Degradation and drug release profile of degradable core-corona type particles under acidic condition for cancer treatment

Abstract

Biodegradable particles are potential drug delivery carriers for cancer treatment because the drugs existed in inner core are released during the degradation of the particles. In this study, graft copolymers were prepared by radical copolymerization of 2-methylene-1,3-dioxepane and poly(ethylene glycol) monomethacrylate. Under acidic condition (pH 1.3), the graft copolymers were degraded through hydrolysis, and after 50-days of hydrolysis, they were converted to hydrophilic oligomers. Degradable core-corona-type particles were prepared by reprecipitation of the graft copolymer solution against water. Under acidic conditions, the diameter of the prepared particles decreased for one day due to the hydrolysis of the particles. The diameter increased after three days due to the swelling of the partially degraded particle cores containing poly(ethylene glycol) chains. Doxorubicin (DOX) release profile was evaluated in a PBS (pH 7.4) and acidic conditions (pH 1.3, 5.4). DOX was not released in PBS, whereas it was released under acidic conditions. The release of DOX increased at lower pH conditions. HeLa cells were cultured in the presence of DOX-loaded particles. Non-DOX-loaded particles showed no cytotoxicity whereas a decrease in cell viability was observed with increasing amounts of DOX-loaded particles. The prepared particles are expected to be useful as degradable drug delivery system carriers for cancer treatment.