Fabrication and Characterization of Electrospun Keratin Mats with Echinacea purpurea L. and Biosynthesized Silver Nanoparticles

This study presents the development of antibacterial electrospun nanofibrous mats composed of keratin and polyethylene oxide, incorporating <i>Echinacea purpurea</i> L. (<i>EchP</i>) and green-synthesized silver nanoparticles (<i>bio</i>AgNPs) produced using <i>EchP</i> extract. The successful synthesis of <i>bio</i>AgNPs was confirmed by colorimetric analysis, FTIR, XRD, and TEM. In vitro assays demonstrated antibacterial activity against both Gram-positive and Gram-negative bacteria at ~0.6 µg/mL. Keratin, extracted from sheep wool, retained partial native structure, supporting biocompatibility and cellular regeneration. Incorporation of <i>EchP</i> or <i>bio</i>AgNPs reduced solution viscosity by 25-45%, significantly affecting mat morphology and shifting fiber diameters toward the 50-100 nm range. Quantitative phytochemical analysis, conducted via UV-Vis spectrophotometry, showed 2-3 times higher release of tannins and phenolic compounds compared to hydroxycinnamic acid derivatives and flavonoids. Keratin electrospun mats with <i>bio</i>AgNPs exhibited about 1.5-fold lower polyphenol release, confirming the dual role of polyphenols as electron donors in Ag⁺ bioreduction and as stabilizers.