Short ZnO Nanofiber-Integrated Electrospun Nanofibrous Scaffolds as Advanced Antibacterial Wound Dressings

Abstract

Infections remain one of the most critical challenges in wound healing, necessitating advanced biomaterials that combine effective antibacterial activity with controlled physicochemical properties. In this study, zinc oxide short nanofibers (ZnO SNFs) were introduced as antibacterial nanofillers into electrospun poly(lactic acid) (PLA) nanofibrous scaffolds for wound-dressing applications. Unlike conventional spherical nanoparticles or nanoflowers, ZnO SNFs were fabricated via electrospinning followed by calcination and ultrasound-assisted fragmentation, yielding a shortened anisotropic nanostructure. The formation and integration of SNFs within the PLA nanofiber (NF) matrix were confirmed by FESEM, while XRD analysis revealed the enhanced crystallinity of the nanocomposite scaffold. The incorporation of SNFs had no significant impact on the thermal transitions or chemical structure of the PLA NF scaffolds. Increasing ZnO SNF loading gradually enhanced surface hydrophilicity while maintaining excellent cytocompatibility across all loading levels. PLA/ZnO SNF scaffolds supported L929 fibroblast adhesion and maintained cell viability above 70%. Notably, antibacterial activity demonstrated a nonmonotonic response to ZnO SNF loading, with the lowest loading (1% w/w) exhibiting the highest activity. At 6 h, PLA/ZnO-1 SNFs achieved bacterial kill values exceeding 99.99% against both Escherichia coli and Staphylococcus aureus, whereas higher SNF loadings showed lower antibacterial activity. Overall, incorporating ZnO SNFs into PLA NF matrices offers a promising route to functional antibacterial wound-dressing materials.