【正文】
d to enter tumor cells and can be quickly cleared from the normal cells is particularly important, so that can not only improve the efficacy, but also reduce phototoxicity . In addition, develop long wavelength photosensitizer in order to increase the depth of illumination . Research the cause of photosensitizer selectivity and affinity for tumor cells and the mechanism of antitumor photosensitizer. These are the ing urgent problem.