Abstract
Electrospinning (e-spinning) has been widely applied to fabricate flat films accumulated by microfibers for tissue engineering. In order to acquire an uneven surface morphology, two methods have been applied traditionally. The first uses a designed receiving substrate, which is stable, but suppresses the flexibility. The second uses dual solvents to achieve bimodal distribution of the fiber diameter. However, the bimodal fiber diameter causes inhomogeneity. To solve these challenges, cryogenic electrospinning, using a flat substrate and a single solvent, was performed in this study to obtain uneven films. By applying a low temperature to the flat receiving substrate, uneven e-spun films with wall-like structures were achieved through the self-assembly of uniform filaments. In addition, the wall-like structures enhanced the mechanical properties of the e-spun films. Moreover, the cryogenic e-spinning produced micropores on the fiber surface, which have the potential to promote esophageal epithelial cell adhesion, proliferation and differentiation.