caa a22 4500 445852712 CHVBK 20180317145418.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s00204-010-0608-7 doi (NATIONALLICENCE)springer-10.1007/s00204-010-0608-7 Cytotoxicity of zinc oxide (ZnO) nanoparticles is influenced by cell density and culture format [Elektronische Daten] [Boon Heng, Xinxin Zhao, Sijing Xiong, Kee Ng, Freddy Boey, Joachim Loo] A parameter that has often been overlooked in cytotoxicity assays is the density and confluency of mammalian cell monolayers utilized for toxicology screening. Hence, this study investigated how different cell seeding densities influenced their response to cytotoxic challenge with ZnO nanoparticles. Utilizing the same volume (1ml per well) and concentration range (5-40μg/ml) of ZnO nanoparticles, contradictory results were observed with higher-density cell monolayers (BEAS-2B cells) obtained either by increasing the number of seeded cells per well (50,000 vs. 200,000 cells per well of 12-well plate) or by seeding the same numbers of cells (50,000) within a smaller surface area (12-well vs. 48-well plate, 4.8 vs. 1.2cm2, respectively). Further experiments demonstrated that the data may be skewed by inconsistency in the mass/number of nanoparticles per unit area of culture surface, as well as by inconsistent nanoparticle to cell ratio. To keep these parameters constant, the same number of cells (50,000 per well) were seeded on 12-well plates, but with the cells being seeded at the edge of the well for the experimental group (by tilting the plate) to form a dense confluent monolayer, as opposed to a sparse monolayer for the control group seeded in the conventional manner. Utilizing such an experimental set-up for the comparative evaluation of four different cell lines (BEAS-2B, L-929, CRL-2922 and C2C12), it was observed that the high cell density monolayer was consistently more resistant to the cytotoxic effects of ZnO nanoparticles compared to the sparse monolayer for all four different cell types, with the greatest differences being observed above a ZnO concentration of 10μg/ml. Hence, the results of this study demonstrate the need for the standardization of cell culture protocols utilized for toxicology screening of nanoparticles, with respect to cell density and mass/number of nanoparticles per unit area of culture surface. Springer-Verlag, 2010 Cell density nationallicence Confluent nationallicence Nanoparticle nationallicence Toxicology nationallicence Viability nationallicence Zinc Oxide nationallicence Heng Boon Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Zhao Xinxin Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Xiong Sijing Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Ng Kee Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Boey Freddy Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Loo Joachim Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut Archives of Toxicology Springer-Verlag 85/6(2011-06-01), 695-704 0340-5761 85:6<695 2011 85 204 https://doi.org/10.1007/s00204-010-0608-7 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00204-010-0608-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heng Boon Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Zhao Xinxin Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Xiong Sijing Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Ng Kee Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Boey Freddy Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Loo Joachim Division of Materials Science, School of Materials Science and Engineering, Nanyang Technological University, N3-B4-W310, Nanyang Avenue, 639798, Singapore, Singapore aut NATIONALLICENCE 773 0- Archives of Toxicology Springer-Verlag 85/6(2011-06-01), 695-704 0340-5761 85:6<695 2011 85 204 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer