Towards understanding the antibacterial activity of Ag nanoparticles: electron microscopy in the analysis of the materials-biology interface in the lung

Bacterial infections of the pulmonary system are increasing. With almost half of today's infections being caused by strains of bacteria that are resistant to existing conventional antibiotics, there is an urgent need for the development of novel therapeutic platforms. Silver nanoparticles (AgNPs) have been receiving increasing attention due to their unique antibacterial properties, and whilst the biological efficacy of silver is well known, the mechanisms by which AgNPs degrade within cells and how these processes correlate to their bioreactivity are poorly understood. This review summarises the current knowledge on the bactericidal pathways of AgNPs and discusses the challenges to be faced before we are able to develop efficient and safe antibacterial agents for the treatment of bacterial infections in the lung.