Block copolymer self-assembly in solution

嵌段共聚物囊泡（BCVs）是由两亲性双嵌段共聚物在溶液中制备的空心球体。它们的尺寸范围从约100到约1000纳米，壁厚约20纳米。在早期的工作中，我们已经表明，通过控制制备条件，可以很容易地制备嵌段共聚物囊泡。它们是包括球形胶束和棒状物的形态连续体的一部分。与脂质体一样，bcv在药理学（药物输送）、化妆品和催化等领域有许多潜在的应用前景，但比脂质体稳定得多。我们最近已经表明，许多囊泡参数，如大小和壁厚，可以由外部制备条件和聚合物组成来控制。我们还证明了在一步中制备具有不同内部和外部界面的囊泡是可能的。此外，我们已经证明，有可能根据需要软化壁，允许活性填充成分，如阿霉素（一种癌症杀手），通过硬化壁来锁定成分，然后根据需要“重新打开”以释放内容物。我们还表明，通过交换内部和外部界面来反转囊泡是可能的。我们现在建议在囊泡中探索一种“呼吸”机制，它允许它们在大约1分钟内以大约10倍的倍数反复增加或减少体积。这将使成分的吸收和释放非常迅速。我们还学会了如何将纳米颗粒（如树突状分子）整合到囊泡壁中，现在我们建议系统地研究将许多不同物种（包括催化剂）整合到囊泡壁中。此外，我们建议研究特定几何形状的物种（如球体）与嵌段共聚物聚集体的结合，并研究强相互作用对最终聚集体形态形成的影响。其他几项次要研究正在考虑中，包括探索通过囊泡壁的扩散和在囊泡腔内捕获大分子。

Block copolymer vesicles (BCVs) are hollow spheres which can be prepared in solution from amphiphilic diblock copolymers. They range in size from ca. 100 to ca. 1000 nm, with a wall thickness of ca. 20 nm. In early work, we have shown that block copolymer vesicles can be prepared very easily by controlling the preparation conditions. They are part of a morphological continuum which includes spherical micelles and rods. Like liposomes, BCVs are promissing in many potential applications in fields such as pharmacology (in drug delivery), cosmetics and catalysis, but are much more stable than liposomes. We have shown recently that many vesicle parameters, such as size and wall thickness, can be controlled by external preparative conditions and polymer composition. We have also shown that it is possible to prepare, in one step, vesicles with different interior and exterior interfaces. Furthermore, we have shown that it is possible to soften the wall on demand to permit active filling with ingredients such is doxorubicin (a cancer killer), to lock in the ingredients by hardening the wall, and than to "re-open it" on demand to release the contents. We have also shown that it is possible to invert the vesicles by exchanging the interior and exterior interfaces. We now propose to explore a "breathing" mechanism in vesicles which allows them to increase or decrease their volume repeatedly by a factor of ca. 10x within ca. 1 minute. This would allow the uptake and release of ingredients very rapidly. We have also learned how to incorporate nanoparticles such as dendrimers within vesicles walls, and now propose to study systematically the inclusion of a number of different species, including catalysts into vesicle walls. In addition, we propose to examine the incorporation of species of specific geometry (e.g. spheres) into block copolymer aggregates and to study the effect of strong interactions on morphogenesis of the resulting aggregates. Several other minor studies are contemplated including the exploration of diffusion through vesicle walls and the entrapment of large molecules inside the cavities of vesicles.