Antibacterial properties of PCL-based nanofibers loaded with ZnO nanoparticles synthesized via sol-gel method

Nanofibers have attracted increasing attention in biomedical applications owing to their high surface area, porosity, and biocompatibility, which allow them to mimic the extracellular matrix and promote cell adhesion and regeneration. In this study, zinc oxide (ZnO) nanoparticles were synthesized via the sol–gel method using zinc acetate dihydrate as a precursor and were characterized by FTIR, FESEM, and EDAX analyses. The synthesized nanoparticles exhibited an average size of 30–40 nm with uniform dispersion. These nanoparticles, along with commercial ZnO, were incorporated into polycaprolactone (PCL) nanofibers fabricated by electrospinning. The resulting nanofibers displayed diameters in the range of 250–800 nm, depending on the nanoparticle content and electrospinning conditions.

Antibacterial activity was evaluated using inhibition zone assays against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). PCL nanofibers containing sol–gel derived ZnO showed superior antibacterial efficiency, with inhibition zones up to 42 mm against S. aureus and 28 mm against E. coli, compared with nanofibers containing commercial ZnO. The enhanced activity is attributed to the smaller size, higher surface reactivity, and homogeneous distribution of sol–gel ZnO nanoparticles. These findings highlight the potential of sol–gel ZnO/PCL nanofibers as advanced antibacterial scaffolds for biomedical applications.