Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice.
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.
Schipper
Meike L
ML
Molecular Imaging Program at Stanford (MIPS), Department of Radiology, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427, USA.
Iyer
Gopal
G
Koh
Ai Leen
AL
Cheng
Zhen
Z
Ebenstein
Yuval
Y
Aharoni
Assaf
A
Keren
Shay
S
Bentolila
Laurent A
LA
Li
Jianquing
J
Rao
Jianghong
J
Chen
Xiaoyuan
X
Banin
Uri
U
Wu
Anna M
AM
Sinclair
Robert
R
Weiss
Shimon
S
Gambhir
Sanjiv S
SS
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
D010455:Peptides; D011092:Polyethylene Glycols