Application of Titanium Dioxide (TiO[sub 2]) Nanoparticles in Photodynamic Therapy (PDT) of an Experimental Tumor

Nano‐sized particles has been used for the photodynamic and sonodynamic treatments of pre‐clinical cancer study in previous studies [1–7]. In this study, the 5‐aminolevulinic acid (5‐ALA) solution mixed with TiO2 nanoparticles was oral‐administrated into the nude mouse transplanted under the skin with a human prostate cancer cell line. The experimental tumor model tissue (7×7×7 mm3) was measured of the size at different times after the photodynamic therapy (PDT) by laser to take a growth curve of the tumor. The treatment efficacy was jugged from the growth curves comparing different conditions. In the presence of the nanoparticle, the PDT treatment effect was enhanced those in the absence of the particles. Furthermore, the sonodynamic therapy (SDT) effect also enhanced with the nanoparticle to produce more OH radicals by ultrasound irradiation. These combination therapy of PDT and SDT with nanoparticles was very effectively resulted to be useful as a clinical use in future.