Ductility and Porosity of Silk Fibroin Films by Blending with Glycerol/Polyethylene Glycol and Adjusting Drying Temperature

Ductility and porosity of bio-functional films (BFFs) are the critical properties for mechanical compliance and intercellular communication in tissue engineering. However, it remains significant challenge to integrate these two key properties into BFFs. Herein, silk fibroin (SF) films with tunable ductility and porosity were prepared by adjusting the protein self-assembly process through combinations with glycerol (Gly) and polyethylene glycol 400 (PEG400) and regulating the film-casting temperature (FCT). Typically, among various conditions screened, the BFFs with a mass ratio of SF/PEG400/Gly of 10:5:3 (SPG1053) prepared at 4°C exhibited remarkable ductility with a tensile strength of 2.7 ± 0.2 MPa and elongation at break of 164.24 ± 24.20%, superior to films prepared from SF alone, SF/Gly or SF/PEG400, demonstrating a synergistic plasticizing effect. Furthermore, the SPG1053 films prepared at 4°C had a permeation efficiency of 56.32 ± 0.85% for fluorescently labeled dextran (dextran-TMR, MW:10 KDa) aft...