Nonfunctionalized Nanocrystals Can Exploit a Cell's Active Transport Machinery Delivering Them to Specific Nuclear and Cytoplasmic Compartments

Abstract

We use high content cell analysis, live cell fluorescent imaging, and transmission electron microscopy approaches combined with inhibitors of cellular transport and nuclear import to conduct a systematic study of the mechanism of interaction of nonfunctionalized quantum dots (QDs) with live human blood monocyte-derived primary macrophages and cell lines of phagocytic, epithelial, and endothelial nature. Live human macrophages are shown to be able to rapidly uptake and accumulate QDs in distinct cellular compartment specifically to QDs size and charge. We show that the smallest QDs specifically target histones in cell nuclei and nucleoli by a multistep process involving endocytosis, active cytoplasmic transport, and entering the nucleus via nuclear pore complexes. Treatment of the cells with an anti-microtubule agent nocodazole precludes QDs cytoplasmic transport whereas a nuclear import inhibitor thapsigargin blocks QD import into the nucleus. These results demonstrate that the nonfunctionalized QDs exploit the cell's active transport machineries for delivery to specific intranuclear destinations.

Multifactorial determinants that govern nanoparticle uptake by human endothelial cells under flow

“…46 Our findings additionally confirm that the nuclear pore has a size-specific cutoff band of approximately 3.8 to 4.0 nm, even with paralyzed nuclear transport machinery. 30 We found that negatively charged SiO 2 -NPs did not infiltrate into the cytoplasm of both live cells (ie, untreated cells and those treated with Triton X) and fixed/permeabilized cells under static conditions. However, under the influence of SS, the SiO 2 -NPs were bound to the cell membrane in live cells and confined to the cytoplasm in fixed/permeabilized cells.…”

“…This is in agreement with the work of Nabiev and colleagues, who demonstrated that the surface protonation of CdTe-QDs in the endolysosomal compartment -followed by their reversible and pHdependent aggregation -was responsible for their escape into the cytoplasm. 30 This phenomenon could also be attributed to the possible interactions of CdTe-QDs with the cytoplasmic proteins, thereby forming a "protein corona" that gave them different biological properties and subsequently determined the fate of CdTe-QD localization.…”

“…29 A systematic study of the mechanisms of interaction of nonfunctionalized CdTe and CdSe/ZnS QDs with a panel of live human cells of different origin has demonstrated that the nonfunctionalized QDs exploit the cell's active transport machineries for intranuclear delivery. 30 The effects of NPs such as carbon black, 31 silver, 32 metal oxides, 33 MgO, 34 SiO 2 , 35 QDs, 21 and polymeric NPs 19 on ECs have been studied under static conditions. However, no comprehensive study has been undertaken to evaluate the interaction of engineered NPs on human ECs under varying flow conditions.…”

Imaging of human colon cancer cells using He‐Ion scanning microscopy

“…Light microscopy and spectrometry (e.g. confocal microscopy and Raman spectroscopy) have proved indispensible for characterizing biological samples (Templeton et al, 2006;Nabiev et al, 2007;Jennifer et al, 2008). Light microscopy is compatible with in vivo characterization and provides three-dimensional (3D) information, although this technique is limited to a resolution of ∼100 nm (Guy & Colin, 2004).…”

CdTe quantum dots induce activation of human platelets: implications for nanoparticle hemocompatibility

“…5 Studies have shown that both negatively and positively charged QDs can be endocytosed, 6 and there is evidence that QDs exploit the cell's active-transport machineries for cytoplasmic and intranuclear delivery. 7 The major routes of human exposure to NP are transcutaneous, oral (enteric), or parenteral. Systemic delivery of NP-based therapeutic or diagnostic agents implies the interactions of NP with constituents of blood.…”