Adams Dave J, Adams Sarah, Atkins Derek, Butler Michael F, Furzeland Steve
Unilever Corporate Research, Colworth, Sharnbrook, Bedford, MK44 1LQ, United Kingdom.
J Control Release. 2008 Jun 4;128(2):165-70. doi: 10.1016/j.jconrel.2008.03.006. Epub 2008 Mar 14.
Vesicles prepared from block copolymers have been mooted for the encapsulation of water-soluble molecules. This is because the membranes of polymer vesicles have been shown to be more stable than those in vesicles formed from lipids, with the membrane properties being tuned by the length and nature of the hydrophobic block in the polymer. The generally accepted mechanisms of vesicle formation involve either wrap-up of a lamellar sheet or formation via a sequence of micelle to worm to disks to vesicles. These should lead to efficient encapsulation. Alternatively, a method involving phase separation followed by re-structuring has been recently suggested. Here, we show that this final mechanism holds for vesicles formed from a PEO-b-PDEAMA copolymer by a pH switch and that this mechanism leads to highly inefficient encapsulation on vesicle formation.
由嵌段共聚物制备的囊泡已被提议用于封装水溶性分子。这是因为聚合物囊泡的膜已被证明比脂质形成的囊泡的膜更稳定，其膜性质可通过聚合物中疏水嵌段的长度和性质来调节。普遍接受的囊泡形成机制包括层状片的包裹或通过一系列胶束到蠕虫状到盘状再到囊泡的形成。这些应该会导致有效的封装。另外，最近有人提出了一种涉及相分离然后重新构建的方法。在这里，我们表明，这种最终机制适用于通过pH转换由PEO-b-PDEAMA共聚物形成的囊泡，并且这种机制导致囊泡形成时的封装效率极低。
