Auxiliary electrode tunes wet-electrospun bundle stiffness to modulate cell phenotype

The stiffness of tissue-engineered scaffolds significantly influences cell behaviour and phenotype. However, current approaches to tuning stiffness often introduce unintended variations and compromise topographical consistency. In this study, an innovative wet-electrospinning set-up, incorporating a positively charged auxiliary electrode was developed to fabricate bundles with adjustable stiffness. COMSOL-based electromechanical computing revealed that the auxiliary electrode provided electrostatic force, which reduced stress concentration during continuous polycaprolactone (PCL) bundle collection at speeds up to 120 m min⁻¹. Tensile testing showed that increasing collection speed significantly enhanced bundle stiffness, with Young’s modulus rising from 40 to 107 MPa. X-ray diffraction analysis indicated that this strengthen effect was associated with crystal disintegration and grain refinement within PCL fibre. These changes were reflected in scaffold stiffness, thereby, further influenced cell behaviour, as bundles with higher stiffness promoted a transition from non-polarised to spindle-like cell morphology. This electrostatic-assisted collection wet-electrospun setup enables the fabrication of scaffolds with tuneable mechanical properties while preserving topographical consistency, offering a robust strategy for mechanobiology research and tissue engineering.