Preparation and long-term biodistribution studies of a PAMAM dendrimer G5-Gd-BnDOTA conjugate for lymphatic imaging.

Aims: To demonstrate the use of gadolinium (Gd)-labeled dendrimers as lymphatic imaging agents and establish the long-term biodistribution (90-day) of this type of agent in mice.

Materials & Methods: A G5-Gd-BnDOTA dendrimer was prepared and injected into mice and monkeys for MR lymphangiography, and long-term biodistribution of the conjugate was studied.

Results: Administration of G5-Gd-BnDOTA in mice demonstrated a rapid uptake in the deep lymphatic system while injection in monkeys showed enhanced internal iliac nodes, indicating its general utility for lymphatic tracking.