Hierarchical Micro-Nano Porous Structure of Diatom Biosilica Induces Selective Absorption and Protease Inhibition for Bleeding Control.

Diatom biosilica (DB), derived from the shells of diatoms, is a natural micronano inorganic porous material with excellent properties for protein adsorption that show strong, powerful procoagulant activity. However, the precise mechanism by which DB affects physiological processes in blood has not been elucidated. Herein, we explore DB-initiated blood coagulation at the molecular level, revealing that the selective absorption and protease inhibition behavior induced by the size sieving effect of DB can drive the blood system into a hypercoagulable state. Unlike physiological coagulation, DB-induced blood coagulation displays an unusual negative feedback regulation pattern, with exceptionally selective absorption of antithrombin III and alpha-2-antiplasmin by at least 10-fold and inhibition of their activity by more than 70%, thus giving it super procoagulant activity. The animal studies confirmed that DB could control bleeding in heparinized rats and rabbits within 5 min, demonstrating its potential application in hemorrhagic diseases. Our findings provide a mechanistic understanding of how the hierarchical porous structure of DB functionally contributes to blood coagulation, providing insight into the design of improved hemostatic agents for bleeding control.