Interactions between two-dimensional nanoclay and blood cells in hemostasis.

Uncontrolled bleeding following trauma is associated with a high risk of death. The two-dimensional (2D) nanoclay kaolinite as an effective hemostatic has been developed for early intervention to prevent blood loss. However, the interfacial interactions between kaolinite and blood cells in hemostasis, and the effects of the stacking structure or particle size of kaolinite on bleeding control are unclear. Here, the interactions between kaolinite and blood cells were analyzed qualitatively and quantitatively by using scanning electron microscopy, confocal laser-scanning microscopy, and flow cytometry. The results showed that kaolinite not only bonds with platelets but also induces platelets aggregation, and does not disturb red blood cells, which facilitates the formation of blood clotting in hemostasis. Further, kaolinite nanoclay with smaller nanosheets and looser aggregation showed higher hemostatic activity, which was attributed to the higher water absorption capacity, and the ability to activate the intrinsic coagulation pathway and platelets activation and aggregation. Accordingly, controlling the particle size or thickness and aggregate status of kaolinite or 2D nanoclay nanosheets could be an alternative strategy for enhancing the hemostatic activity of 2D nanoclay-based materials.