Fe~(3+) ions anchored to Fe@O-MWCNTs as double impact T_2 MRI contrast agents

摘要

Fe~(3+) ions were anchored via complexation onto the oxidized multiwall carbon nanotubes containing encapsulated iron-based nanoparticles (Fe@O-MWCNTs) yielding hybrids Fe(Ⅲ)/Fe@O-MWCNTs for application as MRI contrast agents. After washing, no free Fe~(3+) ions were observed in the solution. A 120 mg Fe~(3+) was coordinated by each 1 gram of Fe@O-MWCNTs with a formation of stable hybrids. Relaxation times T1 and T2 of water protons were measured for the suspensions of hybrids. At 7.1 T relaxivity, r2 of Fe@O-MWCNT and Fe(Ⅲ)/Fe@O-MWCNT was 25 and 35 s~(-1) ml mg~(-1), respectively, whereas at 0.4 T r2-values were equal. Additionally, T1/T2 ratio was found in a range of 17-104, which is a promising value in the light of application of the proposed materials as potential T2 MRI contrast agents.