478227 Cell Recoverability after Exposure to Complex Engineered Nanomaterials
CELL RECOVERABILITY AFTER EXPOSURE TO COMPLEX ENGINEERED NANOMATERIALS
Julie Hartz, Dr. Götz Veser, Dr. Ipsita Banerjee, Sharlee Mahoney, Thomas Richardson
Department of Chemical Engineering
University of Pittsburgh, PA, USA
Over the past decade, the use of nanoparticles (NPs) and complex engineered nanomaterials (CENs) in both consumer products and industrial applications has been exponentially increasing. They show great potential in many sustainable applications such as improving solar panel efficiency1 and desalination processes2. NPs are desirable due to their unique physical and chemical properties which differ from their bulk forms. For example, in its bulk form, elemental gold is yellow and chemically inert while NP gold is red and chemically reactive with favorable catalytic properties3. However, despite their significant promise, NPs could have unforeseen, detrimental health effects on humans and the environment due to their unique properties. Current environmental and health regulations regarding NPs treat them as identical to their bulk substances. Yet, it is undesirable to simply stop using NPs because of possible toxicity risks. Therefore, the development of robust, sustainable testing in the field of nanotoxicity is crucial for the safety of consumers as well as the safety of the environment.
Previous studies in our lab investigated the effect of Ni/SiO2 CENs on cell metabolism because they are widely used catalysts composed of a toxic metal (Ni) and nontoxic support (SiO2). We compared the toxic effects of CENs to those of NiCl2, a metal salt that produces free Ni2+ ions in solution. Both materials caused metabolism to decrease with increasing exposure time. However, when the exposure was removed, we observed an interesting difference in the long-term toxic effects from the two materials: cell metabolisms of those exposed to free Ni2+ ions returned to full functionality, while those exposed to CENs did not recover4. These results motivated us to further investigate cell recoverability after CEN exposure.
For the present study, in order to determine why cells could not recover, we examined CEN uptake patterns. It was important to determine whether cells were taking up the CENs, and if so, whether the cells have the ability to expel them. To do so, cells were cultured on Transwell inserts that allowed us to expose them to fluorescently tagged CENs for a given time, and then relocate them to a NP-free environment, taking samples during- and post-exposure using flow cytometry. Initial results suggested that the cells do take up the NPs, but cannot expel them during the recovery period which explains why the cells cannot recover.
1. Nakayama, K. et al., Plasmonic nanoparticle enhanced light absorption in GaAs solar cells. Applied Physics Letters (2008): Lett. 93. Web.
2. Ling, Ming Ming. Tai-Shung Chung. Desalination process using super hydrophilic nanoparticles via forward osmosis intergrated with ultrafiltration regeneration. Desalination (2011): Vol. 278, Issues 1-3. Pg. 194-202. Web.
3. Love, S. A., et al., Assessing Nanoparticle Toxicity. Annual Review of Analytical Chemistry, 5.1 (2012): 181-205. Web.
4. Mahoney, et al., The Developmental Toxicity of Complex Silica-Embedded Nickel Nanoparticles Is Determined by Their Physicochemical Properties, PLOS ONE, 2016. 11(3): p.e0152010.
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