Thymol-loaded polylactic acid electrospun fibrous membranes with synergistic biocidal and anti-bacterial adhesion properties via morphology control

Antibiotic resistance is a growing challenge in modern medicine, highlighting the urgent need for alternative antimicrobial strategies. The combination of synergistic sterilization and inhibition of bacterial adhesion presents a promising approach for achieving a long-lasting antibacterial effect. Herein, we report the fabrication of thymol-loaded polylactic acid (Thy-PLA) porous fibrous membranes that exhibit both bacteria-killing and bacteria-repellent functions, accomplished through control of microstructure and morphology during the electrospinning process. Notably, we employed the breath figure method, a humidity-induced morphology control technique, which significantly increased the surface roughness of the Thy-PLA fibers and resulted in a nano-porous structure for bacterial repulsion. Additionally, this method facilitated the enhanced release of thymol, thereby enabling efficient sterilization. By simply modifying the morphology, we achieved bacterial reduction rates of up to 99.92 % and 99.87 % for Escherichia coli and Staphylococcus aureus, respectively, and robust mechanical properties (ultimate tensile stress of 20 MPa and elongation at break of 822.7 %). Furthermore, the fibrous membranes exhibited an impressive oil/water absorption capacity (∼36.7 g/g in 90 s) thanks to the interior and surface porosity. The porous fibrous membranes with synergistic antimicrobial efficiency and tunable mechanical properties demonstrate great potential for diverse applications, particularly in wound dressing and oil/water filtration.