Novel antibacterial electrospun mats based on poly(d,l-lactide) nanofibers and zinc oxide nanoparticles

This investigation addresses the morphological, mechanical, and antibacterial evaluation of nanocomposite mats based on poly(d,l-lactide) nanofibers with different zinc oxide nanoparticles (nano-ZnO) concentration, that were elaborated by two techniques, i.e., electrospinning of polymer/ZnO solutions and the combination of electrospinning of polymer solutions with electrospraying of nano-ZnO dispersions. The analysis of the precursory solutions was carried out in order to understand the achieved morphology of nanofibers. The obtained poly(d,l-lactide)/ZnO fibrous mats showed a uniform morphology with an average porosity ca. 55 % and average pore size around 45 mu m. The presence of ZnO nanoparticles increased the toughness of the mats, and an optimal nano-ZnO concentration (i.e., 3 wt%) was observed at which the tensile strength and Young's modulus could be improved. Concerning to the antibacterial properties, a relatively low concentration of nanoparticles provoked a growth inhibition of the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The mats have potential features for use as antimicrobial wound dressings.