Luminol as in situ light source in meso-tetraphenylporphyrin-mediated photodynamic therapy

The light sources used in current photodynamic therapy are mainly lasers or light emitting diodes, which are not suitable to treat large-volume tumors and those located in the inner body. To overcome the limitation, we propose an in situ light source to activate the photosensitizer and kill the cancer cells directly. In the present work, we use luminol as light source and meso-tetraphenylporphyrin as the photosensitizer. According to the results, cells incubated with meso-tetraphenylporphyrin, subsequently triggered by luminol, decreased significantly in assays including cell viability and cytotoxicity, while the other groups showed only minor differences. The flow cytometric and fluorescent microscopy analysis showed similar results as well. In the analysis of cell death pathway, cell shrinkage was noticed after photodynamic therapy treatment, which might refer to apoptosis. Briefly, we suggest that luminol is a promising light source in meso-tetraphenylporphyrin-mediated photodynamic therapy for its greater penetration depth and well matched emission wavelength.