Design of zwitterionic polyester based nano-carriers for platinum(IV) prodrug delivery

Zwitterions of L-cysteine have been applied to modify polyester, and the obtained zwitterionic polyester is employed to load a platinum(IV) drug to prolong the circulation time of the drug in blood and improve the stability of drug loading due to the good biocompatibility and antifouling properties. When used as multifunctional drug delivery vehicles, the nanoparticles not only exhibit a pH- and reduction-responsive drug release character, but also possess high ovarian cancer treatment efficiency in vitro. As compared to cisplatin, the IC50 value of the platinum(IV) drug loaded nanoparticles decreased by 57.44%, demonstrating that the platinum(IV) drug loaded nanoparticles exhibit strong toxicity to A2780 cells. In particular, in this study, aliphatic amine highly selective dye 5(6)-carboxyfluorescein N-succinimidyl ester is first used to label the drug-loaded zwitterionic nanoparticles, aiming to trace the location of the nanoparticles in cancer cells. All these results demonstrate potential applications of this type of zwitterionic nanostructure in biomedical fields.