Drug-Free Coaxial Electrospinning via Pure Structural Engineering: Synergistic Enhancement of Mechanical Property, Bacterial Shielding, and Bioactivity.

Electrospun nanofibrous membranes, which structurally mimic the extracellular matrix, hold significant promise in wound repair applications. However, in the current gelatin (Gel)/polycaprolactone (PCL) system, the beneficial effects of Gel and PCL are usually discussed only from the material level, and how their spatial organization within fibers affects interfacial bioactivity, wet-state stability, and bacterial barrier performance remains insufficiently distinguished from the effects of added functional agents. In this study, Gel/PCL fibrous membranes were prepared via uniaxial blending (GPC, Gel/PCL composite) and coaxial core-shell electrospinning (GPS, Gel-shell/PCL-core), aiming to investigate how the fiber structure itself affects the performance of wound dressings. The GPS membrane features a PCL core for structural support and a Gel shell for biofunctionalization. This structure simultaneously enhanced surface hydrophilicity, liquid absorption capacity, and water vapor transmission while maintaining mechanical stability. Moreover, compared with the GPC membrane, it exhibited superior bacterial barrier performance, significantly promoted fibroblast adhesion and migration, and showed excellent hemocompatibility with a hemolysis rate below 2%. These results indicate that, even within the same Gel/PCL material system, spatial organization of the two components critically determines the balance among mechanical support, interfacial bioactivity, and barrier function, providing a rational structural-engineering strategy for drug-free multifunctional wound dressings.