GSH-triggered disintegrable hyperbranched polymer prodrug as unimolecular micelles for tumor-specific chemotherapy

Unimolecular micelles have attracted great interest in tumor chemotherapy owing to their superior stability. Here, a GSH-triggered disintegrable hyperbranched polymer prodrug (HBPP-DOX) was designed via the self-condensing vinyl polymerization (SCVP) of a reduction-sensitive monomer prodrug (MA-SS-DOX) with a reduction-sensitive inimer (MA-SS-Br), in which polyethylene glycol monomethyl ether methacrylate (PEGMA) was used as a comonomer to introduce hydrophilic brushes. The proposed HBPP-DOX with a high drug content of 32% could easily self-assemble into unimolecular micelles, which could completely disintegrate and release the drug into tumor cells triggered by the high GSH level therein, showing excellent tumor-specific cytotoxicity with enhanced tumor growth inhibition.