In this study biomimetic fluoridated phosphate doped hydrophilic coatings with various ions on CoCrMo alloy were pre- pared by electrodeposition. Cu and Zn ions were chosen for doping because of their well known antib...In this study biomimetic fluoridated phosphate doped hydrophilic coatings with various ions on CoCrMo alloy were pre- pared by electrodeposition. Cu and Zn ions were chosen for doping because of their well known antibacterial activity. The struc^xes of the coatings were identified using Fourier-transform Infrared （FTIR） analysis. X-ray Diffraction （XRD） analysis was performed to evaluate crystallite dimensions of the specimen surface. The contact angle was measured in order to establish the hydrophilic/hydrophobic balance and to compute surface energy. All studied samples have a hydrophilic character which is weaken after doping. The time evolution of ions releasing from the coatings was evaluated with an inductively plasma mass spectrometer after immersion in saline phosphate. The hemolytic experiments indicate that except the fluoridated coatings doped with Zn which is slightly hemolytic, all other samples are non hemolytic. The test for antibacterial activity for Staphy- lococcus aureus and Pseudomonas aeruginosa indicated that the fluoridated biomimetic coating doped with various positive ions increases bacterial growth inhibition level significantly. Fluoridated phosphate coating doped with Cu has best antibacterial activity展开更多
The aim of the present paper is to characterize bioinspired chitosan （CS） ＋ hydroxyapatite （HA） coatings with various components ratio on a zirconium alloy with titanium. The coatings were characterized by FT-IR,...The aim of the present paper is to characterize bioinspired chitosan （CS） ＋ hydroxyapatite （HA） coatings with various components ratio on a zirconium alloy with titanium. The coatings were characterized by FT-IR, SEM, hydrophilic/hydrophobic balance, adherence, roughness, electrochemical stability and in vitro cell response. Electrochemical tests, including potentio- dynamic polarization curves and electrochemical impedance spectroscopy, were performed in normal saline physiological solution. Cell viability of MC3T3-E1 osteoblasts, lactate dehydrogenase, nitric oxide, and Reactive Oxygen Species （ROS） levels, as well as actin cytoskeleton morphology, were evaluated as biological in vitro tests. The results on in vitro cell response indicated good cell membrane integrity and viability for all samples, but an increased cell number, a decreased ROS level and a better cytoskeleton organization were noticed for the sample with a higher CS content. The coating with highest CS concen- tration indicated the best performance based on the experimental data. The highest hydrophilic character, highest resistance to corrosion and best biocompatibility as well recommend this coating for bioapplications in tissue engineering.展开更多
Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer（SAN）blends with low content of ion-exchanger particles（5 wt.%）. The membranes obtained by phase inversion were used for the removal of...Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer（SAN）blends with low content of ion-exchanger particles（5 wt.%）. The membranes obtained by phase inversion were used for the removal of copper ions from synthetic wastewater solutions by electrodialytic separation. The electrodialysis was conducted in a three cell unit, without electrolyte recirculation. The process, under potentiostatic or galvanostatic control, was followed by p H and conductivity measurements in the solution. The electrodialytic performance,evaluated in terms of extraction removal degree（rd） of copper ions, was better under potentiostatic control then by the galvanostatic one and the highest（over 70%） was attained at8 V. The membrane efficiency at small ion-exchanger load was explained by the migration of resin particles toward the pores surface during the phase inversion. The prepared membranes were characterized by various techniques i.e. optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis and contact angle measurements.展开更多
文摘In this study biomimetic fluoridated phosphate doped hydrophilic coatings with various ions on CoCrMo alloy were pre- pared by electrodeposition. Cu and Zn ions were chosen for doping because of their well known antibacterial activity. The struc^xes of the coatings were identified using Fourier-transform Infrared （FTIR） analysis. X-ray Diffraction （XRD） analysis was performed to evaluate crystallite dimensions of the specimen surface. The contact angle was measured in order to establish the hydrophilic/hydrophobic balance and to compute surface energy. All studied samples have a hydrophilic character which is weaken after doping. The time evolution of ions releasing from the coatings was evaluated with an inductively plasma mass spectrometer after immersion in saline phosphate. The hemolytic experiments indicate that except the fluoridated coatings doped with Zn which is slightly hemolytic, all other samples are non hemolytic. The test for antibacterial activity for Staphy- lococcus aureus and Pseudomonas aeruginosa indicated that the fluoridated biomimetic coating doped with various positive ions increases bacterial growth inhibition level significantly. Fluoridated phosphate coating doped with Cu has best antibacterial activity
文摘The aim of the present paper is to characterize bioinspired chitosan （CS） ＋ hydroxyapatite （HA） coatings with various components ratio on a zirconium alloy with titanium. The coatings were characterized by FT-IR, SEM, hydrophilic/hydrophobic balance, adherence, roughness, electrochemical stability and in vitro cell response. Electrochemical tests, including potentio- dynamic polarization curves and electrochemical impedance spectroscopy, were performed in normal saline physiological solution. Cell viability of MC3T3-E1 osteoblasts, lactate dehydrogenase, nitric oxide, and Reactive Oxygen Species （ROS） levels, as well as actin cytoskeleton morphology, were evaluated as biological in vitro tests. The results on in vitro cell response indicated good cell membrane integrity and viability for all samples, but an increased cell number, a decreased ROS level and a better cytoskeleton organization were noticed for the sample with a higher CS content. The coating with highest CS concen- tration indicated the best performance based on the experimental data. The highest hydrophilic character, highest resistance to corrosion and best biocompatibility as well recommend this coating for bioapplications in tissue engineering.
文摘Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer（SAN）blends with low content of ion-exchanger particles（5 wt.%）. The membranes obtained by phase inversion were used for the removal of copper ions from synthetic wastewater solutions by electrodialytic separation. The electrodialysis was conducted in a three cell unit, without electrolyte recirculation. The process, under potentiostatic or galvanostatic control, was followed by p H and conductivity measurements in the solution. The electrodialytic performance,evaluated in terms of extraction removal degree（rd） of copper ions, was better under potentiostatic control then by the galvanostatic one and the highest（over 70%） was attained at8 V. The membrane efficiency at small ion-exchanger load was explained by the migration of resin particles toward the pores surface during the phase inversion. The prepared membranes were characterized by various techniques i.e. optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis and contact angle measurements.
