Sericin/silk fibroin composite aerogel for hemostatic application

Uncontrolled massive bleeding is a major cause of death, and effective hemostasis is important for reducing suffering and improving survival rates. Silk sericin (SS) exhibits excellent water absorption properties, and incorporating silk fibroin (SF) with SS can enhance the formability of SS materials. SS peptide chains include numerous polar functional groups that coordinate with Ca2+ to induce physiological hemostasis. We developed Ca2+-loaded SS/SF aerogels by enzyme crosslinking/freeze-drying, and investigated their water absorption, flexibility, cytotoxicity, and hemostatic performance. A higher SS content of the SS/SF aerogels was associated with greater Ca2+ loading, but aerogels with a high SS content (>70 %) were also fragile. The water absorption rate and initial modulus of the aerogels decreased with increasing Ca2+ loading. Furthermore, the hemostatic performance of SS was significantly better than that of SF, and gradually improved with increasing Ca2+ content. Ca2+-loaded SS/SF aerogels absorbed water rapidly and transformed into soft hydrogels to seal bleeding ear wounds in rabbits, in an SS dose-dependent manner. Ca2+-loaded SS/SF aerogels showed no obvious cytotoxicity. These results indicated that Ca2+-loaded SS/SF aerogels with an SS:SF ratio of 8:2 provided a satisfactory hemostatic material, with a significantly better hemostatic performance than commercial gelatin sponges or medical gauze, attributed to a combination of physical and physiological pathways to achieve rapid hemostasis.