Photodynamic effect of photosensitizer-loaded hollow silica nanoparticles for hepatobiliary malignancies: an in vitro and in vivo study

Background and aims: Nanoparticles have been explored recently as an efficient delivery system for photosensitizers in photodynamic therapy. In this study, polyhematoporphyrin (C 34 H 38 N 4 NaO 5 ,) was loaded into hollow silica nanoparticles (HSNP) by one-step wet chemical-based synthetic route. We evaluate the efficacy and safety of polyhematoporphyrin-loaded HSNP with hepatobiliary malignant cells and in vivo models. Methods: Human liver cancer, cholangiocarcinoma and gallbladder cancer cells were cultured with the HSNP and cellular viability was determined by MTT assay. Apoptotic and necrotic cells were measured by flow cytometry. Finally, we investigate its effect in vivo. Results: In MTT assay, the cell viability of QBC939, Huh-7, GBC-SD and HepG2 cells of the HSNP was 6.4±1.3%, 6.5±1.2%, 3.7±1.2% and 4.7±2.0%, respectively, which were significant different from that of free polyhematoporphyrin 62.4±4.7%, 62.5±6.0%, 33.4±6.5% and 44.3±1.9%. Flow cytometry demonstrated the laser-induced cell death with polyhematoporphyrin-loaded HSNP was much more severe. Similarly, in vivo results of each kind of cell revealed 14 days post-photoradiated, tumor sizes of the HSNP group were significantly smaller. Administration of the HSNP without illumination cannot cause killing effect both in vitro and in vivo experiments. Conclusions: HSNP is a desirable delivery system in photodynamic therapy for hepatobiliary malignacies, with improved aqueous solubility, stability and transport efficiency of photosensitizers.