PG coating also exerted excellent hemocompatibility with red blood cells and nontoxicity toward mouse pre-osteoblasts(MC3 T3-E1)in 1 week of coculture.In addition,the efficient in vivo anti-infective property of this coating was observed in a rat subcutaneous infection model.More importantly,TNT-PG coating improved the expression of alkaline phosphatase and enhanced the extracellular matrix mineralization of pre-osteoblasts,denoting its osteoinductive capacity.This versatile TNT-PG coating with excellent antibacterial activity and biocompatibility could be a promising candidate for advanced orthopedic implant applications.
基金the Chinese National Programs for Fundamental Research and Development Ministry of Science and Technology(973 Program)(2006CB705604)the National Natural Science Foundation(50578090)the Shuguang Project of the Shanghai Education Committee(07SG46).
文摘Titania nanotubes(TiO2-NTs)are a potential drug vehicle for use in nanomedicine.To this end,a preliminary study of the interaction of a model cell with TiO2-NTs has been carried out.TiO2-NTs were first conjugated with a fl uorescent label,fl uorescein isothiocyanate(FITC).FITC-conjugated titania nanotubes(FITC-TiO2-NTs)internalized in mouse neural stem cells(NSCs,line C17.2)can be directly imaged by confocal microscopy.The confocal imaging showed that FITC-TiO2-NTs readily entered into the cells.After co-incubation with cells for 24 h,FITC-TiO2-NTs localized around the cell nucleus without crossing the karyotheca.More interestingly,the nanotubes passed through the karyotheca entering the cell nucleus after co-incubation for 48 h.Atomic force microscopy(AFM)and transmission electron microscopy(TEM)were also employed in tracking the nanotubes in the cell.These results will be of benefit in future studies of TiO2-NTs for use as a drug vehicle,particularly for DNA-targeting drugs.
基金financially supported by the Polish National Science Centre:Grant No.2012/07/D/ST5/02269supported by the Foundation for Polish Science (FNP)+1 种基金the financial support from Polish National Science Centre under Grant No.2015/17/D/ ST5/02571the financial support from Polish National Science Centre under Grant No.2016/23/N/ST5/02071
文摘Ordered titanium dioxide nanotubes (TiOaNTs) modified with indium tin oxide (ITO) films were obtained via magnetron sputtering, in which ITO plate was used as a target, onto the as-anodized titania support followed by the calcination process. The morphology of fabricated material with deposited oxide was investigated using scanning electron microscopy. Raman and UV-Vis spectroscopies were utilized to characterize crystalline phase and optical properties of prepared samples, whereas X-ray photoelectron spectroscopy allowed determining the binding energy of present elements. In the case of titanium, three various oxidation states were identified and also the presence of indium and tin was confirmed. The electrochemical test carried out when the sample was exposed to light allows for selection of the most photoactive material. The highest photocurrent was registered when only 5-nm ITO layer was sputtered, and it equals 256 and 133 μA cm^-2 for the electrode material immersed in 0.5 M KOH and K2SO4 electrolytes, respectively, that is accordingly 3.5 and 4.4 times higher than the one observed for pristine titania. Furthermore, ITO-modified titania exhibits excellent photostability upon prolonged illumination that is of key importance for possible application in light-driven processes.
文摘The TiO 2 nanotube sample was prepared via a NaOH solution in a Teflon vessel at 150℃. The as-prepared nanotubes were then treated with H 2SO 4 solutions. The TiO 2 nanotube has a crystalline structure with open-ended and multiwall morphologies. The TiO 2 nanotubes before and after surface acid treatment were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and UV-VIS dispersive energy spectrophotometry(DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II in aqueous solutions. It was found that the order of photocatalytic activity was as follows: TiO 2 nanotubes treated with 1.0 mol/L H 2SO 4 solution (TiO 2(1.0M H 2SO 4) nanotubes)>TiO 2 nanotubes treated with 0.2 mol/L H 2SO 4 solution (TiO 2(0.2M H 2SO 4) nanotubes)>TiO 2 nanotubes >TiO 2 powder. This was attributed to the fact that TiO 2 nanotubes treated with H 2SO 4 was composed of smaller particles and had higher specific surface areas. Furthermore, the smaller TiO 2 particles were beneficial to the transfer and separation of photo-generated electrons and holes in the inner of and on the surface of TiO 2 particles and reduced the recombination of photo-generated electrons and holes. Acid treatment was particularly effective for TiO 2 nanotubes, this increase in activity was correlated with the concentration of H 2SO 4 solution.
基金Supported by the National Natural Science Foundation of China (No. 10975020)Key Laboratory of BeamTechnology and Material Modification of Ministry of Education, Beijing Normal University
文摘Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays (TINT) were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources (MEVVA, BNU, China) implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows: Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy (at longer wavelength, such as visible light) to be absorbed, which accorded well with the experimental results.
基金supported by the 2013 research program of Hanseo University in Korea
文摘To improve the photocatalytic efficiency of TiO2nanotubular catalyst,N doped and Pd decorated titania nanotubes was successfully synthesized via anodizing,hydrazine hydrate treatment and photoreduction of Pd ions.The small Pd nanoparticles were precipitated on TiO2nanotubes through photoreduction of Pd ions,and its distribution is relatively homogeneous.From X-ray photoelectron spectrometry(XPS) result,the N 1s spectrum represents two peaks with binding energy at 399.7 and 400.7 eV,which suggests that the nitrogen elements doped by hydrazine hydrate treatment are located in interstitial sites of the TiO2crystalline structure.For N doped TiO2nanotubes with Pd particles,a high photocurrent was detected due to increase of interface charge carrier separation rate.Moreover,N doped and Pd decorated TiO2nanotubes exhibited much higher dye destruction efficiency and rate constant due to the synergistic effect of the N dopant and the Pd deposition on TiO2nanotubes.
基金the National Natural Science Foundation of China[grant numbers 81530051,31800790 and 31670966]Shaanxi Provincial Key Research and Development Plan Project(2019SF-031)+2 种基金Young Talent fund of University Association for Science and Technology in Shaanxi,China(20190304)supported by Danmarks Frie Forskningsfond(9040-00219B)Carlsbergfondet。
文摘Mesoporous silica thin film has been widely used in various fields,particularly the medical implant coating for drug delivery.However,some drawbacks remain with the films produced by traditional method(evaporation-induced self-assembly,EISA),such as the poor permeability caused by their horizontal aligned mesochannels.In this study,the vertical aligned mesoporous silica thin film(VMSTF)is uniformly grown alongside the walls of titania nanotubes array via a biphase stratification growth method,resulting in a hierarchical two-layered nanotubular structure.Due to the exposure of opened mesopores,VMSTF exhibits more appealing performances,including rapid degradation,efficient small-molecular drug(dexamethasone)loading and release,enhanced early adhesion and osteogenic differentiation of MC3T3-E1 cells.This is the first time successfully depositing VMSTF on nanoporous substrate and our findings suggest that the VMSTF may be a promising candidate for bone implant surface coating to obtain bioactive performances.