Differential toxicity of rod and spherical zinc oxide nanoparticles on human peripheral blood mononuclear cells

The cytotoxic and genotoxic potential of rod and spherical zinc oxide nanoparticles (ZnO NPs) were evaluated on human peripheral blood mononuclear cells (PBMCs). Their sizes and shapes were determined by Transmission electron microscopy (TEM) and physical characterizations were done by X-ray diffraction (XRD) and Dynamic light scattering (DLS). The cytotoxic potential of rod ZnO NPs was greater than spherical ZnO NPs when applied to PBMCs and was limited to the proliferative lymphocytes. Rod ZnO NPs produced more reactive oxygen species (ROS) compared to spherical ones. Additionally rod ZnO NPs induced significant DNA damage to PBMCs as revealed by cytokinesis block micronucleus (CBMN) assay and comet assay. On the other hand UV absorption property was enhanced in case of spherical ZnO NPs compared to rod ZnO NPs. Thus, present study implicates the shape dependent differential application of ZnO NPs in our daily life.