Abstract:
A tough, porous silk fibroin (SF)/polyethylene glycol (PEG) cryogel was prepared through a simple freeze-thawing procedure by using PEG as cross-linking agent. Fourier-transform infrared (FT-IR) spectra, scanning electron microscope (SEM) and universal-testing machine were used to investigate the conformational change, micromorphology, mechanical properties, and swelling behaviors of cryogels. Results demonstrated that the incorporation of PEG faclitated the formation of crystal structures of SF chains, and the microstructure and mechanical properties can be tailored by freezing temperature, mass ratio of PEG to SF (
mPEG/
mSF), and SF mass fraction. When freezing temperature was −20 °C,
wSF = 0.16, and
mPEG/
mSF = 0.50, the compressive modulus of the SF/PEG cyrogels was up to 0.44 MPa and can tolerant large compressive strain (90%) without permanent deformation and fracture. The cryogel also demonstrated excellent elasticity recovery during cyclic compression test, and the Young’s modulus and toughness of cryogels could reach up to 4.15 MPa and 680.81 kJ/m
3, respectively. The cryogels with homogeneously distributed inter-connected porous structure would promote their potential applications in tissue engineering field.