Polymeric nanoparticles loaded with new photosensitizer for effective photoinactivation of Staphylococcus aureus

GUALDESI MARÍA S; VARA JIMENA; PEREYRA, L.; AIASSA VIRGINIA; ALVAREZ IGARZABAL CECILIA I; ORTIZ CRISTINA S

Córdoba

Congreso; 6° Reunión Internacional de Ciencias Farmacéuticas; 2021

The novel photosensitizer (PS) dibrominated thionine (ThBr2) has potential application in photodynamic therapy, although it presents certain drawbacks. To reduce its aggregation in aqueous medium and enhance its production of singlet oxygen (1O2), the new halogenated derivative was encapsulated in three previously synthesized poly(acrylamide) nanoparticles (PAA-NPs). The use of PAA-NPs as PS nanocarriers proved to be a valuable tool to enhance the antimicrobial efficacy of different PSs and protect them from possible degradation under physiological conditions. The results obtained showed that the PS was successfully encapsulated, and PAA-NPs presented ideal sizes and polydispersity indexes. In addition, the vehiculization of the PS in the NPs caused a significant decrease in the higher-order aggregate, which was reflected in the increase in the 1O2 yield of these systems compared to that of the free form. ThBr2 free and loaded into the three PAA-NP, was tested against different strains of Staphylococcus aureus in order to determine its ability to inactivate these microorganisms. The nanoparticle formed with the monomer hydroxyethyl methacrylate showed the best photodynamic efficacy. The results obtained clearly suggest that polyacrylamide nanoparticles loaded with photosensitizers of the thiazine family have great potential for further application in antimicrobial photodynamic therapy.