Size Attenuated Copper Doped Zirconia Nanoparticles Enhances In Vitro Antimicrobial Properties

Biofilm formation hinders the activity of antimicrobial drugs at the site of infections and any agent that can act on both Gram-positive and Gram-negative bacteria by inhibiting the bacterial growth and rupturing the biofilm is needed to manage infection. In the present study, we have synthesized zirconia nanoparticles (ZrO2 NPs) and copper doped zirconia nanoparticles (Cu-ZrO2 NPs) and characterized them using dynamic light scattering, X-ray diffractometry, and scanning electron microscopy (SEM). The size of the Cu-ZrO2 NPs drastically reduced compared to ZrO2 NPs, and the antimicrobial activity was studied against Gram-positive bacteria (Lactobacillus sp.) and Gram-negative bacteria (Pseudomonas aeruginosa), respectively. The synthesized Cu-ZrO2 NPs showed superior inhibitory action against Lactobacillus sp. compared to ZrO2 NPs, due to the negatively charged cell wall of Lactobacillus sp., which could attract readily the positively charged Cu-ZrO2 NPs, thereby inhibiting its activity. The biocompatibility was tested using XTT assay in FL cells, and the results demonstrated that Cu-ZrO2 NPs were nontoxic to mammalian cells. Hence, it could be proposed that the synthesized Cu-ZrO2 NPs possess possible biomedical applications and can be used as antibacterial agents without causing toxicity in mammalian cells.