Improved biocompatibility of anodized titanium implants by MnO nanoparticles

The surface addition of biocompatible metal oxide nanoparticles can significantly affect the physical, chemical, and biological properties of anodized titanium implants. Manganese is an important element for bone growth and regeneration and is essential for the body's vital systems. In this study, the biological properties of anodized titanium implants decorated with MnO nanoparticles were studied. At first, the effect of anodic oxidation voltage (15 V, 20 V, and 25 V) on the microstructure of titanium oxide nanotubes (TNTs) was investigated. Microstructural studies showed that the diameters of TNTs are increased by raising the applied voltage. Prepared TNTs with the applied voltage of 25 V exhibited a more uniform structure with an average inner diameter of 102 ± 15 nm. In the next step, MnO nanoparticles were synthesized through the thermal decomposition method. The effects of different surfactants, such as oleic acid and oleylamine, and various solvents, including dibenzyl ether and octadecene, on the size and morphology of the synthesized nanoparticles were studied. The results indicated that the MnO nanoparticles synthesized by dibenzyl ether solvent and oleic acid surfactant showed the smallest size and uniform morphology. Finally, the synthesized TNTs were decorated by the optimized MnO nanoparticles using the hydrothermal technique. X-ray diffraction (XRD) analysis was used to phase characterization. Microstructural studies were carried out by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. MTT and cell morphology tests were carried out for the biocompatibility evaluation of the specimens. The results showed that the anodized titanium decorated with MnO nanoparticles indicated the highest cell viability compared to the anodized and untreated samples. Microstructural studies demonstrated that the cells attached to the surface and spreading of filopodia in the anodized titanium decorated with MnO nanoparticles are higher than the other samples.