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Paing YMM, Eom Y, Song GB, Kim B, Choi MG, Hong S, Lee SH. Neurotoxic effects of polystyrene nanoplastics on memory and microglial activation: Insights from in vivo and in vitro studies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171681. [PMID: 38490422 DOI: 10.1016/j.scitotenv.2024.171681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/05/2024] [Accepted: 03/10/2024] [Indexed: 03/17/2024]
Abstract
Nanoplastics, arising from the fragmentation of plastics into environmental pollutants and specialized commercial applications, such as cosmetics, have elicited concerns due to their potential toxicity. Evidence suggests that the oral ingestion of nanoplastics smaller than 100 nm may penetrate the brain and induce neurotoxicity. However, comprehensive research in this area has been hampered by technical challenges associated with the detection and synthesis of nanoplastics. This study aimed to bridge this research gap by successfully synthesizing fluorescent polystyrene nanoplastics (PSNPs, 30-50 nm) through the incorporation of IR-813 and validating them using various analytical techniques. We administered PSNPs orally (10 and 20 mg/kg/day) to mice and observed that they reached brain tissues and induced cognitive dysfunction, as measured by spatial and fear memory tests, while locomotor and social behaviors remained unaffected. In vitro studies (200 μg/mL) demonstrated a predominant uptake of PSNPs by microglia over astrocytes or neurons, leading to microglial activation, as evidenced by immunostaining of cellular markers and morphological analysis. Transcriptomic analysis indicated that PSNPs altered gene expression in microglia, highlighting neuroinflammatory responses that may contribute to cognitive deficits. To further explore the neurotoxic effects of PSNPs mediated by microglial activation, we measured endogenous neuronal activity using a multi-electrode array in cultured hippocampal neurons. The application of conditioned media from microglia exposed to PSNPs suppressed neuronal activity, which was reversed by inhibitors of microglial activation. Our findings offer detailed insights into the mechanisms by which nanoplastics damage the brain, particularly emphasizing the potential environmental risk factors that contribute to cognitive impairment in neurodegenerative diseases.
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Affiliation(s)
- Yunn Me Me Paing
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Yunkyung Eom
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Gyeong Bae Song
- Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Bokyung Kim
- Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Myung Gil Choi
- Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Sungguan Hong
- Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
| | - Sung Hoon Lee
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea.
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Djapovic M, Apostolovic D, Postic V, Lujic T, Jovanovic V, Stanic-Vucinic D, van Hage M, Maslak V, Cirkovic Velickovic T. Characterization of Nanoprecipitated PET Nanoplastics by 1H NMR and Impact of Residual Ionic Surfactant on Viability of Human Primary Mononuclear Cells and Hemolysis of Erythrocytes. Polymers (Basel) 2023; 15:4703. [PMID: 38139955 PMCID: PMC10747210 DOI: 10.3390/polym15244703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Manufactured nanoplastic particles (NPs) are indispensable for in vitro and in vivo testing and a health risk assessment of this emerging environmental contaminant is needed. The high surface area and inherent hydrophobicity of plastic materials makes the production of NPs devoid of any contaminants very challenging. In this study, we produced nanoprecipitated polyethylene terephthalate (PET) NPs (300 nm hydrodynamic diameter) with an overall yield of 0.76%. The presence of the ionic surfactant sodium dodecyl sulfate (SDS) was characterized by 1H NMR, where the relative ratio of NP/surfactant was monitored on the basis of the chemical shifts characteristic of PET and SDS. For a wide range of surfactant/NP ratios (17:100 to 1.2:100), the measured zeta potential changed from -42.10 to -34.93 mV, but with an NP concentration up to 100 μg/mL, no clear differences were observed in the cellular assays performed in protein-rich media on primary human cells. The remaining impurities contributed to the outcome of the biological assays applied in protein-free buffers, such as human red blood cell hemolysis. The presence of SDS increased the NP-induced hemolysis by 1.5% in protein-rich buffer and by 7.5% in protein-free buffer. As the size, shape, zeta potential, and contaminants of NPs may all be relevant parameters for the biological effects of NPs, the relative quantification of impurities exemplified in our work by the application of 1H NMR for PET NPs and the ionic surfactant SDS could be a valuable auxiliary method in the quality control of manufactured NPs.
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Affiliation(s)
- Milica Djapovic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Danijela Apostolovic
- Immunology and Allergy Division, Center for Molecular Medicine, Department of Medicine Solna, Karolinska Institutet, 171 77 Stockholm, Sweden; (D.A.); (M.v.H.)
| | - Vojislava Postic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Tamara Lujic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Vesna Jovanovic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Dragana Stanic-Vucinic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Marianne van Hage
- Immunology and Allergy Division, Center for Molecular Medicine, Department of Medicine Solna, Karolinska Institutet, 171 77 Stockholm, Sweden; (D.A.); (M.v.H.)
| | - Veselin Maslak
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Tanja Cirkovic Velickovic
- University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11158 Belgrade, Serbia
- Serbian Academy of Sciences and Arts, Knez Mihajlova 35, 11102 Belgrade, Serbia
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