Unveiling new frontiers in advancements of metal oxides nanoparticles (ZnO, TiO2, CuO and Ag2O) and their hybrids for antibacterial applications: A review on mechanistic insights and toxicity
Prakash Monika, R. Hari Krishna, Anirudh Bantwal Baliga, K. Ravisagar, Rupam Sinha Roy, Kandhasamy Lalitha, S. Girish Kumar
Abstract
Antibiotic resistance is one of the emerging global health concerns, and inappropriate use of antibiotics poses an added clinical challenge. In this context, the metal oxide nanoparticles (MONPs) have been extensively studied as potential solutions for multidrug-resistant (MDR) microbes and have been regarded as the most suitable and reliable alternatives to existing antibiotics owing to their inherent antibacterial properties. However, the effects of physicochemical properties on the antibacterial activity of MONPs remain inconclusive till date. Significant concerns have been raised regarding their potential toxicity to human cells and tissues, complicating their application in clinical settings. In this focused review, various mechanisms underlying the antibacterial activity of the benchmark MONPs such as ZnO, TiO 2 , Ag 2 O, CuO and Cu 2 O are discussed. The factors influencing antibacterial activity such as size, shape, surface area, and concentration are emphasized. The diverse preparation methods and their advances are corresponding highlighted. The possible toxicity of these MONPs, including genotoxicity, cytotoxicity, neurotoxicity, immunotoxicity and ecotoxicityalongside assessing their safety profiles and antibacterial efficacy are discussed. The review provides comprehensive information on the mechanistic insights of selected MONPs that have promising antibacterial applications, while highlighting their potential toxicities and paving the way for further research on their clinical utilization.