Antimicrobial activity and cytotoxicity of copper/polydopamine nanocomposites

Abstract

This work showcases the fabrication, characterization, antibacterial activity, and cytotoxicity of copper/polydopamine (Cu/PDA) nanocomposites. The nanocomposites were prepared by either embedding copper nanoparticles within the matrix (Cu-PDA) or incorporating them on the surface (Cu@PDA) of PDA. Incorporating these nanoparticles (NPs) on the surface or within the matrix of PDA helps to unravel the issue of agglomeration while improving their dispersion. However, the Cu NPs tend to grow and agglomerate at high concentrations of the Cu precursor/ copper chloride (CuCl2). At low concentrations of CuCl2, the sizes and dispersion of Cu NPs were easily controlled. The nanocomposites have shown insignificant cytotoxicity towards baby hamster kidney fibroblast (BHK-21) cells. However, at high nanocomposites concentration, Cu@PDA became toxic to the cells compared to Cu-PDA. An exceptional antibacterial activity of these nanocomposites against gram-positive and gram-negative bacteria was also observed. Cu@PDA possessed more potent activity than Cu-PDA due to high NPs exposure to the bacteria.

Keywords

• Copper
• Polydopamine
• Nanocomposite
• E. coli
• S. aureus