Vascular magnetic resonance imaging agent comprising nanoparticles

A method for obtaining an MR image of the vascular compartment of an animal or a human subject which comprises:

• (a) administering to such a subject, an effective amount of a magnetic resonance imaging contrast agent in a physiologically acceptable medium, said contrast agent;
• (i) comprising a population of biodegradable superparamagnetic metal oxide particles, wherein said particles (a) are capable of being metabolized or excreted by a subject within about 1 week after administration, as evidenced by a return of proton relaxation rates of an affected organ or tissue of the subject to pre-administration levels, and (b) are associated with a protein;
• and
• (ii) has a blood half-life in the rat of at least about 17 minutes at a dose of about 2 mg of metal per kg of rat;
• and
• (b) recording such MR image of the vascular compartment.

A method for obtaining an MR image of the vascular compartment of an animal or a human subject which comprises:

• (a) administering to such a subject, an effective amount of a magnetic resonance imaging contrast agent in a physiologically acceptable medium, said contrast agent
• (i) comprising a population of biodegradable superparamagnetic metal oxide particles, wherein said particles (a) are capable of being metabolized or excreted by a subject within about 1 week after administration, as evidenced by a return of proton relaxation rates of an affected organ or tissue of the subject to pre-administration levels, and (b) are associated with a polypeptide;
• and
• (ii) has a blood half-life in the rat of at least about 17 minutes at a dose of about 2 mg metal per kg of rat;
• and
• (b) recording such MR image of the vascular compartment.

A method for obtaining an MR image of the vascular compartment of an animal or a human subject which comprises:

• (a) administering to such a subject, an effective amount of a magnetic resonance imaging contrast agent in a physiologically acceptable medium, said contrast agent
• (i) comprising a population of biodegradable superparamagnetic metal oxide particles, wherein said particles (a) are capable of being metabolized or excreted by a subject within about 1 week after administration, as evidenced by a return of proton relaxation rates of an affected organ or tissue of the subject to pre-administration levels, and (b) are associated with a hydroxyethyl starch;
• and
• (ii) has a blood half-life in the rat of at least about 17 minutes at a dose of about 2 mg metal per kg of rat;
• and
• (b) recording such MR image of the vascular compartment.