Development of Chitosan and Silk Fibroin Nanofibers Incorporated With ZnO and TiO2 Nanoparticles for Wound Dressing Applications

Wound infections remain a significant challenge, often complicating the healing process. Consequently, there is a growing need for innovative alternatives to conventional treatment strategies. In recent years, electrospun nanofibers (NFs) made from natural or synthetic polymers have gained popularity as wound dressing materials due to their structural similarity to the extracellular matrix and ability to incorporate bioactive agents. This study aimed to develop multifunctional wound dressings by incorporating zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO₂ NPs) separately into polymeric NFs made of chitosan (CS), silk fibroin (SF), and polyethylene oxide (PEO). The NFs were fabricated using the electrospinning technique, and three formulations were prepared: plain CS/SF NFs, CS/SF/ZnO NFs, and CS/SF/TiO₂ NFs. These were systematically characterized and compared in terms of their physicochemical, mechanical, and biological properties to evaluate their potential for wound dressing applications. The chemical composition, thermal stability, morphology, and mechanical properties of the prepared NFs were evaluated using FTIR, TGA, SEM, and tensile strength tests, respectively. FTIR analysis confirmed the successful integration of the polymers and nanoparticles. The addition of ZnO and TiO₂ NPs improved the thermal stability and mechanical strength of the NFs. SEM images revealed that all NFs exhibited long, continuous, and bead-free morphologies. Additionally, the swelling ratio, degradation behavior, and water vapor transmission rate (WVTR) were assessed. Swelling studies indicated a high water absorption capacity with pH-dependent behavior, especially under acidic conditions. Biodegradation tests showed a slower degradation rate in the NFs containing NPs. The WVTR results confirmed that all NF formulations are suitable for maintaining an optimal moisture environment for wound healing. Cell viability assays demonstrated good biocompatibility, while antimicrobial studies revealed strong bactericidal activity in CS/SF/ZnO NFs. In contrast, CS/SF/TiO₂ NFs exhibited limited antimicrobial activity in the absence of UV light. Overall, the findings suggest that CS/SF-based NFs, particularly those containing ZnO, are promising candidates for advanced wound dressing applications due to their enhanced structural integrity and biological functionality.