Size and Cell Type Dependent Uptake of Silica NanoparticlesI-Lun Hsiao1,3, Annika Mareike Gramatke1, Rastko Joksimovic2, Marek Sokolowski2, Michael Gradzielski2 and Andrea Haase1*
- *Corresponding Author:
- Andrea Haase
D - 10589 Berlin, Germany
E-mail: [email protected]
Received Date: November 05, 2014; Accepted November 24, 2014; Published Date: December 03, 2014
Citation: Hsiao I, Gramatke AM, Joksimovic R, Sokolowski M, Gradzielski M, et al. (2014) Size and Cell Type Dependent Uptake of Silica Nanoparticles. J Nanomed Nanotechnol 5:248. doi:10.4172/2157-7439.1000248
Copyright: © 2014 Hsiao I, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
As silica nanoparticles (SiO2 NP) gain increasing interest for medical applications it is important to understand their potential adverse effects for humans. Here we prepared well-defined core-shell fluorescently labelled SiO2 NP of 15, 60 and 200 nm diameter and analyzed their cytotoxicity in THP-1 derived macrophages, A549 epithelial cells, HaCaT keratinocytes and NRK-52E kidney cells. We observed a size-dependent cytotoxicity in all cell types in serumfree conditions. HaCaT cells were least and macrophages or lung derived A549 cells were highly sensitive towards SiO2 NP treatment. Differences in cytotoxicity could be correlated with different uptake rates. By using flow cytometry and confocal microscopy we quantified the uptake. Furthermore we used specific inhibitors for clathrin- and caveolinmediated endocytosis to elucidate the uptake mechanisms, which were found to be dependent on the NP size and the cell type. Clathrin-mediated endocytosis was involved in the uptake of SiO2 NP of all sizes and was the major pathway for 60 nm or 200 nm SiO2 NP. Caveolin-mediated endocytosis contributed to the uptake of 60 and 200 nm SiO2 NP in THP-1 macrophages but only to uptake of 200 nm SiO2 NP in A549. However, in the presence of serum all SiO2 NP were non-toxic. The presence of serum furthermore could alter the uptake mechanism. In summary, this study demonstrates size- and cell type dependent differences in SiO2 NP uptake and toxicity.