A magnetic nanoparticle functionalized reduced graphene oxide-based drug carrier system for a chemo-photodynamic cancer therapy

Combination therapy has gained increasing attention for the treatment of cancer. In this study, a versatile reduced graphene oxide (rGO)-based drug delivery system (DDS) was developed for chemophotodynamic cancer therapy. The reduced graphene oxide surface was decorated with magnetic nanoparticles (MNPs) and camptothecin (CPT) chemo drug. The photosensitizer 4-hydroxycoumarin (4-HC) was cross-linked with rGO via an allylamine (AA) linker. The CPT-loaded MrGO-AA-g-4-HC was characterized via FT-IR, SEM, HR-TEM, XRD, AFM, and DLS techniques. The CPT-loaded nanocarrier exhibits a pH-sensitive drug-release behavior and it was investigated using a UV-Visible spectrophotometer at the lambda(max) value of 263 nm for CPT and 353 nm for 4-HC. The cytotoxic effects of CPT and 4-HC loaded carriers show higher toxicity effect against the human breast cancer cell line (MCF-7) compared with the normal fibroblast cell line (WS-1). The 365 nm laser irradiation of 20 mW cm(-2) for 3 min on CPT-loaded MrGO-AA-g-4-HC could be efficacious in absorbing the UV-light for 4-HC excitation to produce a higher amount of reactive oxygen species (ROS) for higher inhibition towards MCF-7 cells; the combined treatment exhibits outstanding cell apoptosis that leads to cell death. In vivo anti-tumor effects established that CPT-loaded MrGO-AA-g-4-HC could exhibit excellent synergistic anti-tumor efficiency, which is better than monotherapy. Thus, this work presents a new nano-platform for the loading of both chemo drug and photosensitizers with high loading ability for the synergistic effect of chemophotodynamic cancer treatment.