Toxicity of cadmium sulfide (CdS) nanoparticles against Escherichia coli and HeLa cells

• Published in: Journal of hazardous materials Vol. 260; pp. 1073 - 1082
• Main Authors: Hossain, Sk Tofajjen, Mukherjee, Samir Kumar
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2013; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Atomic force microscopy; Bacteria; Bacterial morphology; Bacterial Proteins - metabolism; Cadmium Compounds - chemistry; Cadmium Compounds - toxicity; Cadmium sulfides; CdS nanoparticles toxicity; Cell division; Cell Division - drug effects; Cell Line, Tumor; Cell Membrane - drug effects; Chemical engineering; Cytoskeletal Proteins - metabolism; Dose-Response Relationship, Drug; Escherichia coli; Escherichia coli - drug effects; Escherichia coli Proteins - metabolism; Exact sciences and technology; Exposure; Gene Expression Profiling; Gene Expression Regulation, Bacterial - drug effects; Gene Expression Regulation, Neoplastic - drug effects; HeLa cell structure; HeLa Cells; Humans; Membrane Proteins - metabolism; Microscopy, Atomic Force; Microscopy, Electron, Transmission; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - toxicity; Oxidative Stress; Pollution; Reactive Oxygen Species; Reactors; Spectrometry, Fluorescence; Sulfides - chemistry; Sulfides - toxicity; Time Factors; Toxicity; Viability; X-Ray Diffraction; Cell division; CdS nanoparticles toxicity; Oxidative stress; HeLa cell structure; Bacterial morphology; Atomic force microscopy; Correlation; Nanoparticle; Segregation; Toxicity; Escherichia coli; Ultrafine particle; Transmission electron microscopy; Correlation analysis; Morphology; Aerosols; Bacteria; Air pollution; Oxidation; Enterobacteriaceae
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.07.005

•Toxic effect of CdS NPs on the growth and cell division in E. coli was studied.•CdS NPs affected cell surface topology and cell division.•Downregulation of both FtsZ and FtsQ was observed due to NPs exposure.•CdS NPs affected HeLa cell morphology with fragmented nuclei.•All such effects might be due to elevated oxidative stress. The present study endeavours to assess the toxic effect of synthesized CdS nanoparticles (NPs) on Escherichia coli and HeLa cells. The CdS NPs were characterized by DLS, XRD, TEM and AFM studies and the average size of NPs was revealed as ∼3nm. On CdS NPs exposure bacterial cells changed morphological features to filamentous form and damage of the cell surface was found by AFM study. The expression of two conserved cell division components namely ftsZ and ftsQ in E. coli was decreased both at transcriptional and translational levels upon CdS NPs exposure. CdS NPs inhibited proper cell septum formation without affecting the nucleoid segregation. Viability of HeLa cells declined with increasing concentration of CdS NPs and the IC50 value was found to be 4μg/mL. NPs treated HeLa cells showed changed morphology with condensed and fragmented nuclei. Increased level of reactive oxygen species (ROS) was found both in E. coli and HeLa cells on CdS NPs exposure. The inverse correlation between declined cell viabilities and elevated ROS level suggested that oxidative stress seems to be the key event by which NPs induce toxicity both in E. coli and HeLa cells.