Abstract Incorporation of degradable groups such as thioether bonds can make nanoparticles susceptible to be degraded by biological redox stimulus. Few studies have paid attention to effects of different surface properties of carriers on degradation behaviors between traditional mesoporous silica carriers and hybrid organosilica carriers, caused by inserted thioether groups. In this work, colloidal mesoporous silica (CMS) and hybrid colloidal mesoporous silica (HCMS) with different contents of doped thioether bonds are constructed to compare their physicochemical properties and degradability. With the increased amounts of doped thioether bonds, specific surface areas and Zeta potentials of HCMS nanoparticles decrease. Additionally, dynamic contact angle and the oil-water distribution coefficient are combined to characterize the hydrophobicity of CMS and HCMS nanoparticles. Therefore, after incorporating thioether bonds into the structure of carriers, the degradation behavior of HCMS nanoparticles in the medium were the result of weighing the advantages of degradable thioether bonds and disadvantages of decreased specific surface area and enhanced hydrophobicity of carriers. Experimental results displayed that, in the high concentration of reductive environment, HCMS carriers with doping proper proportion of thioether groups showed the fast degradation rate due to the cleaved thioether bonds as the dominant factor. The present work breaks the common views that all thioether bonds-bridged organosilica could become excellent biodegradable carriers, providing an objective perspective to evaluate the degradability of hybrid organosilica carriers.

中文翻译：

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硫醚桥连杂化介孔有机二氧化硅纳米粒子氧化还原引发降解的评价

摘要 硫醚键等可降解基团的引入可以使纳米颗粒易于被生物氧化还原刺激降解。很少有研究关注载体的不同表面性质对传统介孔二氧化硅载体和杂化有机二氧化硅载体之间由插入的硫醚基团引起的降解行为的影响。在这项工作中，构建了具有不同掺杂硫醚键含量的胶体介孔二氧化硅（CMS）和混合胶体介孔二氧化硅（HCMS），以比较它们的理化性质和降解性。随着掺杂硫醚键数量的增加，HCMS 纳米颗粒的比表面积和 Zeta 电位降低。此外，动态接触角和油水分配系数相结合来表征 CMS 和 HCMS 纳米粒子的疏水性。因此，将硫醚键引入载体结构后，HCMS纳米粒子在介质中的降解行为是在可降解硫醚键的优点与载体比表面积降低和疏水性增强的缺点之间权衡的结果。实验结果表明，在高浓度的还原环境中，硫醚基团以断裂的硫醚键为主导因素，掺杂适当比例的硫醚基团的HCMS载体表现出较快的降解速率。目前的工作打破了所有硫醚键桥接的有机二氧化硅都可以成为优秀的可生物降解载体的普遍看法，