Heteroagglomeration of zinc oxide nanoparticles with clay mineral modulates the bioavailability and toxicity of nanoparticle in Tetrahymena pyriformis.
The extensive use of zinc oxide nanoparticles (ZnO NPs) in cosmetics, sunscreens and healthcare products increases their release in the aquatic environment. The present study explored the possible interaction of ZnO NPs with montmorillonite clay minerals in aqueous conditions. An addition of ZnO NPs on clay suspension significantly (p<0.05) increases the hydrodymic size of clay particles from 1652±90nm to 2158±13nm due to heteroagglomeration. The electrokinetic measurements showed a significant (p<0.05) difference in the electrophoretic mobilities of bare (-1.80±0.03μmcm/Vs) and ZnO NPs-clay association (-1.37±0.03μmcm/Vs) that results to the electrostatic interaction between ZnO NPs and clay particles. The attenuated total reflectance Fourier transform infrared spectroscopy analysis of ZnO NPs-clay association demonstrated the binding of ZnO NPs with the Si-O-Al region on the edges of clay particles. The increase in size of ZnO NPs-clay heteroagglomerates further leads to their sedimentation at 24h. Although, the stability of ZnO NPs in the clay suspension was decreased due to heteroagglomeration, but the bioavailability and toxicity of ZnO NPs-clay heteroagglomerates in Tetrahymena pyriformis was enhanced. These observations provide an evidence on possible mechanisms available in natural environment that can facilitate nanoparticles entry into the organisms present in lower trophic levels of the food web.
Division of Biological & Life Sciences, School of Arts & Sciences, Ahmedabad University, University Road, Navrangpura, Ahmedabad, 380009 Gujarat, India; Nanotherapeutics & Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, 31- M.G. Marg, P.O. Box - 80, Lucknow 226001, U.P., India.
Govind Sharan
GS
Gupta
Division of Biological & Life Sciences, School of Arts & Sciences, Ahmedabad University, University Road, Navrangpura, Ahmedabad, 380009 Gujarat, India.
Violet Aileen
VA
Senapati
Nanotherapeutics & Nanomaterial Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, 31- M.G. Marg, P.O. Box - 80, Lucknow 226001, U.P., India. Electronic address: alokdhawan@iitr.res.in.
Alok
A
Dhawan
Division of Biological & Life Sciences, School of Arts & Sciences, Ahmedabad University, University Road, Navrangpura, Ahmedabad, 380009 Gujarat, India. Electronic address: rishishanker@gmail.com.
Rishi
R
Shanker
D000538:Aluminum Silicates; D001546:Bentonite / Q000737:chemistry / Q000378:metabolism*; D002470:Cell Survival; D000077215:Clay; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D013769:Tetrahymena pyriformis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015034:Zinc Oxide / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*
D000538:Aluminum Silicates; D017382:Reactive Oxygen Species; D001546:Bentonite; D015034:Zinc Oxide; D000077215:Clay
Ecotoxicity; Montmorillonite clay; Protozoa; ROS