Open AccessQuantification of Nanoparticle Dose and Vesicular Inheritance in Proliferating Cells
Author(s) -
Huw D. Summers,
M. Rowan Brown,
Mark D. Holton,
James A. Tonkin,
Nicole Hondow,
Andrew P. Brown,
Rik Brydson,
Paul Rees
Publication year - 2013
Publication title -
acs nano
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.554
H-Index - 382
eISSN - 1936-086X
pISSN - 1936-0851
DOI - 10.1021/nn4019619
Subject(s) - nanoparticle , flow cytometry , biophysics , endocytosis , vesicle , materials science , quantum dot , nanotechnology , biological system , cell , chemistry , biology , microbiology and biotechnology , membrane , biochemistry
Assessing dose in nanoparticle-cell interactions is inherently difficult due to a complex multiplicity of possible mechanisms and metrics controlling particle uptake. The fundamental unit of nanoparticle dose is the number of particles internalized per cell; we show that this can be obtained for large cell populations that internalize fluorescent nanoparticles by endocytosis, through calibration of cytometry measurements to transmission electron microscopy data. Low-throughput, high-resolution electron imaging of quantum dots in U-2 OS cells is quantified and correlated with high-throughput, low-resolution optical imaging of the nanoparticle-loaded cells. From the correlated data, we obtain probability distribution functions of vesicles per cell and nanoparticles per vesicle. Sampling of these distributions and comparison to fluorescence intensity histograms from flow cytometry provide the calibration factor required to transform the cytometry metric to total particle dose per cell, the mean value of which is 2.4 million. Use of the probability distribution functions to analyze particle partitioning during cell division indicates that, while vesicle inheritance is near symmetric, highly variable vesicle loading leads to a highly asymmetric particle dose within the daughter cells.