A comparison of covalent and noncovalent strategies for paclitaxel release using poly(ester amide) graft copolymer micelles

© 2015 Published by NRC Research Press. Micelles formed from amphiphilic copolymers are promising for the delivery of drug molecules, potentially leading to enhanced properties and efficacies. Critical aspects of these systems include the use of biocompatible, biodegradable polymer backbones as well as the ability to control the incorporation of drugs and their release rates. In this work, a poly(ester amide)-poly(ethylene oxide) graft copolymer with paclitaxel conjugated via ester linkages was prepared and assembled into micelles. For comparison, micelles with physically encapsulated paclitaxel were also prepared. The release rates of these two systems were studied, and the micelles with covalently conjugated paclitaxel exhibited a prolonged release of the drug in comparison to the noncovalent system, which rapidly released the payload. In vitro studies suggested that the poly(ester amide)-poly(ethylene oxide) copolymers were nontoxic, whereas the toxicities of the drug-loaded micelles were dependent on their release rates. Overall, these systems are promising for further development as anticancer drug carriers