Pacific Northwest National Laboratory, Richland, WA 99352, USA.
Anal Biochem. 2012 Feb 15;421(2):477-81. doi: 10.1016/j.ab.2011.09.024. Epub 2011 Oct 2.
We report here that under different physiological conditions, biomolecular drugs can be stockpiled in a nanoporous support and afterward can be instantly released when needed for acute responses, and the biomolecular drug molecules can also be gradually released from the nanoporous support over a long time for a complete recovery. Organophosphorus acid anhydrolase (OPAA) was spontaneously and largely entrapped in functionalized mesoporous silica (FMS) due to the dominant electrostatic interaction. The OPAA-FMS composite exhibited a burst release in a pH 9.0 NaHCO₃-Na₂CO₃ buffer system and a gradual release in pH 7.4 simulated body fluid. The binding of OPAA to NH₂-FMS can result in less tyrosinyl and tryptophanyl exposure OPAA molecules to aqueous environment. The bound OPAA in FMS displayed lower activity than the free OPAA in solution prior to the enzyme entrapment. However, the released enzyme maintained the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. The in vitro results in the rabbit serum demonstrate that both OPAA-FMS and the released OPAA may be used as a medical countermeasure against the organophosphorus nerve agents.
我们在这里报告，在不同的生理条件下，生物分子药物可以被储存在纳米多孔载体中，并且在需要急性反应时可以立即释放，并且生物分子药物也可以在很长一段时间内从纳米多孔载体中逐渐释放以实现完全恢复。由于主静电相互作用，有机磷酸酐酶（OPAA）自发且大量地被包埋在功能化介孔硅（FMS）中。OPAA-FMS 复合材料在 pH9.0 的 NaHCO₃-Na₂CO₃缓冲系统中表现出爆发式释放，在 pH7.4 的模拟体液中表现出逐渐释放。OPAA 与 NH₂-FMS 的结合可以使更多的酪氨酸和色氨酸暴露在水溶液中。与溶液中的游离 OPAA 相比，结合在 FMS 中的 OPAA 显示出较低的活性。然而，释放的酶保持了天然构象结构和与酶包埋之前相同的高酶活性。在兔血清中的体外结果表明，OPAA-FMS 和释放的 OPAA 都可作为针对有机磷神经毒剂的医疗对策。
