Thionine in the design of new photosensitizers: Bromination and vehiculization in polymeric nanoparticles

GUALDESI, M.S.; VARA, J.; AIASSA, V.; ALVAREZ IGARZABAL, C.I.; ORTIZ, C.S.

JOURNAL OF MOLECULAR LIQUIDS

ELSEVIER SCIENCE BV

Año: 2020 vol. 310

0167-7322

o face the challenges of optimizing the properties of the photosensitizers currently used in the photodynamic inactivation of various microorganisms, we propose the bromination of thionine and the use of polymeric nanoparticles for the entrapment of halogenated derivative. Within this framework, the dibrominated derivative of thionine was synthesized and characterized. This new compound showed a high chemical and photochemical stability. In addition, bromination decreased the ionization constant and increased the aggregation of this photosensitizer in an aqueous medium. For this reason, the new compound showed a lower quantum yield of singlet oxygen production. However, the dibrominated thionine showed greater cell damage after photodynamic treatment. In order to prevent or decrease the aggregation of the photosensitizer in an aqueous medium, it was vehiculized in different polymeric polyacrylamide nanoparticles. In general, the vehiculization of the photosensitizers (PSs) in nanosize