Imperial College London


Faculty of EngineeringDepartment of Materials

Vice-Dean (Research), Faculty of Engineering



+44 (0)20 7594 6755m.p.ryan




B338Royal School of MinesSouth Kensington Campus






BibTex format

author = {Sarkar, S and Zhang, L and Subramaniam, P and Lee, K-B and Garfunkel, E and Strickland, PAO and Mainelis, G and Lioy, PJ and Tetley, TD and Chung, KF and Zhang, J and Ryan, M and Porter, A and Schwander, S},
doi = {10.1371/journal.pone.0097304},
journal = {PLOS One},
title = {Variability in Bioreactivity Linked to Changes in Size and Zeta Potential of Diesel Exhaust Particles in Human Immune Cells},
url = {},
volume = {9},
year = {2014}

RIS format (EndNote, RefMan)

AB - Acting as fuel combustion catalysts to increase fuel economy, cerium dioxide (ceria, CeO2) nanoparticles have been used inEurope as diesel fuel additives (EnviroxTM). We attempted to examine the effects of particles emitted from a diesel engineburning either diesel (diesel exhaust particles, DEP) or diesel doped with various concentrations of CeO2 (DEP-Env) on innateimmune responses in THP-1 and primary human peripheral blood mononuclear cells (PBMC). Batches of DEP and DEP-Envwere obtained on three separate occasions using identical collection and extraction protocols with the aim of determiningthe reproducibility of particles generated at different times. However, we observed significant differences in size and surfacecharge (zeta potential) of the DEP and DEP-Env across the three batches. We also observed that exposure of THP-1 cells andPBMC to identical concentrations of DEP and DEP-Env from the three batches resulted in statistically significant differencesin bioreactivity as determined by IL-1b, TNF-a, IL-6, IFN-c, and IL-12p40 mRNA (by qRT-PCR) and protein expression (byELISPOT assays). Importantly, bioreactivity was noted in very tight ranges of DEP size (60 to 120 nm) and zeta potential (237to 241 mV). Thus, these physical properties of DEP and DEP-Env were found to be the primary determinants of thebioreactivity measured in this study. Our findings also point to the potential risk of over- or under- estimation of expectedbioreactivity effects (and by inference of public health risks) from bulk DEP use without taking into account potential batchto-batchvariations in physical (and possibly chemical) properties.
AU - Sarkar,S
AU - Zhang,L
AU - Subramaniam,P
AU - Lee,K-B
AU - Garfunkel,E
AU - Strickland,PAO
AU - Mainelis,G
AU - Lioy,PJ
AU - Tetley,TD
AU - Chung,KF
AU - Zhang,J
AU - Ryan,M
AU - Porter,A
AU - Schwander,S
DO - 10.1371/journal.pone.0097304
PY - 2014///
SN - 1932-6203
TI - Variability in Bioreactivity Linked to Changes in Size and Zeta Potential of Diesel Exhaust Particles in Human Immune Cells
T2 - PLOS One
UR -
UR -
VL - 9
ER -