Bioconjugated nanoparticles for attachment and penetration into pathogenic bacteria

As an antimicrobial agent, silver nanoparticles functionalized with both bacitracin A and polymyxin E (AgNPs-BA&PE) were designed and synthesized with complementary antibacterial functions to act against gram-positive and gram-negative bacteria. AgNPs-BA&PE could easily get attached and penetrate into the bacterial cell membrane through surface-immobilized BA and PE with a membrane target, resulting in up to 10-fold increase in the antibacterial activity, without the emergence of bacterial resistance. Analysis of the antimicrobial mechanism confirmed that the synthesized nanoparticles caused disorganization of the bacterial cytomembrane and leakage of cytoplasmic contents. This antimicrobial agent with better biocompatibility can promote healing of infected wounds, and has promising and useful applications in biomedical devices and antibacterial control systems. (C) 2013 Elsevier Ltd. All rights reserved.