A
photosensitizer is a molecular
drug for photodynamic diagnosis and
photodynamic therapy (
PDT) against
cancer. Many studies have developed
photosensitizers, but improvements in their cost, efficacy, and side effects are needed for better
PDT of patients. In the present study, we developed a novel
photosensitizer β-
mannose-conjugated
chlorin e6 (β-M-Ce6) and investigated its
PDT effects in human
glioblastoma U251 cells. U251 cells were incubated with β-M-Ce6, followed by
laser irradiation. Cell viability was determined using the Cell Counting Kit-8 assay. The
PDT effects of β-M-Ce6 were compared with those of
talaporfin sodium (TS) and our previously reported
photosensitizer β-
glucose-conjugated
chlorin e6 (β-G-Ce6). Cellular uptake of each
photosensitizer and subcellular distribution were analyzed by fluorescence microscopy. β-M-Ce6 showed 1000× more potent
PDT effects than those of TS, and these were similar to those of β-G-Ce6. β-M-Ce6 accumulation in U251 cells was much faster than TS accumulation and distributed to several organelles such as the Golgi apparatus, mitochondria, and lysosomes. This rapid cellular uptake was inhibited by low temperature, which suggested that β-M-Ce6 uptake uses
biological machinery. β-M-Ce6 showed potent
PDT anti-
cancer effects compared with clinically approved TS, which is a possible candidate as a next generation
photosensitizer in
cancer therapy.