Intracellular GSH-responsive camptothecin delivery systems
Drug delivery systems (DDSs) are invaluable in the scientific field on account of their groundbreaking progress in nanomedicine, which are composed of various nanocarriers, drugs, and the linkers integrating the carriers and drugs. As an effective anticancer medicine, camptothecin (CPT) has been proved to obviously inhibit the cyclic processes of DNA related to replication and transcription through the stable combination with topoisomerase I and DNA. To date, the structural modification of CPT has been carried out at different sites to increase anticancer activity and study the antitumor mechanisms. Nevertheless, due to the hydrophobicity, instability and severe systemic toxicities of CPT, it is feasible to connect nanostructured materials and targeted moieties to CPT, giving rise to advanced smart DDSs whose features and functionality can be tailored to satisfy specific clinical needs. This review describes recent advances in intracellular glutathione (GSH)-controlled DDSs to release CPT. We also emphasize the size, composition and synthesis of the carriers and the linkers between the carriers and CPT, mechanisms of drug release and anticancer efficacies in vitro and in vivo.