The Potential of Tantalum-Doped Mesoporous Bioactive Glasses for Hemostasis

Synthesis and characterization of the first mesoporous bioactive glasses (MBGs) containing tantalum (Ta) are reported, alongside their potential as hemostats. A series of silica MBGs with the molar composition of (80-x)% Si, 15% Ca, 5% P and x% Ta, with x = 0 to 10, were synthesized by the sol-gel method. Increasing Ta content from 1 to 10 mol% caused a decrease in the surface area and pore volume of ~20% and ~35%, respectively, due to the increase in non-bridging oxygens and mismatch of thermal expansion coefficient which creates discontinuities in the ordered channel structure. However, the effect is not significant on the amount of ions released from the samples into deionized water, for short durations (<60 min). In a mouse tail cut model, a significant decrease (≥ 50%) in average bleeding time was found for Ta-MBGs compared to controls (commercial hemostat Arista® and a Ta-free MBG). There was no significance in hemolytic activity between plain blood and when MBG is present and cytotoxicity results show that increasing Ta content from 0 to 10% reduced MBG toxicity by more than 15%; this effect was visually confirmed by live/dead cell assays. Further studies are proposed to determine the mechanism of Ta involvement with the hemostatic process.