ABSTRACT
BACKGROUND: In the scheme of titanium surface modification and coating modification, the drug sustained-release system constructed by surface nanotube modification and hydroxyapatite coating modification has broad clinical application prospects. OBJECTIVE: To construct composite drug loading coating of titanium dioxide nanotube/hydroxyapatite loaded with vancomycin hydrochloride, and analyze the drug release performance and cytotoxicity of the composite coating in vitro. METHODS: A two-step anodic oxidation method was used to construct titanium dioxide nanotubes on the titanium surface, and the prepared hydroxyapatite was loaded on the surface of the nanotubes by electrophoretic deposition, so as to obtain a nanotube/hydroxyapatite composite coating structure. Subsequently, the composite coating was used as a drug-loaded platform, and vancomycin hydrochloride was loaded by physical adsorption to finally obtain a composite drug-loaded coating. The in vitro drug release properties of hydroxyapatite/vancomycin hydrochloride, titanium dioxide nanotubes/vancomycin hydrochloride, titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating were measured. Human osteoblasts were cultured with titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating extracts of different concentrations. MTT assay was used to detect cytotoxicity. Human osteoblasts were inoculated on the surface of hydroxyapatite, titanium dioxide nanotubes, titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride, and the changes of cell morphology were observed. RESULTS AND CONCLUSION: (1) Compared with hydroxyapatite/vancomycin hydrochloride, titanium dioxide nanotube/vancomycin hydrochloride coating, titanium dioxide nanotube/hydroxyapatite/vancomycin hydrochloride coating had a longer drug sustained-release effect. The release time exceeded 150 hours. (2) The 10%, 50%, and 100% concentration of titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating extract had no obvious cytotoxicity. The relative activity of osteoblasts was more than 70%. (3) The osteoblasts on the three kinds of coating surface grow well; the cytoskeleton was intact; and the nucleus-cytoplasm ratio of the cells was normal, which was not significantly different from the morphology of the cells in pure culture. (4) The results show that the coating of titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride has good drug release properties in vitro without obvious cytotoxicity.
ABSTRACT
In this study, gold nanotubes were fabricated by electrophoretic deposition using a titania nanotube layer as a template, and then the surface characteristics, biocompatibility and antibacterial effect of gold nanotubes were evaluated. Gold nanotubes of 100 nm diameter were fabricated by depositing 4 nm and 15 nm gold nanoparticles on anodized 100 nm titania nanotubes by citrate reduction and electrophoretic deposition. As a result of the UV-Vis diffuse spectrophotometer, 4 nm and 15 nm gold nanotubes showed strong absorption at 702~774 nm and 753~760 nm, respectively. Also, the maximum absorption wavelength was shifted to the longer wavelength as the coating time of the gold nanoparticles increased. FE-SEM observation and EDX analysis resulted that 0.1~0.5 wt% gold nanoparticles uniformly were stacked on the top layer of titania nanotubes. As a result of MTT cell test, the relative absorbance value of all experimental groups after 24 hours and 48 hours of incubation exceeded 70% indicating excellent biocompatibility. The effect of the near infrared laser light on the adhesion and growth of gold nanotubes showed excellent antibacterial activity regardless of the coating time of gold nanoparticles. Therefore, it is confirmed that the gold nanotube coating technology based on the titania nanotube template is supposed to be highly applicable to a titanium implant surface treatment technology with the remote control thermal treatment of a near-infrared laser.
Subject(s)
Absorption , Citric Acid , Nanoparticles , Nanotubes , TitaniumABSTRACT
The clinical success of dental implants can be improved by achieving optimum implant properties,such as their biomechanical and surface characteristics.Nano-structured coatings can play an important role in improving the implant surface.The purpose of the present study was to determine the most appropriate conditions for electrophoretic deposition (EPD) of nano-zirconia coatings on Ti-6Al-7Nb substrates and to evaluate the structural and biomechanical characteristics of these deposited coatings on the dental implants.EPD was used with different applied voltages and time periods to obtain a uniform layer of nano-zirconia on Ti-6Al-7Nb samples.The coated samples were weighed and the thickness of the product layer was measured.Surface analysis was performed by using optical microscopical examination,scanning electron microscope and X-ray diffraction phase analysis.For in vivo examination,48 screw-designed implants (24 uncoated and 24 nano-zirconia coated) were implanted in both tibiae of 12 white New Zealand rabbits and evaluated biomechanically after 4-and 12-week healing intervals.Results revealed that the use of different conditions for EPD affected the final coating film properties.Increasing the applied voltage and coating time period increased the deposited nano-zirconia film thickness and weight.By selecting the appropriate coating conditions,and analyzing scanning electron microscopical examination and XRD patterns,this technique could produce a thin and continuous nano-zirconia layer with a uniform thickness of the Ti-6Al-7Nb samples.Mechanically,the nano-zirconia-coated implants showed a highly statistically significant difference in removal torque values,while histologically these coated implants enhanced and promoted osseointegration after 4 and 12 weeks of healing,compared with the uncoated ones.In conclusion,EPD is an effective technique for providing a high quality nano-zirconia coating film on dental implant surfaces.Moreover,the osseointegration of these coated dental implants is improved compared with that of uncoated ones.
ABSTRACT
The clinical success of dental implants can be improved by achieving optimum implant properties,such as their biomechanical and surface characteristics.Nano-structured coatings can play an important role in improving the implant surface.The purpose of the present study was to determine the most appropriate conditions for electrophoretic deposition (EPD) of nano-zirconia coatings on Ti-6Al-7Nb substrates and to evaluate the structural and biomechanical characteristics of these deposited coatings on the dental implants.EPD was used with different applied voltages and time periods to obtain a uniform layer of nano-zirconia on Ti-6Al-7Nb samples.The coated samples were weighed and the thickness of the product layer was measured.Surface analysis was performed by using optical microscopical examination,scanning electron microscope and X-ray diffraction phase analysis.For in vivo examination,48 screw-designed implants (24 uncoated and 24 nano-zirconia coated) were implanted in both tibiae of 12 white New Zealand rabbits and evaluated biomechanically after 4-and 12-week healing intervals.Results revealed that the use of different conditions for EPD affected the final coating film properties.Increasing the applied voltage and coating time period increased the deposited nano-zirconia film thickness and weight.By selecting the appropriate coating conditions,and analyzing scanning electron microscopical examination and XRD patterns,this technique could produce a thin and continuous nano-zirconia layer with a uniform thickness of the Ti-6Al-7Nb samples.Mechanically,the nano-zirconia-coated implants showed a highly statistically significant difference in removal torque values,while histologically these coated implants enhanced and promoted osseointegration after 4 and 12 weeks of healing,compared with the uncoated ones.In conclusion,EPD is an effective technique for providing a high quality nano-zirconia coating film on dental implant surfaces.Moreover,the osseointegration of these coated dental implants is improved compared with that of uncoated ones.