Paper Title
Evaluation of ZnO Nanoparticles and ZnO Nanohydrogel on Horse Peripheral Blood Mononuclear Cells

The re-emergence of infectious diseases and the development of antibiotic resistance against various disease causing bacteria raise a serious threat to public health. Moreover, the continuous usage of antibiotics leads to resistance development. New strategies are essential for the development of next generation drugs to control bacterial infections. The exploitations of novel substitutes to antibiotics, especially inorganic nanoparticles have recently attracted more attention. Among the metal oxide nanoparticles, the zinc oxide nanoparticles (ZnO NPs) are the most commonly used for antibacterial properties and are an ideal alternative antibacterial agent. Although nanoparticles possess novel properties that make them available in a vast range of applications, the questions regarding their safety arise when they come in contact with the biological systems. To minimize the toxicity of ZnO NPs, we synthesized bipolymeric ZnO nanohydrogel. The size of the synthesized nanoformulation was less than 100 nm. The cytotoxicity assays were performed on cultured horse PBMC isolated from Marwari horse by density gradient centrifugation. Metabolically active cells reduced the blue color nonfluorescent resazurin dye into pink color fluorescent resorufin within 4 hr(s) of incubation and percent cytotoxicity was determined. The percentage cytotoxicity was significantly higher in ZnO NPs treated cells than the ZnO nanohydrogel. Our findings suggest that ZnO NPs are toxic to cell cultures and nanoformulation of ZnO NPs using biocompatible polymer reduced the toxicity of ZnO NPs in PBMCs of horse.