Non-specific cellular uptake of surface-functionalized quantum dots

TL;DR

This study systematically investigates how surface modifications of quantum dots influence their non-specific internalization into various cell lines, revealing that PEG reduces uptake while certain functional groups promote it.

Contribution

It provides detailed empirical data on how nanoparticle surface chemistry affects cellular internalization across multiple cell types, highlighting the role of PEG and functional groups.

Findings

PEG-derivatization suppresses nanoparticle uptake

Carboxyl and amine groups promote internalization

Uptake behavior is consistent across cell types

Abstract

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, streptavidin were used, in combination with the surface derivatization with polyethylene glycol (PEG) in 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 also when it is intended for material to be internalized as efficiently as possible. Published article at: http://iopscience.iop.org/0957-4484/21/28/285105/