Table of Contents
Journal of Nanoscience
Volume 2016, Article ID 4023852, 9 pages
Research Article

In Vitro Cytotoxicity of Nanoparticles: A Comparison between Particle Size and Cell Type

1Pharmacology and Toxicology Division, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India
2School of Studies in Pharmaceutical Sciences, Jiwaji University, Gwalior 474011, India
3Saveetha University, Chennai 600077, India

Received 14 March 2016; Revised 15 June 2016; Accepted 30 June 2016

Academic Editor: Nikolai Khlebtsov

Copyright © 2016 Devashri Sahu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The reduction in size of Zinc oxide (ZnO) and Silicon dioxide (SiO2) particles from micron to nano scale offers unique physical characteristics on one hand while making them cytotoxic on other hand. The present study was aimed at comparing cytotoxic effects of ZnO and SiO2 nanoparticles with their micron size and secondary aim was to compare responses of these particles to two different cell types, namely, human lung epithelial cells (L-132) and human monocytes (THP-1). The L-132 and THP-1 cells were exposed to nano and micron size of ZnO and SiO2 particles with different concentrations (5–500 μg/mL) for 24 h, and cytotoxicity was analyzed by MTT assay, live-dead staining, and TC-50 was calculated. ZnO and SiO2 particles showed concentration-dependent cytotoxicity in both cell lines. In size-dependent study, ZnO particles exhibited nearly equal toxicity profile in L-132 cells while in THP-1 cells nano ZnO showed more toxicity than its micron size. The SiO2 particles showed more toxicity in their nano size than micron size in both cell lines. Human monocytes, THP-1 cells, were more sensitive towards the toxicity of both particles than human lung cells, L-132. The results highlight the difference of cytotoxicity between particle sizes and differential sensitivity of cells towards the particles of same composition. In conclusion, ZnO and SiO2 particles exhibited concentration-dependent toxicity, which was more in their nano size than micron counterpart. However, the toxic response varies depending on type of cell exposed due to differential sensitivity.