title: In vivo biodistribution and clearance studies using multimodal organically modified silica nanoparticles.
abstract: Successful translation of the use of nanoparticles from laboratories to clinics requires exhaustive and elaborate studies involving the biodistribution, clearance, and biocompatibility of nanoparticles for in vivo biomedical applications. We report here the use of multimodal organically modified silica (ORMOSIL) nanoparticles for in vivo bioimaging, biodistribution, clearance, and toxicity studies. We have synthesized ORMOSIL nanoparticles with diameters of 20-25 nm, conjugated with near-infrared (NIR) fluorophores and radiolabeled them with (124)I, for optical and PET imaging in vivo. The biodistribution of the nontargeted nanoparticles was studied in nontumored nude mice by optical fluorescence imaging, as well by measuring the radioactivity from harvested organs. Biodistribution studies showed a greater accumulation of nanoparticles in liver, spleen, and stomach than in kidney, heart, and lungs. The clearance studies carried out over a period of 15 days indicated hepatobiliary excretion of the nanoparticles. Selected tissues were analyzed for any potential toxicity by histological analysis, which confirmed the absence of any adverse effect or any other abnormalities in the tissues. The results demonstrate that these multimodal nanoparticles have potentially ideal attributes for use as biocompatible probes for in vivo imaging.
authors.affiliation: Institute for Lasers, Photonics and Biophotonics, The State University of New York at Buffalo, Buffalo, NY 14260, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.forename: Indrajit
authors.initials: I
authors.lastname: Roy
authors.forename: Tymish Y
authors.initials: TY
authors.lastname: Ohulchanskky
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Vathy
authors.forename: Earl J
authors.initials: EJ
authors.lastname: Bergey
authors.forename: Munawwar
authors.initials: M
authors.lastname: Sajjad
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
mesh_terms: D000818:Animals; D001659:Biliary Tract / Q000378:metabolism; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D005720:Gamma Rays; D007267:Injections; D007457:Iodine Radioisotopes / Q000737:chemistry; D008027:Light; D008099:Liver / Q000378:metabolism; D008657:Metabolic Clearance Rate; D051379:Mice; D008853:Microscopy; D057054:Molecular Imaging; D053758:Nanoparticles / Q000737:chemistry*; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000633:toxicity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D007457:Iodine Radioisotopes; D009942:Organometallic Compounds; D012822:Silicon Dioxide