Phospholipid multilamellar vesicles entrapping phenothiazine photosensitizers. Preparation, characterization and evaluation of their photodynamic properties

VARA, JIMENA; SANCHEZ, JULIETA M.; PERILLO, MARÍA A.; ORTIZ, CRISTINA S.

JOURNAL OF MOLECULAR LIQUIDS

ELSEVIER SCIENCE BV

Año: 2019 vol. 273 p. 147 - 147

0167-7322

he aim of the present paper was to optimize the properties of phenothiazine photosensitizers (PSs), Azure B and its monobrominated derivative. They were entrapped in multilamellar liposomes of egg phosphatidylcholine (EPC) and dipalmitoylphosphatidylcholine (dpPC). The higher partition coefficient of both PSs in the EPC/water system compared with that of both PSs in the dpPC/water system allowed the selection of EPC to be used for the development of third generation photosensitizers. The optimal phospholipid/phenothiazine ratio and the location of these dyes in the lipid bilayer systems were established. These dyes were found to be located within the polar head group region of the lipid bilayer, which would enhance the effectiveness of the irradiation procedure. In addition, the encapsulation of both photosensitizers in liposomes led to a decrease in the aggregation of these compounds, and consequently to an increase in their singlet oxygen quantum yield (ϕΔ). The encapsulat