The electrospinning of a polymer melt is an interesting process for medical applications because it eliminates the cytotoxic effects of solvents in the electrospinning solution. Wound dressings made from thermoplastic polyurethane (TPU), particularly as a porous structured electrospun membrane, are currently the focus of scientific and commercial interest. In this study, we developed a functionalized fibrillar structure as a novel antibacterial wound-dressing material with the melt-electrospinning of TPU. The surface of the fibers was modified with poly(ethylene glycol) (PEG) and silver nanoparticles (nAg's) to improve their wettability and antimicrobial properties. TPU was processed into a porous, fibrous network of beadless fibers in the micrometer range (4.89 +/- 0.94 m). The X-ray photoelectron spectroscopy results and scanning electron microscopy images confirmed the successful incorporation of nAg's onto the surface of the fiber structure. An antibacterial test indicated that the PEG-modified nAg-loaded TPU melt-electrospun structure had excellent antibacterial effects against both a Gram-positive Staphylococcus aureus strain and Gram-negative Escherichia coli compared to unmodified and PEG-modified TPU fiber mats. Moreover, modification with nAg's and PEG increased the water-absorption ability in comparison to unmodified TPU. The cell viability and proliferation on the unmodified and modified TPU fiber mats were investigated with a mouse fibroblast cell line (L929). The results demonstrate that the PEG-modified nAg-loaded TPU mats had no cytotoxic effect on the fibroblast cells. Therefore, the melt-electrospun TPU fiber mats modified with PEG and nAg have the potential to be used as antibacterial, humidity-managing wound dressings. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40132.