Chen Guotao, Teng Zhaogang, Su Xiaodan, Liu Ying, Lu Guangming
J Biomed Nanotechnol. 2015 Apr;11(4):722-9. doi: 10.1166/jbn.2015.2072.
The degradation behavior of mesoporous silica nanoparticles (MSNs) influences their biological applications. The present study was a systematic investigation of the biological degradation behavior of mesoporous silica synthesized by the Stöber method. Different sized Stöber mesoporous silica nanoparticles were prepared and immersed in simulated body fluid, and degradation curves were obtained by measuring the dissolved silicon content of the fluid. Structural changes during degradation were observed by transmission electron microscope (TEM). The Stöber mesoporous silica nanoparticles tended to become hollow during the degradation process, and each particle was almost completely degradable from its interior to its exterior. Because of this unique degradation behavior, the morphology of the Stöber mesoporous silica nanoparticles can be retained even after over 85% of the silica degraded. Thus, during degradation, the dispersibility of the silica particles was superior to that of MSNs prepared in aqueous phases. Furthermore, the degradation behavior, intracellular distribution, and structural transformation of Stöber mesoporous silica nanoparticles in human embryo kidney 293T cells were investigated by measuring the silicon content in culture medium and analyzing TEM images. When these silica nanoparticles degraded in cells, their size and dispersibility remained unchanged, which would reduce the biological toxicity associated with the accumulation of silica aggregates in tissues. Overall, these results demonstrate that Stöber mesoporous silica nanoparticles can degrade in biological medium from inside to outside and maintain their good dispersibility, which suggests that these nanoparticles have great potential for applications as degradable biomedical materials such as drug carriers.
介孔二氧化硅纳米颗粒（MSNs）的降解行为会影响其生物学应用。本研究对通过施托伯法合成的介孔二氧化硅的生物学降解行为进行了系统研究。制备了不同尺寸的施托伯介孔二氧化硅纳米颗粒，并将其浸入模拟体液中，通过测量液体中溶解的硅含量获得降解曲线。通过透射电子显微镜（TEM）观察降解过程中的结构变化。施托伯介孔二氧化硅纳米颗粒在降解过程中倾向于变成中空的，并且每个颗粒几乎可以从内部到外部完全降解。由于这种独特的降解行为，即使超过85%的二氧化硅降解后，施托伯介孔二氧化硅纳米颗粒的形态仍可保留。因此，在降解过程中，二氧化硅颗粒的分散性优于水相制备的MSNs。此外，通过测量培养基中的硅含量并分析TEM图像，研究了施托伯介孔二氧化硅纳米颗粒在人胚肾293T细胞中的降解行为、细胞内分布和结构转变。当这些二氧化硅纳米颗粒在细胞中降解时，它们的大小和分散性保持不变，这将降低与二氧化硅聚集体在组织中积累相关的生物毒性。总体而言，这些结果表明，施托伯介孔二氧化硅纳米颗粒可以在生物介质中从内到外降解并保持其良好的分散性，这表明这些纳米颗粒作为可降解生物医学材料如药物载体具有巨大的应用潜力。
