Preparation of Supramolecular Graft Copolymers and the Subsequent Formation of pH-Sensitive Vesicles

摘要

A feasible methodology for the preparation of vesicles through self-assembly of supramolecular graft copolymers (SGPs) was developed. Two types of polymeric vesicles were prepared through self-assembly of two SGPs. For the first SGP, hydrophobic poly(4-vinylpyridine) (PVPy) were used as main chains, and hydrophilic poly(N-vinylpyrrolidone) with carboxylic end groups (PNVP-COOH) were grafted onto the main chains through ionic interaction between the carboxylic groups and pyridine groups. For the second SGP, hydrophobic poly(4-acrylamidobenzoic acid) (PABA) were used as main chains, and polyvinylpyrrolidone) with amino end groups were grafted onto the main chains through ionic interaction between the amino groups and carboxylic groups. Both SGPs could self-assemble to form vesicles in aqueous solution. The size of the vesicles prepared from the PVPy/PNVP-COOH (or PABA/PNVP-NH2) system could be controlled through modulation of the mass ratio of PVPy and PNVP-COOH (or PABA and PNVP-NH2). Both vesicles were sensitive to pH and could be deformed by changing pH. Drug-release studies showed that release rates of the loaded drug (sunset yellow) in the two vesicles could be well-controlled by the pH of the releasing solution.