BACKGROUND:In order to overcome the shortcomings of single materials, antibiotics-loaded hydroxyapatite/titanium composites have attracted people’s attentions.
OBJECTIVE:To evaluate the biocompatibility of vancomycin/hydroxyapatite/titanium nanotubes.
METHODS:Mouse osteoblasts, MC-3T3-E1, were co-cultured with titanium (Cp-T), TiO2nanotubes, and vancomycin/hydroxyapatite/titanium nanotubes, respectively. Cel morphology and growth were observed after 1, 3 and 5 days of co-culture under inverted microscope and scanning electron microscope. The cel proliferation was detected by AO-EB method. The total protein, calcium and alkaline phosphatase levels were detected at 7 and 14 days of co-culture.
RESULTSAND CONCLUSION:The MC-3T3-E1 cels with good viability and morphology adhered wel on the surface of vancomycin/hydroxyapatite/titanium nanotubes compared with those on the surface of pure titanium and TiO2nanotubes under the scanning electron miscroscope. Moreover, there were a large amount of pseudopodia on the surface of composite nanotubes. Compared with the other two groups, the cel number on the surface and the levels of intracelular calcium and alkaline phosphatase were al higher in the vancomycin/hydroxyapatite/titanium nanotubes group. These findings suggest that the vancomycin/hydroxyapatite/titanium nanotubes have good biocompatibility and no cytotoxicity.

BACKGROUND: Present studies have proved that titanium coating nanotubes cannot only promote the biological activity of the material itself, but also be used as a drug carrier loading antibiotics and growth factors. OBJECTIVE: To investigate the antibacterial properties of vancomycin/hydroxyapatite/titanium dioxide nanotubes in vitro and in vivo. METHODS: The releasing property in vitro of vancomycin/hydroxyapatite/titanium dioxide nanotubes and vancomycin/titanium dioxide nanotubes were detected. And 1010/L Staphylococcus aureus dilution was put onto the commercial titanium, titanium dioxide nanotube and vancomycin/hydroxyapatite/titanium dioxide nanotube, respectively. Twenty-four hours later, the bacterial growth and activity was observed by scanning electron microscope and confocus scanning electron microscope, respectively. RESULTS AND CONCLUSION: Scanning electron microscope showed: the number of Staphylococcus aureus was the least on the vancomycin/hydroxyapatite/titanium dioxide nanotube, and the bacterial morphology was destroyed. Confocus scanning electron microscope observed: the number of bacteria and viable bacteria was the least on the vancomycin/hydroxyapatite/titanium dioxide nanotube, and the most on the commercial titanium. Besides, the releasing time of vancomycin from the hydroxyapatite/titaniumdioxide nanotube was up to 18 days, but the releasing time of vancomycin was only 4 hours from the titanium dioxide nanotube. In conclusion, the vancomycin/hydroxyapatite/titanium dioxide nanotube has good antibacterial property and slow-releasing performance.

BACKGROUND:Hydroxyapatite has excellent biocompatibility, but biocompatibility of nano-hydroxyapatite/TiO2 nanotube composites is rarely reported.
OBJECTIVE:To evaluate the biocompatibility of nano-hydroxyapatite/TiO2 nanotube composites.
METHODS:First, the TiO2 nanotubes were fabricated on the surface of the titanium by anodic oxidation
technique. Second, the nano-hydroxyapatite/TiO2 nanotube composites were fabricated by electrodeposition technique. The surface morphology of the composites was observed by scanning electron microscopy. Mouse osteoblasts MC-3T3-E1 were co-cultured with the nano-hydroxyapatite/TiO2 nanotube composites, TiO2 nanotubes and titanium, and commercial y pure titanium to observe the celladhesion, proliferation and necrosis on scaffolds.
RESULTS AND CONCLUSION:The morphology of the TiO2 nanotubes and nano-hydroxyapatite/TiO2 nanotube composites could be control ed by altering the conditions of the anodic oxidation and electrodeposition. Under the inverted microscope, after 3 days of co-culture with TiO2 nanotubes and nano-hydroxyapatite/TiO2 nanotube composites, MC-3T3-E1 cells proliferated wel with regular shape and arrangement that were superior to those on commercial y pure titanium. Under scanning electron microscope, the cellwere adhered and proliferated wel on the surface of the TiO2 nanotubes and nano-hydroxyapatite/TiO2 nanotube composites after 3 days. Apoptosis rate of the cells was significantly reduced on the surface of nano-hydroxyapatite/TiO2 nanotube composites (7.8%) compared with TiO2 nanotubes (9.4%) and commercial y pure titanium (13.5%), indicating nano-hydroxyapatite/TiO2 nanotube composites have good biocompatibility.

The research of sleep staging is an important basis of evaluating sleep quality and diagnosing diseases. In order to achieve automatic sleep staging, we proposed a new method which combines with principal component analysis (PCA) and support vector machine (SVM) for automatic sleep staging. Firstly, we used PCA to reduce dimension of time-frequency-space domains and nonlinear dynamical characteristics of sleep EEG from 5 subjects to reduce data redundancy. Secondly, we used 1-a-1 SVM to classify sleep stages. The results showed that the correct rate can reach 89.9%, which was better than those of many other similar studies.
Electroencephalography ; Humans ; Nonlinear Dynamics ; Principal Component Analysis ; Sleep Stages ; Support Vector Machine

BACKGROUND:TiO2 nanotube array prepared by anodic oxidation is a nanomaterial having a perfect promising application at present.
OBJECTIVE:To review the research progress of TiO2 nanotube in clinic.
METHODS:The key words were TiO2 nanotubes, anodization, and biomaterials. We retrieved PubMed Database for articles concerning the clinical application of TiO2 nanotube published from January 2000 to June 2013. Repetitive and old studies were excluded, and 47 literatures were included for the review.
RESULTS AND CONCLUSION:The summarized results of the 47 literatures showed that TiO2 nanotube promoted the adhesion and proliferation of osteoblasts and mesenchymal stem cells including human. In vivo experiments verified that TiO2 nanotube could be used as a carrier to carry other drugs such as growth factor and antibiotics so as to promote the biocompatibility of the materials and to prevent bacterial adhesion. Results suggested that TiO2 nanotube contributed to the osseointegration of the material in vivo, and had a good biocompatibility.