title: Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice.
abstract: This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 6-9 and 2-3, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects.
authors.affiliation: Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427, USA.
authors.forename: Meike L
authors.initials: ML
authors.lastname: Schipper
authors.forename: Gopal
authors.initials: G
authors.lastname: Iyer
authors.forename: Ai Leen
authors.initials: AL
authors.lastname: Koh
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cheng
authors.forename: Yuval
authors.initials: Y
authors.lastname: Ebenstein
authors.forename: Assaf
authors.initials: A
authors.lastname: Aharoni
authors.forename: Shay
authors.initials: S
authors.lastname: Keren
authors.forename: Laurent A
authors.initials: LA
authors.lastname: Bentolila
authors.forename: Jianquing
authors.initials: J
authors.lastname: Li
authors.forename: Jianghong
authors.initials: J
authors.lastname: Rao
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
authors.forename: Uri
authors.initials: U
authors.lastname: Banin
authors.forename: Anna M
authors.initials: AM
authors.lastname: Wu
authors.forename: Robert
authors.initials: R
authors.lastname: Sinclair
authors.forename: Shimon
authors.initials: S
authors.lastname: Weiss
authors.forename: Sanjiv S
authors.initials: SS
authors.lastname: Gambhir
mesh_terms: D000818:Animals; D008099:Liver / Q000378:metabolism; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D010316:Particle Size; D010455:Peptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D049268:Positron-Emission Tomography; D045663:Quantum Dots; D013154:Spleen / Q000378:metabolism; D013499:Surface Properties
chemical_list: D010455:Peptides; D011092:Polyethylene Glycols