Herein, we report a versatile approach for the synthesis of aqueous suspensions of degradable polymer prodrug nanoparticles by rROPISA (Figure ). It relies on the chain extension of a biocompatible solvophilic block by a combination of vinyl monomers, CKAs and drug-monomers, and allowed for the preparation of stable and narrowly dispersed polymer prodrug nanoparticles featuring adjustable drug loading, hydrolytic degradation and significant cytotoxicity on cancer cells. The versatility of this process was illustrated by its application to degradable polymer prodrug nanoparticles based on two different anticancer drugs, gemcitabine (Gem) and paclitaxel (Ptx), which are both widely used clinically against different types of cancers, under the names Gemzar and Taxol, respectively. Moreover, the polymer prodrug nanoparticles were readily fluorescently labeled for imaging purposes by insertion of fluorescent moieties in the copolymer backbone during the rROPISA process.