Silver Nanoparticles: A Novel Antimicrobial Agent

Nanomaterials show unique changes in physical, chemical, and biological properties compared to macroscaled counterparts and are considered as providing solutions to technological and environmental challenges in the areas of catalysis and medicine. Metals such as gold, silver, and copper have been used mostly for the synthesis of stable dispersions of nanoparticles. Silver nanoparticles in particular are highlighted in the field of medicine microbiology due to their potent antimicrobial activities. Therefore, synthesis of silver nanoparticles for applications has received continued interest.Recent study shows that silver nanoparticles have potent antimicrobial activities via a variety mechanisms: membrane disruption, apoptosis and synergy. Due to the interaction with membranes, silver nanoparticles induce the membrane disruption in fungal cells. Also, the increase of hydroxyl radicals and mitochondrial dysfunction are crucial factors in silver nanoparticles-induced apoptosis. Interestingly, silver nanoparticles also trigger apoptotic cell death in bacteria, showing DNA fragmentation and phosphatidylserine exposure as causes of apoptosis. Moreover, with synergistic effect, silver nanoparticles increase the antibacterial capacity of conventional drugs, which confronts the problem of resistance and inhibits the formation of biofilms. Considering these mechanisms and effects on microorganisms, silver nanoparticles can be developed as a novel antimicrobial agent.