Iron oxide nanocomposite, mri t2 contrast agent comprising the same and process for preparing the sames

PURPOSE: An iron oxide nanocomposite and a magnetic resonance image (MRI) T_2 contrast agent containing the same are provided to remarkably enhance T_2 contrast effect in the use of same concentration of iron oxide nanoparticles because r_2 relaxation is twice greater than r_2 relaxation of a conventional MRI T_2 contrast agent. CONSTITUTION: An iron oxide nanocomposite has surfactant-covered ferrimagnetic iron oxide nanoparticles capped with polyethylene glycol-phospholipid. An MRI T_2 contrast agent contains the iron oxide nanocomposites. A method for preparing the iron oxide nanocomposites comprises the steps of: heating a mixture of an iron precursor, a surfactant, and an organic solvent and preparing surfactant-covered ferrimagnetic iron oxide nanoparticles; and capping the surfactant-covered ferrimagnetic iron oxide nanoparticles with polyethylene glycol-phospholipid.