Quantification of intercellular heterogeneity in nanoparticle association is of paramount interest in research investigating applications of nanoparticles in the biomedical space. In this work, gold nanoparticle association (AuNP) in cell populations was quantified using synchrotron X-ray fluorescence microscopy (XRF) for 3 different cell lines (PC-3, Caco2 and MDA-MB-231) and 2 nanoparticle co-culture times (30 min and 10% of each respective cell lines' doubling time). Heterogeneity in association between single cells in the same population was dependant on cell line as well as co-culture time. AuNP association heterogeneity increased with co-culture time for 2 out of the 3 cell lines. Regardless of mean association quantity and measured intercellular heterogeneity, all data were best described by log normal distributions. Mean association between cell lines was statistically different at 30 min, yet indistinguishable at 10% doubling time. Heterogeneity between cell lines which demonstrated statistical differences in distribution can exist despite having statistically indistinguishable means.
Keywords: Cell population; Distribution; Nanoparticles; Rare cells; Statistics; Uptake.