A wide range of block copolymer amphiphiles been shown over the last several years to self-assemble into polymer vesicles or 'polymersomes'. The larger the molecular weight of the copolymer, the more stable the polymersome, and so to introduce controlled release mechanisms we have been developing PEO-polyester based polymersomes. With time, the polyester blocks degrade and porate the vesicles. If one starts with slightly more symmetric copolymers than the polyester-rich diblocks needed for vesicles, cylinder micelles can be formed. With time, these cylinders also degrade as polyester chains hydrolyse. We will highlight the controlled release aspects of both these 'nano-transforming' systems and describe targeting as well as interactions with cells and, in some cases, surprisingly long circulation in the body.
Web Page: www.seas.upenn.edu/~discher
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Back to The 37th Middle Atlantic Regional Meeting (May 22-25, 2005)