Patent ID: 8906346

Claim:
A contrast agent for contrast enhanced lymphography, comprising: iron oxide nanoparticles dispersed in an aqueous medium; and polyethyleneimine-graft-(polyethyleneglycol;poly3,4 dihydroxyphenylalanine), wherein the iron oxide nanoparticles are embedded in a micelle of the polyethyleneimine-graft-(polyethyleneglycol;poly3,4-dihydroxyphenylalanine), wherein the poly3,4-dihydroxyphenylalanine (PDOPA) is selected from L-PDOPA synthesized from N-carboxyl anhydride of L-DOPA(L-3,4-dihydroxyl phenylalanine) and D-PDOPA synthesized from N-carboxyl anhydride of D-DOPA(D-3,4-dihydroxyl phenylalanine) and L,D-PDOPA synthesized from N-carboxyl anhydride of L,D-DOPA, wherein the poly3,4-dihydroxyphenylalanine is represented by Structure C, wherein d ranges from 2 to 100.