Loading and Controlled Releasing of Anti-cancer Drug Bortezomib by Glucose-Containing Diblock Copolymer

A glucose-containing diblock copolymer was employed as nanocarrier in this study for delivery of the anticancer drug bortezomib (BTZ). Our system was based on pH-induced dynamical conjugation of boronic acid on BTZ to cis-diols on glucose-containing polymer. Diblock copolymer poly(ethylene glycol)-b-poly (gluconamidoethyl methacrylate) (PEG-PGAMA), was firstly synthesized via atom transfer radical polymerization(ATRP) by successive polymerization of monomer gluconamidoethyl methacrylate (GAMA) using a PEG-based ATRP macroinitiator. BTZ was then loaded in glucose-containing copolymer as chemical conjugation occurred of boronic acid to glucose groups and the drug-released behavior of this system was simulated in vitro. The results demonstrated that PEG-PGAMA copolymer had strong ability to bind BTZ at physiological pH of 7.4; it could also effectively release BTZ at acid pH of 5.5(close to environment of cancer tissue or the subcellular endosome) in a pH-dependent manner. In our study, a facile and interesting nanocarrier system for anti-cancer drug bortezomib (BTZ) was provided with a kind of glucose-containing block copolymer without any need of chemical modification, which only utilized dynamic chemical complexation to reach effective drug-loading and controlled release of BTZ upon responsiveness to external pH.