NC100150 injection, a preparation of optimized iron oxide nanoparticles for positive-contrast MR angiography

A preparation of monocrystalline iron oxide nanoparticles with an oxidized starch coating, currently in clinical trials (NC100150 Injection; CLARISCAN (TM)), was characterized by magnetization measurements, relaxometry, and ph oton correlation spectroscopy. By combining the results with a measure of i ron content, one can obtain the size and magnetic attributes of the iron co res, including the relevant correlation times for outer sphere relaxation ( tau(SO) and tau(D)) and Information about the interaction of the organic co ating with both core and solvent, The results are 6.43 nm for the iron oxid e core diameter, a magnetic moment of 4.38 x 10(-17) erg/G, and a water-pen etrable coating region of oxidized oligomeric starch fragments and entraine d water molecules, The latter extends the hydrodynamic diameter to 11.9 nm and lowers the average diffusivity of solvent about 64% (which increases ta u(D) accordingly). The nanoparticles show little size-polydispersity, evide nced by the lowest value of r(2)/r(1) at 20 MHz reported to date, an asset for magnetic resonance angiography, (C) 2000 Wiley-Liss, Inc.