Electrospun polymer-quaternary ammonium compound nanofibers for dynamic disinfection of bacteria

Electrospun fibers have gained attention in recent years for their high surface-to-volume ratio, tunable porosity, and capacity to incorporate other functional materials. While commonly utilized in areas like air and water filtration and biomedical applications, these fibers could support microbial growth depending on other external conditions, such as temperature, humidity, and nutrient presence. As a result, recent advances on research focus on imparting antimicrobial activity to the electrospun fibrous material.

This study involved blending polymethylmethacrylate (PMMA) with cetyltrimethylammonium bromide (CTAB), a quaternary ammonium compound, in varying concentrations before electrospinning the solution into nanofibers. Their composition was analyzed through Fourier-transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) techniques. The antibacterial efficacy of the fibers was assessed against Staphylococcus aureus and Escherichia coli over contact times ranging from 1 to 60 minutes, using plate count assays based on AATCC Test Method 100-1999. The release behavior of CTAB was studied through spectrophotometric analysis following Hach Method 8773.

Results showed increased antibacterial performance with higher CTAB concentrations and longer contact times, achieving up to 4.5-log reduction against S. aureus and 1.6-log reduction against E. coli. Release kinetics revealed a biphasic pattern comprised of an initial burst followed by a slower release and linked to rising CTAB concentration at the fiber interface. These findings demonstrate the capability of PMMA-CTAB electrospun nanofibers to perform dynamic disinfection of bacteria.