Photothermotherapy using porous silicon

초록

We report the in vitro cell test and in vivo animal test results of porous silicon (PSi) particles as a potential therapeutic agent used for cancer thermotherapy in combination with NIR. The in vitro cell test results show that both the cells exposed to NIR laser without PSi particles treatment and the cells treated with PSi particles but not with NIR irradiation have cell viabilities higher than 97 %. Combination of these two techniques, however, shows cell viability less than 1 %. The cell death rate strongly depends on the concentration of PSi. Also, the cell deaths are mostly due to necrosis but partly due to late apoptosis. The in vivo animal test results show that tumor cells can be completely destroyed without nearly giving damage to surrounding healthy cells by an injection of an adequate amount of PSi/NaCl suspension and a subsequent single continuous laser treatment at a moderately low laser illumination intensity for the exposure time optimized for the tumor size. These results suggest that PSi particles can be effectively utilized as a therapeutic agent for cancer thermotherapy due to their excellent photothermal property and high biocompatibility.