Chemical characteristics and hemostatic performances of ordered mesoporous calcium-doped silica xerogels

A well-ordered mesoporous silicon dioxide calcium-doped xerogel (m-SXC) was synthesized by a sol-gel process. The in vitro bioactivity of the m-SXC was investigated by analyzing the apatite-forming ability in simulated body fluid (SBF) and MC3T3-E1 cell culture with materials, and the hemostatic activity of the m-SXC was determined by measuring the activated partial thromboplastin time (APTT) and prothrombin time (PT) in vitro. The results suggested that the m-SXC exhibited excellent in vitro bioactivity, with surface apatite formation for the m-SXC containing 10 w% Ca (m-SXC10) exceeding that containing 5 w% Ca (n-SXC5) and 0% Ca (m-SXC0) at 7 days, and the cell response test (MTT assay) and cell morphology observation demonstrated that these materials were biocompatible with no obvious negative effects on cellular viability. Moreover, the m-SXC with a high surface area (m-SXC0: 489.9 m2 g-1, m-SXC5: 466.5 m2 g-1, m-SXC10: 438.1 m2 g-1) possessed good hemostatic property because it could absorb a large amount of water from the blood, which could concentrate the components of blood and reduce the clotting time. Furthermore, the addition of calcium in the m-SXC had significant effects on the clotting time, in which the APTT (m-SXC0: 8 s, m-SXC5: 7 s, m-SXC10: 6 s, respectively) and PT (m-SXC0: 16 s, m-SXC5: 11 s, m-SXC10: 10 s, respectively) were shortened with the increase of Ca amounts in the m-SXC, indicating that incorporation of Ca in the m-SXC could improve its hemostatic activity.