Antimicrobial polyethyleneimine-silver nanoparticles in a stable colloidal dispersion

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Colloidal stability and antimicrobial activity are crucial for silver nanoparticles (AgNPs) in biomedical applications.
• Polyethyleneimine (PEI) is a polymer used for capping nanoparticles.

Purpose of the Study:

• To synthesize and characterize PEI-capped silver nanoparticles (PEI-AgNPs).
• To evaluate the colloidal stability, antimicrobial activity, and cytotoxicity of PEI-AgNPs.

Main Methods:

• Synthesis of PEI-AgNPs using PEI and sodium borohydride (NaBH(4)) at room temperature.
• Characterization of zeta potential, particle size, and hydrodynamic cluster size.
• Assessment of antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae.
• Evaluation of cell viability to determine cytotoxic effects.

Main Results:

• PEI-AgNPs exhibited a positive zeta potential (+49 mV), ensuring colloidal stability via electrostatic repulsion.
• Particle and cluster sizes correlated with PEI and NaBH(4) concentrations.
• Both PEI-AgNPs and PEI demonstrated significant antimicrobial activity.
• Cytotoxicity was observed, confirming the need for careful PEI concentration management.

Conclusions:

• PEI-capped silver nanoparticles offer promising colloidal stability and antimicrobial efficacy.
• The concentration of PEI must be optimized to balance nanoparticle stability and minimize cytotoxicity.
• Further research is needed to fine-tune PEI levels for safe and effective biomedical applications.