Handling (Nano)Silver as Antimicrobial Agent: Therapeutic Window, Dissolution Dynamics, Detection Methods and Molecular Interactions

Silver is an antimicrobial agent well known since antiquity. With the emergence of multiresistant bacteria, it has come back into the focus of research, and ionic as well as nano‐sized silver have been studied in vitro and in vivo. The results are controversial, silver being discussed as the “silver bullet” or a “wolf in sheep's clothing”. A thorough search of literature from chemistry, materials and environmental science, biology and medicine led to this Review which summarizes the potential use of silver and its compounds in medicine, ongoing processes of dissolution and the different methods by which this usefulness can be evaluated. It also highlights the therapeutic window of silver, mechanistic interactions of silver and biological media as well as best practices for handling silver in a biomedical environment. This Review reflects the current knowhow and observations, and may thus give hints and guidelines to understand and interpret the observed effects. Friend or foe? Rarely has a biologically active element discussed so controversially been discussed than silver in ionic or nano form. This Review draws together literature from chemistry, materials and environmental sciences, biology and medicine to give insight into the activity and mechanism of silver in biological media, be it in contact with bacteria or cells.