Non-specific cellular uptake of surface-functionalized quantum dots.
We report a systematic empirical study of nanoparticle internalization into cells via non-specific pathways. The nanoparticles were comprised of commercial quantum dots (QDs) that were highly visible under a fluorescence confocal microscope. Surface-modified QDs with basic biologically significant moieties, e.g. carboxyl, amino, and streptavidin, were used, in combination with surface derivatization with polyethylene glycol (PEG) for a range of immortalized cell lines. Internalization rates were derived from image analysis and a detailed discussion about the effect of nanoparticle size, charge and surface groups is presented. We find that PEG derivatization dramatically suppresses the non-specific uptake while PEG-free carboxyl and amine functional groups promote QD internalization. These uptake variations displayed a remarkable consistency across different cell types. The reported results are important for experiments concerned with cellular uptake of surface-functionalized nanomaterials, both when non-specific internalization is undesirable and when it is intended for material to be internalized as efficiently as possible.
Kelf
T A
TA
MQ Photonics Centre, Faculty of Science, Macquarie University, Sydney, Australia.
Sreenivasan
V K A
VK
Sun
J
J
Kim
E J
EJ
Goldys
E M
EM
Zvyagin
A V
AV
D000818:Animals; D045744:Cell Line, Tumor; D004705:Endocytosis; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D010316:Particle Size; D045663:Quantum Dots; D051381:Rats; D013499:Surface Properties