Zwitterionic surface coating of quantum dots reduces protein adsorption and cellular uptake

Abstract

We have studied the effect of the zwitterionic surface coating of quantum dots (QDs) on their interaction with a serum supplemented cell medium and their internalization by human cervical carcinoma (HeLa) cells. Zwitterionic QDs showed negligible adsorption of human serum albumin (HSA) selected as a model serum protein, in contrast to similar but negatively charged QDs. The incorporation of zwitterionic QDs by HeLa cells was found to be lower than for negatively charged QDs and for positively charged QDs, for which the uptake yield was largest. Our results suggest that the suppression of protein adsorption, here accomplished by zwitterionic QD surfaces, offers a strategy that allows for reducing the cellular uptake of nanoparticles.

Evaluation of quantum dot conjugated antibodies for immunofluorescent labelling of cellular targets

“…The binding affinity of Qdot-Abs can also be affected by the surface charge they possess. For instance, positively charged Qdots are taken up by cells more readily than negatively charged or zwitterionic Qdots, which suppress protein adsorption and thus the formation of a protein corona [38]. Qdots with a zwitterionic surface have a zeta potential of near zero, are resistant to non-specific binding onto cells, and have a high colloidal stability [39].…”

In vivo fate of free and encapsulated iron oxide nanoparticles after injection of labelled stem cells

“…The difference in Fe uptake is unlikely to be due to electrostatic interactions, 25,33 as both formulations were highly positively charged (Fig. SI.1 c & d).…”

“…11,[19][20][21][22][23][24] The uptake efficiency of SPIONs is strongly influenced by their functionalization. 21,25 Recently, positively-charged DEAE (diethylaminoethyl)-dextran coated SPIONs have been synthesized for enhanced cellular uptake and MRI contrast. 20,22 Upon cell uptake, the clustering and confinement of these particles in endosomal and lysosomal compartments affects their abilities to alter the relaxation rate and hence relaxivity of the surrounding water molecules.…”

Analyse quantitativer Partikelaufnahme von Zellen über verschiedene Messmethoden

“…die Menge internalisierter Partikel als mittlere Masse von Au, die pro Zelle gefunden wird ( m Au ), ausgedrückt werden (siehe Abbildung ). Eine typische Methode für anorganische Partikel ist ICP‐MS oder verwandte Techniken . Da bei ICP‐MS üblicherweise keine laterale Auflösung implementiert ist, wird lediglich innerhalb eines Zellpellets die Menge an Elementen, aus dem die Partikel bestehen, bestimmt.…”