Silk composite interfacial layer eliminates rebleeding with chitosan-based hemostats

Chitosan foams are among the approved hemostats for pre-hospital hemorrhagic control but suffer from drawbacks related to mucoadhesiveness and rebleeding. Herein, we have developed a designer bilayered hemostatic foam consisting of a bioactive layer composed of silica particles (≈300 nm) and silk fibroin to serve as the tissue interfacing component on a chitosan foam. The foam composition was optimized based on the in vitro clotting behavior and cytocompatibility of individual components. In vivo analysis in a rat model demonstrated that the developed hemostat could achieve rapid clotting (31 ± 4 s), similar to a chitosan-based hemostat, but the former had significantly lower blood loss. Notably, removal of the bilayered hemostat prevented rebleeding, unlike the chitosan foam, which was associated with markedly higher incidences of rebleeding (50 %) and left behind material residue. Thus, the designer bilayered foam presented here is a potent inducer of blood clotting whilst affording easy removal with minimal rebleeding.