Graphene-Montmorillonite Composite Sponge for Safe and Effective Hemostasis.

Montmorillonite (MMT) is considered to be the most effective hemostat among natural phyllosilicates. However, there is a barrier against using MMT for the commercial hemostatics because the invaded MMT powders might cause thrombosis in vessel. Until now, it is still a challenge to manage the release of MMT and eliminate its side effect. Herein, we present a graphene-MMT composite sponge (GMCS), synthesized under a hydrothermal reaction, fixing MMT powders into the cross-linked graphene sheets. We demonstrate that only a few embedded MMT can evoke remarkable platelet stimulation at the sponge interface, while maintaining fast plasma absorbency of the innate sponge. In the synergy of the above hemostatic mechanisms, the GMCS can rapidly stop bleeding in approximately 85 s in rabbit artery injury test. More importantly, computed tomography angiography certifies that the GMCS does not cause thrombus or blood clot in vessels. Cytotoxicity assay further highlights its biocompatibility. In-depth analysis proposes that two-dimensional graphene overmatches one-dimensional linear polymers in the composite construction, and dimension transformation of blood distribution plays a crucial role for reinforcing the hemostatic performance. This GMCS hemostat not only opens a new perspective for graphene composite, but also makes a new chance of using clays for trauma therapy.