Degradable, antibacterial silver exchanged mesoporous silica spheres for hemorrhage control

Effective hemorrhage control becomes increasingly significant in today's military and civilian trauma, and current available local hemostatic agents have been reported to have various drawbacks and side effects. Herein in this study, a silver exchanged calcium doped ordered mesoporous silica sphere (AgCaMSS) with good degradability and antibacterial properties was developed for hemorrhage control. The well-ordered and symmetry hexagonal AgCaMSS with pore size of 3.2 nm, BET surface area of 919 m(2)/g and pore volume of 0.74 m(3)/g was prepared by one-step based catalyzed self-assembly and subsequent ion-exchange procedures. The degradation behaviors in Tris-HCl solution indicated that the addition of calcium and silver facilitated the dissolution and the weight loss of the prepared AgCaMSS could attain more than 40% after 42 days. The results obtained demonstrated that the optimal AgCaMSS formulation could significantly promote the blood clotting, activate the intrinsic pathway of coagulation cascade, induce platelet adherence. Consequently, effective hemostasis with low exothermic effects was achieved and the mortalities in femoral artery and liver injury models were reduced. The antibacterial experiment using broth culture method revealed that the prepared AgCaMSS had better antibacterial activities against Escherichia coli and Staphylococcus aureus. Based on these results, it can be concluded that the AgCaMSS developed here would be a promising material platform for designing hemostats in more extensive clinical application. (C) 2009 Elsevier Ltd. All rights reserved.