Preparation and Properties of Semi-Interpenetrating Silk Fibroin Protein Hydrogels with Integrated Strength and Toughness

Two series of semi-interpenetrating network hydrogels (P(AAN-co-AAM)-SF and P(AA-co-AAM)-SF) were constructed through one-step blending of silk fibroin with sodium acrylate or acrylic acid followed by ultraviolet (UV)-initiated free-radical copolymerization. The resulting silk fibroin composite hydrogels exhibited excellent mechanical properties due to the semi-interpenetrating network hydrogel formed by sodium polyacrylate and silk fibroin. Specifically, the P(AAN-co-AAM)-SF hydrogel showed a high fracture stress of 1.01 MPa, an elongation at break of 2000%, a high compressive strength of 17 MPa, and could be compressed up to 200 cycles without damage. Compared with other silk fibroin hydrogels, this work was in a leading position in terms of mechanical properties and antidrying ability. In addition, silk fibroin-based hydrogels showed no cytotoxicity, certain UV-shielding ability, and were specifically poured into pig tracheal sections, indicating the potential for future use as biological materials.