Bashar Issa1, Ihab M. Obaidat1,
Shahnaz Qadri2, Basil al-Ramadi3, Yousef Haik2,4
1Physics, UAE University, Al-Ain, Abu
Dhabi, United Arab Emirates; 2Mechanical Eng., UAE University,
Al-Ain, Abu Dhabi, United Arab Emirates; 3Medicine, UAE
University, Al-Ain, Abu Dhabi, United Arab Emirates; 4Center of
Research Excellence in Nanobiosciences, Univ. of North Carolina-Greensboro,
United States
We
studied the of 1/T1 and 1/T2 behaviour and effect of PEG coating for a new
class of magnetic nanoparticles (MNPs) Mn0.5Zn0.5GdxFe(2-x)O4 with Gd
concentration x = 0.02. MNPs were dispersed in gel with a range of
concentrations (in mM of Fe per kg) from 0.0 to 0.3. At 1.5 T, T1 and T2 were
measured at temperatures 26 oC. The measured 1/T1 and 1/T2 show linear
dependence on concentrations. Variation of R1,2 with concentration is larger
for the uncoated than for the coated particles due to smaller distance
separating the protons from MNPs. These nanoparticles have already been used
as hyperthermia agents and we are investigating the extension of their use as
MRI contrast agents.