Zinc Borate (ZnB)-Incorporated Electrospun Polycaprolactone (PCL) Fibers: Multifunctional Antimicrobial Materials

In this study, due to its multifunctional nature, zinc borate (ZnB) was incorporated into electrospun polycaprolactone (PCL) fibers in various concentrations (1.5%, 3.5%, 5%, wt%). The homogenous fiber morphology, the varying fiber diameter distribution, and the presence of ZnB in PCL fibers were shown by SEM/EDS and FTIR analysis. TGA analysis revealed that the addition of ZnB into the matrix enhanced the thermal stability of polymer as evidenced by an increase in the temperature at 10% mass loss (T10) from 365 degrees C to 390 degrees C. The fire-retardant performance of the PCL fibers, as assessed by the calculated limiting oxygen index (LOI), exhibited an improvement from 17.65 to 18.83 upon the incorporation of 5 wt% ZnB. Mechanical test results revealed that the tensile strength increased from 2.36 MPa to 3.46 MPa, while the Young's modulus decreased from 25.06 MPa to 17.99 MPa for PCL-Control and 5 ZnB-PCL fibers, respectively. ZnB-PCL fibers had potent antibacterial effects against both Gram-positive, Gram-negative, antibiotic-resistant bacteria, and fungal strains. Furthermore, cytocompatibility analysis using mouse fibroblast cells (L929) indicated that ZnB-PCL fibers supported cell adhesion, spreading and proliferation, even in 5 ZnB-PCL fibers containing the highest amount of ZnB. The development of a material that simultaneously exhibits broad-spectrum antimicrobial activity while supporting cell viability and proliferation is highly significant. In this context, the findings of this study suggest that ZnB-PCL fibers are promising candidates for wound dressings and tissue engineering scaffolds with improved mechanical and biological properties, as well as industrial fields requiring antimicrobial properties.