Studies on interfacial interactions of TiO2 nanoparticles with bacterial cells under light and dark conditions

Bulletin of materials science

Amitava Mukherjee²  N Chandrasekaran²  Sujay Chakravarty¹  Swayamprava Dalai²  Sunandan Pakrashi²  Shamima Hussain¹ 

[1] UGC-DAE CSR, Kalpakkam Node, Kokilamedu 603 104, India$$UGC-DAE CSR, Kalpakkam Node, Kokilamedu 603 104, IndiaUGC-DAE CSR, Kalpakkam Node, Kokilamedu 603 104, India$$;Centre for Nanobiotechnology, VIT University, Vellore 632 014, India$$Centre for Nanobiotechnology, VIT University, Vellore 632 014, IndiaCentre for Nanobiotechnology, VIT University, Vellore 632 014, India$$

关键词: Cytotoxicity;    dark;    FTâ€�?�IR;    FTâ€�?�Raman;    XPS;    fluorescence spectroscopy.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The probable underlying mechanism(s) of bacterial cellâ€�?�TiO₂ nanoparticles (TiO₂ NPs) interaction in the absence of photo-irradiation has been less studied since most of the prior cytotoxicity studies focused on irradiated TiO₂. The present study draws attention to the possible role of cell surfaceâ€�?�TiO₂ NP interactions under dark conditions, through an array of spectroscopic and microscopic investigations. A dominant freshwater bacterial isolate, Bacillus licheniformis, which interacted with environmentally relevant concentrations of TiO₂ NPs (1 𝜇g/mL), was analysed and compared under both light and dark conditions. Aggregation of cells upon NP interaction and adsorption of NPs onto the cell membrane was evident from the scanning electron micrographs under both light and dark conditions. The FTâ€�?�IR and FTâ€�?�Raman spectra suggested stress response of bacterial cells by elevated protein and polysaccharide content in the cellâ€�?�NP interaction. The X-ray photoelectron spectroscopic data substantiated the reduction of titanium from Ti(IV) to Ti(III) species which might have contributed to the redox interactions on the cell surface under light as well as dark conditions. The internalization of NPs in the cytoplasm were obvious from the transmission electron micrographs. The consequent cell death/damage was confirmed through fluorescence spectroscopy and microscopy. To conclude, the current study established the substantial role of interfacial interactions in cytotoxicity of the TiO₂ NPs irrespective of the irradiation conditions.

【 授权许可】

Unknown