Mimicking nature: Shish-kebab topology in nanofibers enhances antibacterial and mechanical properties

Shish-kebab topology is of growing interest because of its excellent extracellular matrix biomimetic performance in the field of tissue engineering. To explore the effect of the nanostructure surface of fibers on the properties of nanomaterials, a composite membrane with shish-kebab topology was prepared by electrospinning and self-induced crystallization. The surface morphology, crystallinity, hydrophilicity, mechanical properties, and antibacterial properties of the composite membranes were characterized. The effects of different concentrations of polycaprolactone (PCL) on the properties of the composite nanomaterials were explored. The results showed that films prepared with 14% PCL had an obvious shish-kebab nanostructure after self-induced crystallization, with an average kebab size of 110.7 nm and a periodicity spacing of 278.14 nm, while the periodic distances of samples with 12% and 17% PCL were closer to the gap region size of collagen fibers. The self-induced crystallization increased the crystallinity of the original membranes, and also the hydrophobicity. At the same time, the mechanical properties of the crystallized membranes were improved, with the tensile strength being two to four times that of the original membranes. Antibacterial experiments revealed that the same antibacterial effect can be achieved by using less than half of the antimicrobial dose, significantly reducing the amount of antibacterial agents used. The shish-kebab structures achieved in this study closely mimic the collagen fibrils in the extracellular matrix, and the preparation method has the potential to mitigate the development of bacterial resistance to a certain degree, offering a new research direction for the development of highly effective antibacterial materials.