While polymeric spherical micelles have already proven to be extremely useful for therapeutic applications, worm micelles with a much larger core volume for encapsulation show significant potential for drug delivery because they are able to flow readily through pores and circulate much longer than spherical object in blood. One seemingly novel strategy would be to generate, spherical micelles from degradable worm micelles. We have prepared giant and flexible worm micelles self-assembled from amphiphilic diblock poly(ƒ'-caprolactone)-block-poly(ethylene oxide) (denoted as OCL). The OCL worm micelles are observed to spontaneously shorten and generate spherical micelles, due to hydrolytic degradation of the PCL core. Molecular degradation mechanisms and kinetics were explored. The degradation rate is affected by temperature, pH as well as the molecular weight of the polymer. Initial evaluations of OCL worm micelles show that they are capable of encapsulating hydrophobic drug and achieve a prolonged release till completion. More interestingly, the release profile is affected by OCL worm micelle degradation rate, providing an useful tool to control/trigger drug release.
Back to Nanoparticles, Microparticles and Vesicles
Back to The 37th Middle Atlantic Regional Meeting (May 22-25, 2005)