RESUMO
The synthesis of well-defined propargyl-functional aliphatic polycarbonates is achieved via the organocatalytic ring-opening polymerization of prop-2-yn-1-yl 2-oxo-1,3,6-dioxazocane-6-carboxylate (P-8NC) using a wide variety of commercially available or readily made, shelf-stable organocatalysts. The resulting homopolymers show low dispersities and end-group fidelity, with the versatility of the system being demonstrated by the synthesis of telechelic copolymers and block copolymers with molar mass up to 40 kDa.
Assuntos
Alcinos , Cimento de Policarboxilato , Carbonatos , PolimerizaçãoRESUMO
The physical properties of cyclic and linear polymers are markedly different; however, there are few examples which exploit these differences in clinical applications. In this study, we demonstrate that self-assemblies comprised of cyclic-linear graft copolymers are significantly more stable than the equivalent linear-linear graft copolymer assemblies. This difference in stability can be exploited to allow for triggered disassembly by cleavage of just a single bond within the cyclic polymer backbone, via disulfide reduction, in the presence of intracellular levels of l-glutathione. This topological effect was exploited to demonstrate the first example of topology-controlled particle disassembly for the controlled release of an anti-cancer drug in vitro. This approach represents a markedly different strategy for controlled release from polymer nanoparticles and highlights for the first time that a change in polymer topology can be used as a trigger in the design of delivery vehicles. We propose such constructs, which demonstrate disassembly behavior upon a change in polymer topology, could find application in the targeted delivery of therapeutic agents.