Zinc oxide nanoparticle induced neurotoxic potential upon interaction with primary astrocytes

As obvious from the basic prerequisite of any particle in nanoscale, Zinc oxide nanoparticles (ZnO NPs) possess numerous tunable properties distinct from their bulk formulations. Emerging innovations in various sectors of nanotechnology are exploiting ZnO NPs largely. This inturn picks up the occasions of human exposure irrespective of the application fields. Although the platform of nanotoxicology has been garnished with nano-bio interaction studies using different cell lines, a few are existing so far comprising primary cells which symbolize realistic in vivo environment. The present study addresses the neurotoxic potential of ZnO NPs using primary astrocytes isolated from post-natal 0-2 day old rat pups. Cells were cultured and maintained in DMEM F12 followed by purification. ZnO NPs generated by wet chemical method was then characterized both physico chemically and biologically. All of the techniques confirmed homogenous distribution of NPs and ensured enough colloidal stability. Bio-nano interaction studies commence on cell viability assays (MTT and NRU) and both of which confirmed dose and time dependent cytotoxicity. Alterations within cellular morphology, cytoskeletal arrangement, lysosomal stability, mitochondrial membrane potential (MMP) and caspase activation were evaluated by standardized techniques. All of the assays substantiated significant toxic consequences in astrocytes with characteristic hall marks. Apoptotic cell death was noted without any deformations of nuclear material. A comparative toxicity study using ZnO NPs, ZnCl₂ and ZnO bulk form was performed which confirmed nanospecific toxicity of ZnO NPs. Overall study evidently provide cautious information that ZnO NPs is capable of eliciting serious neuronal tissue damages which can turn out to be fatal during prolonged exposure.