Magnetic Targeting of mTHPC to Improve the Selectivity and Efficiency of Photodynamic Therapy

Photodynamic therapy (PDT) is a promising treatment for cancer. To date, PDT drugs are injected systemically, and the tumor area is irradiated to induce cell death. Current clinical protocols have several drawbacks, including limited accessibility to solid tumors and insufficient selectivity of drugs. Herein, we propose an alternative approach to improve PDT effectiveness by magnetic targeting of responsive carriers conjugated to the PDT drug. We coordinatively attached a meso-tetrahydroxyphenylchlorin (mTHPC) photosensitizer to Ce-doped-γ-Fe2O3 maghemite nanoparticles (MNPs). These MNPs are superparamagnetic and biocompatible, and the resulting mTHPC-MNPs nanocomposites are stable in aqueous suspensions. MDA-MB231 (human breast cancer) cells incubated with the mTHPC-MNPs showed high uptake and high rates of cell death after PDT. The exposure to external magnetic forces during the incubation period directed the nanocomposites to selected sites enhancing drug accumulation: double that of cells with no magn...