Reactive oxygen species (ROS)-responsive microspheres for targeted drug delivery of camptothecin

Non-selectivity of drugs used in the treatment of cancer inevitably leads to destruction of rapidly dividing normal healthy cells. In order to overcome this limitation a wide variety of targeted drug delivery systems have been reported. Among them, microparticulate drug delivery is a one of the most efficient routes and lacks responsiveness to external stimuli. In order to overcome this limitation a new drug delivery system based on reactive oxygen species (ROS) sensitive tween 80 coated magnetic iron oxide nanoparticles was developed. The rationale for this study is based on the literature reports that cancer cells accumulate oxygen free radicals at higher concentrations. The cancer chemotherapeutic agent camptothecin (CPT) was encapsulated in PLGA-PVA magnetic microspheres (CPT-MMSs) and its responsiveness to ROS was demonstrated by the specific release of camptothecin in the presence hydrogen peroxide. The experimental observations showed more marked cyto-toxicity in human cervical cancer (HeLa) cancer cells mediated by CPT-MMSs as compared to tween 80 coated magnetic iron oxide nanoparticles (MIONs) and CPT alone.