Synthesis and characterization of cobalt ferrites as MRI contrast agent

The objective of this study was to synthesize, characterization and in vivo MRI experiment of cobalt ferrites as contrast agent. Iron oxide nanoparticles and cobalt ferrites were prepared by co-precipitation method. Iron oxides nanoparticles and cobalt ferrites were characterized by XRD, SEM, EDX, VSM and MRI. XRD analysis confirmed the spinel cubic structure of Fe3O4 with Miller indices (2 0 0), (2 2 0), (3 1 1), (4 0 0), (4 4 0) and average size of magnetic nanoparticles and cobalt ferrites were calculated about 11.13 nm, 12.21 nm and 16.85 nm using Scherer formula. XRD pattern confirmed that doping of Co increased the grain size of the magnetic nanoparticles. The morphology of iron oxide nanoparticles and cobalt ferrites were investigated by scanning electron microscope (SEM) and negligible agglomeration was found in ferrites. Spectra of EDX depicted the Fe, O and Cl elements in IONP. Magnetic properties were studied between Ms versus H using vibrating sampling magnetometer (VSM). Saturation magnetization (Ms) was enhanced with the doping concentration (20 %wt, 40 %wt) of Co with Fe3O4. MRI experiments were performed at low field MRI unit (0.35 Tesla, MAGNETOM) at open MRI diagnostic center Rawalpindi. T1-W, T2-W MRI images of liver and stomach of rabbits were taken using spin echo (SE) at TE = 15 ms and TR = 400 ms. IQ View software was used to estimate the intensity of signal induced by contrast agent pure iron oxides and cobalt ferrites (for liver, I = 1433 +/- S.D = 111.5, spleen, I = 1009 +/- S.D = 96.5), Co doped iron oxides nanoparticles (for liver, I = 1513 +/- S.D = 102.2, spleen I = 1694 +/- S.D = 219.2). This study concluded that cobalt ferrites induced high signal intensity of T2 contrast agents on liver and spleen as compared to iron oxides nanoparticles to diagnose many diseases in liver and spleen for clinical use of MR contrast agents. (C) 2020 The Authors. Published by Elsevier Ltd.