Coaxial electrospun PCL/PVA core-shell nanofibrous scaffolds with green-synthesized AgNPs for release-regulated antibacterial activity.

Abstract

This study developed coaxially electrospun polycaprolactone/polyvinyl alcohol (PCL/PVA) core-shell nanofibrous scaffolds incorporating green-synthesized silver nanoparticles (AgNPs) from Synedrella nodiflora as candidate antibacterial wound-dressing materials. The core-shell design was evaluated against a conventional blended PCL/PVA/AgNP control at the same AgNP loading to assess architecture-dependent performance. Transmission Electron Microscopy (TEM) analysis supported the formation of a distinguishable PCL/PVA core-shell structure, while Scanning Electron Microscopy (SEM) showed uniform, bead-free fibers, with diameter reduced from 332 nm to 310 nm after AgNP incorporation. Fourier Transform Infrared Spectroscopy (FTIR) analysis supported the presence of hydroxyl-containing phytochemical residues or polar functional groups associated with the green-synthesized AgNPs. Moisture management properties improved, with Overall Moisture Management Capacity (OMMC) increasing from 0.16 to 0.74 and Accumulative One-Way Transport Index (AOTI) shifting from -28.6 to 310.2, indicating improved liquid transport under MMT conditions. Thermal stability also increased, with degradation temperature rising from 378 °C to 392 °C and residual weight from 5.2% to 6.3%. Mechanical strength decreased slightly with AgNP addition, while elongation remained relatively high, showing a trade-off between strength and flexibility. UV-Vis-based apparent silver-associated release profiling showed a slower release trend for coaxial PP-3% than blended Control-3%. PP-3% exhibited the highest preliminary antibacterial activity, with inhibition zones of 22 mm against E. coli and 17 mm against S. aureus. Vero cell viability remained above 90%, indicating preliminary cytocompatibility.