Singlet oxygen generation and dark toxicity of a nido- and a closo-carboranylporphyrin
The dark toxicity and singlet oxygen quantum yields of the zinc(II) complexes of the nido- and closo-carboranylporphyrins 4 and 5 are reported. Both carboranylporphyrins show very low toxicity towards V79 hamster lung fibroblast cells (IC50 > 500 μM), display similar absorption and fluorescence emission spectra, and are efficient producers of singlet oxygen (quantum yields of 0.72 in CD3OD and 0.45 in CHCl3 were determined for 4 and 5, respectively). Our results indicate that the presence of nido- or c/oso-carborane cages bound via methylene linkages to the meso-phenyl groups, do not substantially alter the photosensitizing properties of porphyrin macrocycles. It is suggested that carboranylporphyrins could have dual application in the boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) treatment of malignant brain tumors.
Publication Source (Journal or Book title)
Proceedings of SPIE - The International Society for Optical Engineering
Vicente, M., Gottumukkala, V., Wickramasinghe, A., Anikovsky, M., & Rodgers, M. (2004). Singlet oxygen generation and dark toxicity of a nido- and a closo-carboranylporphyrin. Proceedings of SPIE - The International Society for Optical Engineering, 5315, 33-40. https://doi.org/10.1117/12.531903