Microbiologist, June 2014

Page 16


SYNTHETIC COLLOIDS with antimicrobial action

Introduction Conventional antimicrobials include antibiotics as well as natural and synthetic antiseptic agents whose molecules attack and kill microbial cells or suppress their growth. As many microbes develop resistance, treatment of infection can require doses higher than what is safely acceptable to work effectively, and calls for novel antimicrobials or alternative protection strategies.

Nanotechnology provides us with unconventional approaches for fighting microbes




June 2014

Nanotechnology provides us with unconventional approaches for fighting microbes, which do not rely on the existing pathways of antibiotic action. One possible route to address this challenge involves synthetic colloids with engineered antimicrobial action designed to target specific pathogens. Colloids are a large class of materials which contain very small particles, with sizes ranging from a few nanometres to several micrometres. Synthetic colloids with antimicrobial action can potentially have high activity at ultralow particle concentrations. There is a lot of ongoing work on colloid particles of added functionality which exhibit strong and universal antibacterial, antifungal and antiviral action towards which microbes have not been able to develop resistance. Various novel strategies have been pursued in search of antimicrobial agents based on natural as well as synthetic colloid particles. The latter include nanoparticles produced from various metals and their oxides, e.g., copper, aluminium, gold, silver, magnesium, zinc and titanium. These inorganic nanoparticles have very different mechanisms of antimicrobial activity and can retain their antimicrobial action in adverse conditions. Smaller nanoparticles generally show greater antimicrobial activity, enhanced by their high surface area of contact with the target microbial cells.