Synthesis of Polyethylene Glycol-Poly(glycerol carbonate) Block Copolymeric Micelles as Surfactant-Free Drug Delivery Systems

We report the synthesis of block copolymers of monomethoxylatedpolyethylene glycol and poly(glycerol carbonate) (mPEG-b-PGC) via the ring-opening polymerization of benzyl glycidyl ether,monomethoxylated polyethylene glycol, and carbon dioxide using a cobaltsalen catalyst. The resulting block copolymers display high polymer/cycliccarbonate selectivity (>99%) and, if two oxirane monomers are used,random incorporation into the polymer feed. The resulting diblockmPEG-b-PGC polymer shows promise as a nanocarrierfor surfactant-free, sustained chemotherapeutic delivery. mPEG-b-PGC, with paclitaxel conjugated to the pendant primaryalcohol of the glycerol polymer backbone, readily forms 175 nm diameterparticles in solution and contains 4.6 wt % paclitaxel (PTX), whichis released over 42 days. The mPEG-b-PGC polymeritself is noncytotoxic, whereas the PTX-loaded nanoparticles are cytotoxicto lung, breast, and ovarian cancer cell lines.

Automated summary

This study describes the synthesis of mPEG-b-PGC block copolymers using a cobaltsalen catalyst via the ring-opening polymerization of benzyl glycidyl ether, monomethoxylated polyethylene glycol, and carbon dioxide. The resulting block copolymers exhibit high polymer/cyclic carbonate selectivity (>99%) and random incorporation of oxirane monomers. The diblock mPEG-b-PGC polymer shows promise as a nanocarrier for sustained chemotherapeutic delivery without the need for surfactants.