Preparation of Chitosan/ZnO/Zinc Alginate Composite Fibers with Synergistic Antibacterial Properties

Inhibiting bacterial growth on wound surfaces is crucial for accelerating wound healing. Although antibiotics are commonly used to address the antibacterial needs of inflammatory wounds, their use can lead to bacterial resistance. To avoid the prolonged use of antibiotics while meeting the antibacterial requirements during the wound healing process, the combination of natural antibacterial materials with inorganic antibacterial agents to create efficient antimicrobial medical composites has shown promising potential. In this work, we first prepared a spinning solution by combining zinc oxide (ZnO) with chitosan (CS). Using a wet spinning process, CS/ZnO fibers were fabricated. Subsequently, a layer of zinc alginate (Alg-Zn) was coated on the surface of the CS/ZnO fibers through an in situ impregnation technique, resulting in the formation of composite fibers with high-efficiency and sustained antibacterial properties. Due to the inherent cationic antibacterial activity of CS and the zinc ion release from both Alg-Zn and ZnO, the composite fibers exhibited excellent antibacterial performance. The maximum inhibition zones against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were 6.7, 4.3, and 2.5 mm, respectively. Benefiting from the Schiff base reaction between CS and Alg-Zn, the composite fibers maintained good mechanical properties, with a tensile strength of 170 ± 2 MPa. Additionally, the composite fibers demonstrated favorable biocompatibility, moisture absorption, and breathability. This work provides valuable data for the design and preparation of antibacterial functional fibers and offers an approach for the development of high-efficiency antibacterial medical composites.