الفهرس 
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Abstract
Curcumin is a natural pigment that generates singlet oxygen upon light excitation; hence it can be used as a photosensitizer in photodynamic therapy. The extremely low water solubility and poor systemic bioavailability make curcumin a challenging molecule to be used clinically. In this study two different delivery systems for curcumin were prepared: liposomes and PVP gold nanoparticles. Cur liposomes were prepared by lipid film hydration method. PVP capped gold nanoparticles were prepared using chloroauric acid as a metal precursor and trisodium citrate. The results showed that the Cur liposomes were spherical in shape of size 350±94 nm and uniform size distribution, had high encapsulation efficiency. Also, the results of Cur PVP gold nanoparticles showed that they were spherical in shape of size 23±2.22 nm. The UV-Vis spectrum of Cur PVP GNPs which shows two peaks, the first one at 408 nm and the second one at 525nm which confirms the characteristic peaks for the components in the Cur PVP GNPs complex are intact. In the FTIR spectrum of Cur conjugated with PVP capped gold nanoparticles, there is a shift of O-H (hydroxyl group). While in the FTIR spectrum of PVP GNPs and GNPs, there is a shift of C=O (carbonyl group) due to formation of intermolecular hydrogen bonding. Dark and photocytoxicity of Cur was measured as a function of Cur prepared formula (Cur DMSO, Cur PVP/H2O, Cur PVP GNPs and Cur liposomes), light fluence rate (100 and 200 mW/cm2 ), irradiation time (10 and 30 min) and Cur concentration (6 and 10 μg/ml). Cur formulas induced cell death and showed dark cytotoxicity in both concentrations (6 and 10 μg/ml), irradiation with blue light fluence rate 200 mW/cm2 significantly increase the cell death compared to dark. The antitumor activity of Cur in the two delivery systems was evaluated in vivo. The formulations were injected into the subcutaneously implanted Ehrlich tumor. Animals in all groups except control and LED group were injected with two doses of the prepared formulations intratumorally and received 70 mW ⁄ cm2 for 15 min blue light from light emitting diode (430 nm). It is clear from the results of in vivo study that Cur loaded in liposomes and conjugated with GNPs was superior to its free form. These results were confirmed by the histopathological examination. This study showed that liposomes and gold nanoparticles could be used as suitable delivery system for Cur, and that Cur may be developed as a potential photosensitizer, and a chemotherapeutic agent in clinical application.