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@#Traditional titanium implants do not completely meet the clinical requirements because they are bioinert. The surface of titanium implants, modified by strontium ions, can enhance osseointegration and reduce peri-implantitis. In this paper, the biological properties of titanium implant surfaces modified by strontium ions were reviewed. Strontium ions can be coated on the implant surface by hydrothermal treatment, electrochemical deposition, phosphate chemical conversion, flame-spraying, supramolecular self-assembly, magnetron sputtering, laser deposition and alkali etching. Implant surfaces modified by strontium ions can not only promote osteogenesis and early osseointegration but also inhibit bacterial growth and reduce postoperative infections. Even better osseointegration and antibacterial effects can be achieved when strontium ions are incorporated with other elements, such as silver, zinc, gallium, and calcium. However, most of the studies on the use of strontium ion-modified titanium implants are animal experiments and in vitro experiments, and the observation time is short compared with the actual service life of the implants. Thus, the conclusions obtained may be different from the actual clinical application, and the long-term effects need to be studied. In addition, the osteogenic effects of various modification methods also need to be compared. Future research can focus on the following points: ① to find efficient modification methods that can be widely used in the clinic; ②to study how to control the concentration of strontium ions near the implant to exert their biological function and reduce their toxic side effects; and ③ to conduct long-term follow-up clinical trials to observe their osteogenic and antibacterial effects.
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In this study, hydroxyapatite (HAp) was coated on titanium using electrochemical deposition (ECD) method at body fluid temperature. The titanium specimens for ECD were prepared by chemically etching treatment using 5M NaOH solution. The electrolyte mixed with 5 mM Ca(NO³)² and 2 mM NH⁴H²PO⁴ which has pH 5 (E2) was adjusted to pH 3 (E1) and pH 6 (E3). The different electric pulses of −10, −15, −30 mA were applied to each specimen. The temperature of electrolytes was kept at 37℃. E1-10, E1-15, E1-30, E2-10, E2-15, E2-30, E3-10, E3-15, and E3-30 groups were prepared for this study. Scanning electron microscope (SEM) images showed that E1-10 and E1-15 groups were not coated and the powder-shaped compounds were formed on E3-15 and E3-30 groups. The cracks were observed on the surface of E1-30 and E2-30 groups. The evenly and stable coated layer was deposited on E2-10, E2-15 and E3-10 groups. The layer coated on titanium surface had an HAp crystalline structure. E1-30 and E2-30 groups had low crystallinity, even though they had thick layer. HAp layer on for E2-10 group was well deposited on the surface because it more aligned to c-axis compared with other groups.
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Líquidos Corporais , Cristalinas , Durapatita , Eletrólitos , Concentração de Íons de Hidrogênio , Métodos , TitânioRESUMO
The facile and efficient synthetic route for Ag dendritic nanostructures on Indium tin oxide ( ITO) via electrodeposition was reported. The results showed that the Raman intensities of rhodamine 6G ( R6G) decreased with decreasing the loading concentration, and even at a low concentration of 10-10 mol/L, the signatures of R6G in Raman spectrum were still clearly observed. It indicated that the Ag dendritic nanostructures exhibited high surface-enhanced Raman scattering ( SERS) sensitivity. Moreover, the relative standard deviation ( RSD ) of band at 610 cm-1 was calculated to be 12 . 1%, 12 . 0%, 11 . 7%, 10 . 9%, 13. 2% and 14. 3%, respectively, corresponding with the concentration of R6G from 10-5 mol/L to 10-10 mol/L, which revealed that the Ag dendritic nanostructures could provide abundant hot spots and exhibited excellent reproducibility. In addition, the SERS spectrum of 3-mercaptopropionic acid (3MPA) also could be detected when its concentration was 10-5 mol/L. This method offers an easy and low-cost way to prepare Ag dendritic substrates and makes SERS detection more practicable.
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10.3969/j.issn.2095-4344.2013.25.002
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Magnetic nanowires not only have nanometer properties, but also have magnetic property of giant magnetoresistance. Recently, nanowires were applied widely in high density hard disk slider, super magnetic storage element, micro-sensors, micro-engine, biomedical engineering, etc. This artical reviews the current preparation method of nanowires, the template synthesis, including several general templates such as track-etched porous polycarbonate membrane, porous anodic aluminum oxide membrane and carbon nanotubes, as well asgrowth patterns of nanowires in the templates. The applications of nanowires in several biosensors are introduced.The applications will greatly improve current ways of sensor detection, which will open up new areas of the field of biosensor study.