From elementary reactions to chemical relevance in the photodynamic therapy of cancer

Arnaut, Luis G.; Formosinho, Sebastião J.

doi:10.1351/PAC-CON-12-08-16

Pure Appl. Chem., 2013, Vol. 85, No. 7, pp. 1389-1403

http://dx.doi.org/10.1351/PAC-CON-12-08-16

Published online 2013-02-25

From elementary reactions to chemical relevance in the photodynamic therapy of cancer

Luis G. Arnaut^1,2 and Sebastião J. Formosinho¹*

¹ Chemistry Department, University of Coimbra, 3004-535 Coimbra, Portugal
² Luzitin SA, Ed. Bluepharma, S. Martinho do Bispo, 3045-016 Coimbra, Portugal

Abstract: Theories of radiationless conversions and of chemical processes were employed to design better photosensitizers for photodynamic therapy (PDT). In addition to photostability and intense absorption in the near infrared, these photosensitizers were required to generate high yields of long-lived triplet states that could efficiently transfer their energy, or an electron, to molecular oxygen. The guidance provided by the theories was combined with the ability to synthesize large quantities of pure photosensitizers and with the biological screening of graded hydrophilicities/lipophilicities. The theoretical prediction that halogenated sulfonamide tetraphenylbacteriochlorins could satisfy all the criteria for ideal PDT photosensitizers was verified experimentally.