Figure 5.

(A) Examples of bonds utilized in the synthesis of biodegradable polymer-drug conjugates. Biodegradation typically occurs via hydrolysis (via reduction for disulfides). (B) Overall strategy for the synthesis of multiblock polyHPMA copolymers. HPMA copolymer blocks are linked together via lysosomally degradable Gly-Phe-Leu-Gly (GFLG) linkages introduced via a combination of RAFT polymerization and click chemistry. Reprinted with permission from [137], J. Yang, et al., Synthesis of biodegradable multiblock copolymers by click coupling of RAFT-generated heterotelechelicpolyhpma conjugates. Reactive and Functional Polymers 71, 294 (2011). © 2011, Elsevier.