Synthesis and in vitro and in vivo evaluation of manganese(III) porphyrin-dextran as a novel MRI contrast agent.

5-(4-Aminophenyl)-10,15,20-tris(4-sulfonatophenyl) manganese(III) porphyrin conjugated with dextran was synthesized. Its potential of being used as a tumor-targeting magnetic resonance imaging contrast agent was evaluated in vitro and in vivo. The results demonstrated that the compound has a longitudinal relaxivity (R(1)) higher than Gd-DTPA, low cytotoxicity and binding specificity to tumor cell membrane.