Nano-Adjuvant : New Ray of Hope against Anti-Microbial Resistance

Abstract

Nano-particles derived from heavy metal compounds with or without weak antimicrobial action, always express accentuated antimicrobial action in-vitro. Of these, nano silver particles (AgNPs) have been extensively studied, though limitedly used for infection control as topical applications on burn wound or surface ulcers only. Antimicrobial actions of ionic silver mediate through coagulation of some cell proteins, structural changes in cell wall and cell membrane, binding to bacterial DNA and interaction with thiol group proteins in cell and respiratory enzymes, resulting cell distortion and death. AgNPs are formed by physical transformation into energized smaller aggregations of silver molecules in presence of suitable reducing and stabilizing polymeric surfactants. Greater antibacterial effect of AgNPs are partly due to release of excess ionic silver inside cells but mostly due to closer interactions of charged tiny particles to cell surface, intercalation between DNA bases and destabilization of cell wall and ribosome. The "bonus antimicrobial effect" of AgNPs is expected to be resistance-proof by way of bacterial molecular adaptation. Universal synergism of AgNPs with conventional antibiotics is also expected due to its damaging effects of different target sites. By our in-vitro study this has been demonstrated and prompts us to test it as a sharp weapon against superbugs, which can restrain bacteria from resistant development. Thus nano-antibiotics may play very important supportive role to combat superbug.