Process-Driven Modulation of Structure and Cytocompatibility in Electrospun Silk Fibroin Membranes through Controlled...

The degumming process technique critically determines the structural and biological performance of silk fibroin-based biomaterials. In this study, silk fibroin obtained from Bombyx mori cocoons was subjected to a controlled experimental design that combined sodium carbonate (Na₂CO₃), sodium lauryl ether sulfate (SLES), and reaction time to modulate the efficiency of sericin removal. Degumming effectiveness was quantified by mass loss and chemical analysis (FTIR-ATR, solid-state ¹³C NMR), while structural modifications were evaluated by X-ray diffraction. Alkaline-based degumming treatments (C4-C9) achieved sericin removal efficiencies above 90%, promoted β-sheet exposure, and resulted in higher crystallinity compared to surfactant-only treatments. Regenerated silk fibroin was processed by solution electrospinning under controlled conditions. The electrospun porous membranes exhibited predominantly random-coil conformations, with crystallinity values ranging from 24-38%. Cytocompatibility assessment using human dermal fibroblasts demonstrated a concentration-dependent response. The morphology of the electrospun fibers, including surface roughness and wettability (SEM, microindentation, and contact angle measurements), led to adequate adhesion of normal fibroblasts. Additionally, the mechanical properties, including hardness, Young's modulus, and elongation, provide suitable elastic properties for fibroblast proliferation. Membranes derived from alkaline-treated fibroin showed cell viability above 80%, while surfactant-only treatments exhibited reduced metabolic activity at full extract concentration. No intrinsic antibacterial activity was observed against Staphylococcus aureus or Pseudomonas aeruginosa. These findings demonstrate that the degumming strategy and electrospinning conditions are key upstream parameters regulating structure-property-cytocompatibility relationships in electrospun silk fibroin membranes. Optimal alkaline degumming and electrospinning conditions enhance biological safety and reproducibility for tissue engineering applications.