Hydrogels: Coordination driven gelation
Hydrogels: Coordination driven gelation
复制标题
DOI：
10.1038/nchem.2339
复制
发表时间：
2015-09
期刊：
影响因子：
21.8
通讯作者：
T. B. Faust
中科院分区：
文献类型：
--
作者：
T. B. Faust
然而，在这种情况下，由于所使用的甲酰基吡啶已经通过大量的聚乙二醇链（Mn= 1000 g mol-1）预官能化，在加入金属离子时络合成笼同时强制聚合物聚集，从而驱动凝胶化。通过在微流化床反应器内控制前体溶液的混合，Nitschke和同事还能够制造出笼状交联水凝胶的规则尺寸的微粒。在水凝胶内，笼保留了它们选择性地容纳具有互补空间和电子性质的客体分子的能力。由于亚胺键的形成是可逆的，笼的分解可以通过引入竞争性胺或醛来触发，这释放了有效载荷并最终导致整个水凝胶的溶解。这些性质可以使这些材料实际上有用，也许作为药物递送载体。例如，类似的超分子笼可以在生物相容性水凝胶中选择性地容纳治疗有效负载。外部刺激的应用，或者实际上局部环境（例如pH）的变化，然后可以触发有效载荷释放。TF
However in this instance, since the formylpyridines used are already prefunctionalized by substantial polyethylene glycol chains (Mn= 1000 g mol–1), the complexation into a cage upon addition of metal ions simultaneously enforces polymer aggregation, and thus drives gelation. By controlled mixing of precursor solutions within a microfiuidic reactor, Nitschke and colleagues are also able to fabricate regularly sized microparticles of their cage-crosslinked hydrogels. Within the hydrogel, the cages retain their ability to selectively host guestmolecules with complementary steric and electronic properties. Since the imine bond formation is reversible, disassembly of the cage can be triggered by the introduction of competitive amines or aldehydes, which releases the payload and ultimately causes dissolution of the entire hydrogel. These properties may render these materials practically useful, perhaps as drug delivery vehicles. For example, a similar supramolecular cage could selectively host a therapeutic payload within a biocompatible hydrogel. The application of an external stimulus, or indeed a change in local environment (such as pH) could then trigger payload release. TF