Comparative biodistribution of thin‐coated iron oxide nanoparticles TCION: Effect of different bisphosphonate coatings

Abstract

Abstract Because the nature of their coatings influences the biodistribution of nanocolloids, five different bisphosphonates bearing OH, NH 2 , NMe 2 , and N+Me 3 groups were evaluated in vivo. 59 Fe‐labeled iron cores were coated by the different molecules and tested by intravenous injection to healthy adult male Wistar rats. The initial phase was estimated with 59 Fe‐ and 99m Tc‐labeled nanoparticles biodistribution. The different coatings do not change hydrodynamic radius (∼12 nm) and relaxivities. The negative surface charge is half for particles coated with bisphosphonates bearing quaternary ammonium compared to those bearing a hydroxyl function. Nanoparticle vascular initial half disappearance time range between 25 and 39 min, with hepatic capture between 50 and 80% ID at 18 h. Bones and muscles fix globally around 35 % ID at 18 h, with high concentrations in the mineral bones. Hydroxy‐bisphosphonates and quaternary ammonium‐bisphosphonate‐coated nanoparticles are the most efficient for blood remanence, weak liver capture, and bone targeting. Drug Dev. Res. 54:173–181, 2001. © 2002 Wiley‐Liss, Inc.