Max Planck Institute for Polymer Research, 55128 Mainz, Germany.
Max Planck Institute for Polymer Research, 55128 Mainz, Germany.
J Control Release. 2016 Nov 28;242:119-125. doi: 10.1016/j.jconrel.2016.08.040. Epub 2016 Aug 31.
The controlled release of payloads from mesoporous silica nanocapsules (SiNCs) consisting of stimulus-responsive shells is of considerable interest in applications such as self-healing materials and drug delivery. However, the release of payloads from SiNCs before application of external triggers (i.e. non-selective release) remains a formidable challenge. In fact, the non-selective release of payloads from SiNCs occurs because of the mesoporous nature of the silica shell that cannot trap payloads in the core of SiNCs perfectly. We establish an efficient and straightforward strategy based on the encapsulation of a pro-active payload to hinder the non-selective release of small payloads from mesoporous capsules. A pro-active payload is defined as a compound that is converted to an active functional molecule in the environment where it is needed. In this sense, it is a generalization of a prodrug. Encapsulating a pro-active payload instead of a payload allowed hindering the non-selective release of the payload from SiNCs. A selective release of the payload could be achieved upon reduction of the encapsulated pro-active payload. Furthermore, the total amount of released substance is significantly enhanced by introducing responsive groups in the silica shell. These results show that the pro-active payload strategy combined with the use of stimulus-responsive materials can be successfully exploited to achieve selective release of cargo from mesoporous nanocapsules.
介孔硅纳米胶囊（SiNCs）中包含刺激响应外壳，其有效负载的控制释放对于自修复材料和药物输送等应用非常重要。然而，在应用外部触发（即非选择性释放）之前，从 SiNC 中释放有效负载仍然是一个巨大的挑战。事实上，由于二氧化硅壳的介孔性质，无法将有效负载完全捕获在 SiNC 的核中，导致 SiNC 中有效负载的非选择性释放。我们建立了一种基于前药有效负载包封的有效且简单的策略，以阻止小有效负载从介孔胶囊中进行非选择性释放。前药被定义为在需要的环境中转化为活性功能分子的化合物。从这个意义上说，它是前药的一种广义化。与包封有效负载相比，包封前药可以阻止有效负载从 SiNC 中进行非选择性释放。在还原封装的前药时，可以实现有效负载的选择性释放。此外，通过在二氧化硅壳中引入响应性基团，可以显著增强释放物质的总量。这些结果表明，前药策略与使用刺激响应材料相结合，可以成功地用于实现介孔纳米胶囊中货物的选择性释放。
