Targeted polymerized liposome contrast agents

A polymerized liposome image contrast agent composition according to claim i wherein said hydrophilic head group comprises a lanthanide-diethylenetriamine pentaacetic acid chelate.

A polymerized liposome image contrast agent composition consisting essentially of:

• liposome forming lipids, said liposome forming lipids having active hydrophilic head groups selected from the group consisting of diethylenetriamine pentaacetic acid, ethylenedinitrile tetraacetic acid, tetraazacyclododecane 1,4,7,10-tetraacetic acid, and cyclohexane-1,2,-diamino-N,N'-diacetate, a portion of said active hydrophilic head groups having functional surface groups chelated with an image contrast enhancement agent and additional said active hydrophilic head groups having attached targeting active agents;
• said liposome forming lipids having hydrophobic tail groups polymerized with a hydrophobic tail group of an adjacent said liposome forming lipid through a functional group selected from the group consisting of diacetylene, olefin, acetylene, nitrile, styrene, ester, thiol, amide, .alpha., .beta.unsaturated ketone, and .alpha., .beta.unsaturated aldehyde;
• said hydrophilic head groups and said hydrophobic tail groups linked to said liposome forming lipid by a variable length linker portion selected from the group consisting of variable length polyethylene glycol, polypropylene glycol and polyglycine.