Functional electrospun cellulosic nanofiber mats for antibacterial bandages

Abstract

Functionalization of cellulosic nanofibers was established to develop antibacterial bandages. The functionalization was conducted through preparation of carboxymethyl cellulose (CMC) containing different metal nanoparticles (MNPs) such as copper nanoparticles (CuNPs), iron nanoparticles (FeNPs) and zinc nanoparticles (ZnNPs). Fourier Transform Infrared spectroscopy was used to characterize CMC containing MNPs and scanning electron microscopy coupled with high energy dispersive X-ray (SEM-EDX) to study the surface morphology of CMC with and without MNPs. Furthermore, back scattering electron detector was used to show the position of metal nanoparticles on the microcrystalline CMC. In addition, UV-visible spectroscopy was used to confirm MNPs formation. Nanofiber mats of CMC containing MNPs were synthesized using electrospinning technique. Surface morphology of electrospun CMC containing MNPs was characterized using SEM. The obtained data revealed that elctrospun CMC nanofibers containing MNPs were smooth and uniformly distributed without bead formation. The average fiber diameters were in the range of 150 to 200 nm and the presence of MNPs in the nanofiber did not affect the size of the electrospun nanofiber diameter. Transmission electron microscopy (TEM) images displayed that MNPs were existed inside and over the surface of the electrospun nanofibers without any agglomeration. The average particle diameters of MNPs were 29-39 nm for ZnNPs, 23-27 nm for CuNPs and 22-26 nm for FeNPs. Moreover, Water uptake of electrospun nanofiber mats and the release of MNPs from nanofibers were evaluated. Nevertheless, electrospun CMC nanofibers containing MNPs had an excellent antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus.