Photo- and X-ray Induced Cytotoxicity of CeF₃-YF₃-TbF₃ Nano-Particle- Polyvinylpyrrolidone –“Radachlorin” Composites for Combined Photodynamic Therapy

Abstract

The Ce0.5Y0.35Tb0.15F3 nanoparticles with CeF3 hexagonal structure were synthesized by co-precipitation technique. The average nanoparticle diameter was 14±1 nm. The luminescence decay curves of Ce0.5Y0.35Tb0.15F3 nanoparticles (λem = 541 nm, 5D4 – 7F5 transition of Tb3+) conjugated with Radachlorin by means of polyvinylpyrrolidone coating as well as without Radachlorin were detected. Efficient nonradiative energy transfer from Tb3+ to the Radachlorin was demonstrated. The maximum energy transfer coefficient for nanoparticles conjugated with Radachlorin via polyvinylpyrrolidone and without the coating were 82% and 55%, respectively. The average distance between nanoparticle surface and Radachlorin was R0 =4.5 nm. The best results for X-ray induced cytotoxicity was observed for NP-PVP-Rch sample at the lowest Rch concentration. In particular, after X-ray irradiation the survival A 549 human lung carcinoma cells decreased by ~12%.