The same group reported another synthetic strategy to produce ester linker-containing polymer prodrug micelles for cisplatin delivery, via the use of methacrylate monomers with 1,3dicarboxylate functional groups as bifunctional chelator for platinum drugs. Sequential RAFT polymerization of OEGMA and 1,1-di-tert-butyl 3-(2-(methacryloyloxy)ethyl) butane-1,1,3tricarboxylate (MAETC) with varying spacer lengths gave diblock copolymers that were then conjugated to cis-diamminediaquaplatinum(II) (CDDP), resulting in amphiphilic copolymer prodrugs which formed micelles in aqueous solution (Figure ). Interestingly, increasing the length of the spacer improved the colloidal stability of the micelles without impacting on drug release kinetics. This cisplatin delivery system can also be made sensitive to pH by crosslinking it with either permanent or pH-sensitive ketal diamine crosslinkers, 94 with the aim of improving its colloidal stability, enabling better cellular uptake and higher cytotoxicity (Figure ). The synthesis strategy relied on synthesis of poly(oligo(ethylene glycol)methylether methacrylate)-block-poly(N-hyroxysuccinic methacrylate)-block-poly