Impact of Surface Metal Composition on the Blood Coagulation Activity of Diatoms Biosilica

The interface properties of the material will significantly affect essential steps in the coagulation reaction, such as platelet activation, fibrin assembly, and erythrocyte adsorption. Diatoms biosilica (DBs) is an emerging inorganic porous hemostatic material that has achieved fast hemostasis because of its strong water absorption-concentration effect. Changing the interfacial properties of diatoms can expand the application scenarios to meet different hemostatic needs. Herein, three metal mineralized DBs including Ca mineralized DBs (Ca-DBs), Zn mineralized DBs (Zn-DBs) and Cu mineralized DBs (Cu-DBs) were developed through a hydrothermal method. It was found that the surface metal mineralization composition had a significant effect on the bioactivity of DBs, which was reflected in the ultrafast coagulation of Ca-DBs, and the different levels of anticoagulant and bacteriostatic properties of Zn-DBs and Cu-DBs. Metal-mineralized DBs retain most of their original microstructure and carry a decreased charge on the surface. In vitro results showed that metal mineralization significantly reduced the hemolysis rate of DBs, but Cu decreased the cytocompatibility. The three metal-mineralized materials affect endogenous and exogenous coagulation pathways as well as thrombin activity to different degrees. Among them, Zn-DBs promoted intrinsic coagulation at low concentrations and competitively inhibited thrombin activity at high concentrations. The animal studies confirmed the above result, with Ca-DBs having the most significant coagulation effect in the in vivo hemostatic assessment (coagulation time of only 37 s and blood loss of only 0.17 g). This study not only elucidated impact of surface metal composition on the blood coagulation activity of DB, but also provided a strategy to regulate the coagulation behavior of inorganic porous materials.