Investigation of water-soluble x-ray luminescence nanoparticles for photodynamic activation

In this letter, we report the synthesis of La F3: Tb3+ -meso-tetra(4- carboxyphenyl) porphine (MTCP) nanoparticle conjugates and investigate the energy transfer as well as singlet oxygen generation following x-ray irradiation. Our observations indicate that La F3: Tb3+ -MTCP nanoparticle conjugates are efficient photodynamic agents that can be initiated by x-rays at a reasonably low dose. The addition of folic acid to facilitate targeting to folate receptors on tumor cells has no effect on the quantum yield of singlet oxygen production in the nanoparticle-MTCP conjugates. Our pilot studies indicate that water-soluble scintillation nanoparticles can potentially be used to activate photodynamic therapy as a promising deep cancer treatment modality.