Thesis (M.Sc.) - Cairo University - National Institute for Laser Enhanced Sciences - Department of Laser Applications In Environmental Metrology Photochemistry and Photobiology

Using nanoplatforms as carriers for photosensitizers has been found to enhance the efficacy of photodynamic therapy by improving bioavailability, preventing drug aggregation, and enhancing photosensitizer solubility to obtain a high therapeutic outcome. In this study, the photodynamic cytotoxicity of methylene blue (MB) loaded on hydroxyapatite nanoparticles (HA) was tested against osteosarcoma cancer cell line, Saos-2. HA and HA loaded with methylene blue (HA-NPs-MB) were prepared by chemical precipitation method. The prepared HA and HA-NPs-MB were characterized by TEM, Zeta potential, FTIR, and XRD. TEM images revealed that HA nanoparticles have a rod shape with a diameter around 14 to 17 nm and length around 46 to 64nm. FTIR and zeta potential confirmed the adsorption of cationic MB on HA. XRD pattern was identical to the standard XRD pattern of hydroxyapatite nanoparticles. Incubation of Saos-2 cells for 24 hours with of HA-NPs-MB and then irradiation of cells for 5 minutes with laser emitting diode at 800 nm, causes a reduction of cell viability (determined by MTT assay) more than the free methylene blue. The LC50 was 57.53 æg/ml and 86.99 æg/ml for HA-NPs-MB and free MB, respectively. Thus, nanoformulation of MB greatly reduced the dose of methylene blue required for effective photodynamic therapy. In the absence of laser, no cytotoxicity was observed for either HA-NPs-MB or free MB. No cytotoxicity was detected after incubation of cells with HA in the presence or the absence of laser. This study also investigated the mode of cell death after incubation of cells with free MB and HA-NPs-MB then exposure to laser radiation

Issued also as CD