Antimicrobial Activity of Silver Nanoparticles in Polycaprolactone Nanofibers against Gram-Positive and Gram-Negative Bacteria

Drug-resistance infections have increased extremely quickly in the past years, emerging as a serious health problem in the world. Novel and better antimicrobial agents are still being developed to control associated microorganisms. However, this still represents a great challenge for antimicrobial agents. The aim of this study was to prepare and characterize polycaprolactone nanofibers containing silver nanoparticles and to evaluate their antimicrobial properties against various Gram-positive and negative microorganisms associated with drug-resistance infections. Polycaprolactone-silver fibers (PCL-AgNPs) were prepared by reduction in situ method of Ag+ ions by N,N-dimethylformamide in tetrahydrofuran solution with the simple addition of polycaprolactone in the solution for electrospinning. The results of dynamic light scattering and UV–visible spectroscopy showed the presence of silver nanoparticles with diameters of around 10–15 nm. STEM and energy dispersive X-ray spectroscopy confirmed the presence of silver agglomerates distributed over the surface of nanofibers. All PCL-AgNPs nanofibers samples showed good and specific antibacterial effect despite low silver concentration; therefore, this activity might depend on particular microbiological and cell structure characteristics as well as concentration of silver on the nanofibers. PCL-AgNPs nanofibers might have a high potential for medical applications focused on the control of drug-resistance infections.