Abstract
Magnetic nanoparticles are used to enhance the image contrast of magnetic resonance imaging (MRI). However, the development of magnetic nanoparticles with a low dose/high image contrast and non-toxicity is currently a major challenge. In this study, cobalt-substituted hydroxyapatite nanoparticles deposited on titanium (Ti-CoHA) and cobalt-substituted hydroxyapatite nanoparticles deposited on titanium dioxide nanotubes (TNT-CoHA) were synthesized by the electrochemical deposition method. The particle sizes of Ti-CoHA and TNT-CoHA were 418.6 nm and 127.5 nm, respectively, as observed using FE-SEM. It was shown that CoHA can be obtained with a smaller particle size using a titanium dioxide nanotube (TNT) electrode plate. However, the particle size of TNT-CoHA is smaller than that of Ti-CoHA. The crystal size of the internal cobalt oxide of CoHA was calculated by using an XRD pattern. The results indicate that the crystal size of cobalt oxide in TNT-CoHA is larger than that of the cobalt oxide in Ti-CoHA. The larger crystal size of the cobalt oxide in TNT-CoHA makes the saturation magnetization (Ms) of TNT-CoHA 12.6 times higher than that of Ti-CoHA. The contrast in MRIs is related to the magnetic properties of the particles. Therefore, TNT-CoHA has good image contrast at low concentrations in T2 images. The relaxivity coefficient of the CoHA was higher for TNT-CoHA (340.3 mM−1s−1) than Ti-CoHA (211.7 mM−1s−1), and both were higher than the commercial iron nanoparticles (103.0 mM−1s−1). We showed that the TNT substrate caused an increase in the size of the cobalt oxide crystal of TNT-CoHA, thus effectively improving the magnetic field strength and MRI image recognition. It was also shown that the relaxivity coefficient rose with the Ms. Evaluation of biocompatibility of CoHA using human osteosarcoma cells (MG63) indicated no toxic effects. On the other hand, CoHA had an excellent antibacterial effect, as shown by E. coli evaluation, and the effect of TNT-CoHA powder was higher than that of Ti-CoHA powder. In summary, TNT-CoHA deposited electrochemically on the TNT substrates can be considered as a potential candidate for the application as an MRI contrast agent. This paper is a comparative study of how different electrode plates affect the magnetic and MRI image contrast of cobalt-substituted hydroxyapatite (CoHA) nanomaterials.
Highlights
Magnetic Resonance Imaging (MRI) is a safe diagnostic method
This study investigated the effects of pure titanium and titanium dioxide nanotube substrates on the magnetic, magnetic resonance imaging, and biological behavior of cobalt-substituted hydroxyapatite
The particles collected from the Ti and titanium dioxide nanotube (TNT) plates were the samples used in the experiments (Ti-cobalt-substituted hydroxyapatite (CoHA) and TNT-CoHA)
Summary
Magnetic Resonance Imaging (MRI) is a safe diagnostic method. The use of a targeting material [1] or contrast agent enhances the contrast between normal tissue and pathological tissue [2,3]. When the water molecules diffuse to the rim of the induced dipole moment, the magnetic relaxation process of the water proton interferes, and the spin–spin relaxation time (T2) is shortened so that the semaphore intensity of the water molecules in T2-weighted (T2WI) imaging is reduced [5] This phenomenon causes magnetic nanoparticles to be negatively contrasted in T2WI magnetic resonance imaging, reducing the strength of tissue semaphores in the image and increasing the contrast of the surrounding image [6]. Previous literature has reported on ways to increase the strength of magnetic fields, for example, cobalt iron ferrite combined with carbon nanotubes used for an annealing treatment effectively enhanced the contrast of MRI images [11].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
