Potent antibacterial nanoparticles for pathogenic bacteria

Antibiotic-resistant bacteria have emerged because of the prevalent use of Antibacterial agents. Thus, new Antibacterial agents and therapeutics that can treat Bacterial infections are necessary. Vancomycin is a potent Antibiotic. Unfortunately, some Bacterial strains have developed their resistance toward vancomycin. Nevertheless, it has been demonstrated that vancomycin-immobilized nanoparticles (NPs) are capable to be used in inhibition of the cell growth of vancomycin-resistant Bacterial strains through multivalent interactions. However, multistep syntheses are usually necessary to generate vancomycin-immobilized NPs. Thus, maintaining the Antibiotic activity of vancomycin when the drug is immobilized on the surface of NPs is challenging. In this study, a facile approach to generate vancomycin immobilized gold (Van-Au) NPs through one-pot stirring of vancomycin with aqueous tetrachloroauric acid at pH 12 and 25 °C for 24 h was demonstrated. Van-Au NPs (8.4 ± 1.3 nm in size) were readily generated. The generated Van-Au NPs maintained their Antibiotic activities and inhibited the cell growth of pathogens, which included Gram-positive and Gram-negative bacteria as well as antibiotic-resistant Bacterial strains. Furthermore, the minimum inhibitory concentration of the Van-Au NPs against bacteria was lower than that of free-form vancomycin. Staphylococcus aureus-infected macrophages were used as the model samples to examine the Antibacterial activity of the Van-Au NPs. Macrophages have the tendency to engulf Van-Au NPs through endocytosis. The results showed that the cell growth of S. aureus in the macrophages was effectively inhibited, suggesting the potential of using the generated Van-Au NPs as Antibacterial agents for Bacterial infectious diseases.

Staphylococcus aureus; antibiotics; gold nanoparticles; macrophage; pathogenic bacteria; vancomycin.