| Photodynamic therapy (PDT) is a potential new approach for treatment of malignant tumors. This treatment involves three elements, light, oxygen and photosensitizer which plays a decisive role. One of the PSs most widely used in PDT is phthalocyanine (Pc) because of their strong absorption in the phototherapeutic window, high singlet oxygen generation efficiency, and high photodynamic activities for inactivation of different tumour cell lines. However, it was found that the poor water solubility of Pcs can interfere with their PDT efficacy and decrease the fluorescence of the Pcs.1. Three kinds of lipophilic phthalocyanines as goals, a series of drug delivery systems were built by sol-gel method and microemulsion method. The average size of phthalocyanine/SiO2, prepared by sol-gel way, drug delivery system was150-200nm; and the average size of phthalocyanine/SiO2, prepared by micro-emulsion way, drug delivery system was100-150nm;2. After embedded inside the silica nanoparticles, the water-solubility, stability and monomer percent of phthalocyanine in water were greatly improved comparing with the free phthalocyanines, and therefore, its photo-induced singlet oxygen generation efficacy of drug-doped silica nanoparticles was improved.3. The stability was phthalocyanine/SiO2drug delivery systems were quite stable in aqueous solutions.4. The in vitro experiments indicated that such silica nanospheres containing phthalocyanine can be efficiently taken up by HeLa cells, and light irradiation of such impregnated cells might result in significant cell death.Thus, these properties indicated that Pc-silica nanospheres could possibly make it especially promising to be used in clinical photodynamic therapy. |
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