Synthesis of ZnPc loaded poly(methyl methacrylate) nanoparticles via miniemulsion polymerization for photodynamic therapy in leukemic cells

The goal of this work was to synthesize and characterize ZnPc loaded poly(methyl methacrylate) (PMMA) nanoparticles (NPs) by miniemulsion polymerization. Biocompatibility assays were performed in murine fibroblast (L929) cells and human peripheral blood lymphocytes (HPBL). Finally, photobiological assays were performed in two leukemic cells: chronic myeloid leukemia in blast crisis (K562) and acute lymphoblastic leukemia (Jurkat). ZnPc loaded PMMA NPs presented an average diameter of 97±2.5 nm with a low polydispersity index and negative surface charge. The encapsulation efficiency (EE %) of ZnPc PMMA NPs was 87%±2.12. The release of ZnPc from PMMA NPs was slow and sustained without the presence of burst effect, indicating homogeneous drug distribution in the polymeric matrix. NP biocompatibility was observed on the treatment of peripheral blood lymphocytes and L929 fibroblast cells. Phototoxicity assays showed that the ZnPc loaded in PMMA NPs was more phototoxic than ZnPc after activation with visible light at 675 nm, using a low light dose of 2J/cm(2) in both leukemic cells (Jurkat and K562). The results from fluorescence microscopy (EB/OA) and DNA fragmentation suggest that the ZnPc loaded PMMA NPs induced cell death by apoptosis. Based on presented results, our study suggests that PDT combined with the use of polymeric NPs, may be an excellent alternative for leukemia treatment.