Preparation, characterization and antibacterial evaluation of PLA/ZnO nanofiber membranes loaded with thymol by coaxial electrospinning

In this study, a novel nanofiber material possessing antibacterial and antioxidant properties was fabricated through coaxial electrospinning, utilizing polylactic acid (PLA), thymol (THY), and nano zinc oxide (ZnO) as the raw materials. THY and ZnO was used to endows the membranes with good antibacterial and antioxidant properties. The surface morphology of the PLA/Z@T nanofiber membrane was characterized using scanning electron microscopy (SEM). Additionally, the successful formation of the core-shell structure was verified through transmission electron microscopy (TEM), fluorescence microscopy, and Fourier transform infrared spectroscopy (FTIR). Additionally, both ZnO and THY exhibit strong antibacterial properties, and their synergistic effect significantly enhances the antibacterial activity of the composite nanofiber membranes against Staphylococcus aureus . The drug sustained release percentages within 24 h for PLA@T and PLA/Z@T were 15.91 % and 14.82 %, respectively. The addition of zinc oxide does not significantly affect the release efficiency of thymol. After continuous release for 288 h, these percentages increased to 73.35 % and 72.94 %, respectively. By assessing antioxidant activity through DPPH and ABTS assays, it was found that PLA/Z@T exhibited higher activity compared to the control group. Subsequently, the in vitro antibacterial performance was investigated, revealing an antibacterial rate higher than that of the control group, the antibacterial rates against Staphylococcus and Escherichia coli reached 99.75 % and 98.49 % respectively. In conclusion, the results demonstrate that PLA/Z@T nanofiber membranes possess excellent antibacterial efficiency, sustained antibacterial performance, and antioxidant properties, offering a novel strategy for antibacterial materials.