Antimicrobial peptide-modified silver nanoparticles for enhancing the antibacterial efficacy

Area of Science:

• Biomaterials Science
• Nanotechnology
• Infectious Diseases

Background:

• Antibiotic-resistant bacteria pose a significant global health risk.
• Development of novel antimicrobial strategies is crucial to combat rising resistance.
• Silver nanoparticles (AgNPs) possess inherent antimicrobial properties but require functionalization for enhanced efficacy and targeted delivery.

Purpose of the Study:

• To develop and characterize multifunctional peptide (MFP)-coated silver nanoparticles (MFP@AgNPs) for enhanced antibacterial applications.
• To evaluate the in vitro and in vivo antibacterial efficacy of MFP@AgNPs against Gram-positive and Gram-negative bacteria, particularly multidrug-resistant Acinetobacter baumannii (MDR-AB).
• To assess the potential of MFP@AgNPs as a safer and more effective alternative to bare AgNPs.

Main Methods:

• Synthesis and characterization of MFP@AgNPs using UV-vis spectrophotometry, zeta potential analysis, CD spectroscopy, ATR-FTIR, and TEM.
• Determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against various bacterial strains.
• In vitro evaluation of antibacterial activity, including cell membrane damage assessment via SEM.
• In vivo efficacy studies using a mouse model infected with MDR-AB.

Main Results:

• MFP@AgNPs were successfully synthesized and characterized, demonstrating stability and specific peptide adsorption.
• MFP@AgNPs exhibited broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria.
• MFP@AgNPs showed significantly enhanced killing of MDR-AB compared to bare AgNPs, with faster action and improved efficiency.
• SEM analysis indicated that MFP@AgNPs-1 induce bacterial cell disruption through membrane damage.
• In vivo studies confirmed the superior antibacterial performance of MFP@AgNPs-1 against MDR-AB infections.
• MFP@AgNPs demonstrated reduced cytotoxicity compared to bare AgNPs.

Conclusions:

• MFP@AgNPs represent a promising multifunctional nanomaterial for combating antibiotic-resistant bacteria.
• The developed MFP@AgNPs enhance antibacterial activity and reduce AgNP cytotoxicity, offering a potential therapeutic strategy against MDR-AB.
• This study provides a foundation for the clinical translation of peptide-functionalized nanoparticles in infectious disease treatment.