Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070, Würzburg, Germany.
Institute of Organic Chemistry and Center for Nanosystems Chemistry, University of Würzburg, Am Hubland, 97070, Würzburg, Germany.
Chemistry. 2019 Sep 25;25(54):12601-12610. doi: 10.1002/chem.201902619. Epub 2019 Sep 2.
Polymer micelles are an attractive means to solubilize water insoluble compounds such as drugs. Drug loading, formulations stability and control over drug release are crucial factors for drug-loaded polymer micelles. The interactions between the polymeric host and the guest molecules are considered critical to control these factors but typically barely understood. Here, we compare two isomeric polymer micelles, one of which enables ultra-high curcumin loading exceeding 50 wt.%, while the other allows a drug loading of only 25 wt.%. In the low capacity micelles, steady-state fluorescence revealed a very unusual feature of curcumin fluorescence, a high energy emission at 510 nm. Time-resolved fluorescence upconversion showed that the fluorescence life time of the corresponding species is too short in the high-capacity micelles, preventing an observable emission in steady-state. Therefore, contrary to common perception, stronger interactions between host and guest can be detrimental to the drug loading in polymer micelles.
聚合物胶束是一种有吸引力的方法，可以溶解水不溶性化合物，如药物。药物负载、制剂稳定性和控制药物释放是载药聚合物胶束的关键因素。聚合物主体与客体分子之间的相互作用被认为是控制这些因素的关键，但通常理解甚少。在这里，我们比较了两种同构聚合物胶束，其中一种能够实现超过 50wt.%的超高姜黄素负载，而另一种仅允许 25wt.%的药物负载。在低容量胶束中，稳态荧光显示出姜黄素荧光的一个非常不寻常的特征，即 510nm 处的高能发射。时间分辨荧光上转换表明，在高容量胶束中，相应物种的荧光寿命太短，无法在稳态下观察到发射。因此，与普遍看法相反，主体和客体之间更强的相互作用可能不利于聚合物胶束中的药物负载。
