Bioconjugated nanoparticles for attachment and penetration into pathogenic bacteria

Area of Science:

• Nanotechnology
• Microbiology
• Biochemistry

Background:

• Bacterial infections pose a significant threat, necessitating novel antimicrobial strategies.
• Conventional antibiotics face challenges like resistance and limited efficacy against diverse bacterial strains.
• Silver nanoparticles (AgNPs) offer broad-spectrum antimicrobial properties, but their functionalization can enhance targeted delivery and efficacy.

Purpose of the Study:

• To design and synthesize silver nanoparticles functionalized with bacitracin A and polymyxin E (AgNPs-BA&PE).
• To evaluate the enhanced antibacterial activity of AgNPs-BA&PE against both gram-positive and gram-negative bacteria.
• To investigate the antimicrobial mechanism and assess biocompatibility for potential biomedical applications.

Main Methods:

• Synthesis of silver nanoparticles functionalized with bacitracin A and polymyxin E.
• Assessment of antibacterial activity through quantitative analysis, comparing functionalized AgNPs with controls.
• Microscopic analysis to investigate the mechanism of bacterial cell membrane disruption.
• Biocompatibility assays to evaluate the agent's safety for host tissues.

Main Results:

• The synthesized AgNPs-BA&PE demonstrated significantly enhanced antibacterial activity, up to a 10-fold increase, against both gram-positive and gram-negative bacteria.
• The functionalized nanoparticles effectively attached to and penetrated bacterial cell membranes, leading to cytomembrane disorganization and cytoplasmic leakage.
• No emergence of bacterial resistance was observed with the AgNPs-BA&PE treatment.
• The antimicrobial agent exhibited favorable biocompatibility, indicating potential for safe application in infected wound healing.

Conclusions:

• Functionalization of silver nanoparticles with bacitracin A and polymyxin E creates a potent antimicrobial agent with complementary functions against a broad spectrum of bacteria.
• The enhanced efficacy is attributed to targeted cell membrane interaction and disruption, bypassing common resistance mechanisms.
• AgNPs-BA&PE show significant promise for applications in treating infected wounds, developing advanced biomedical devices, and implementing effective antibacterial control systems.