Mechanisms of hypericin incorporation to explain the photooxidation outcomes in phospholipid biomembrane models

Autor(es)

Pereira, Lucas S. A. ; Camacho, Sabrina A. ; Almeida, Alexandre M. ; Goncalves, Renato S. ; Caetano, Wilker ; DeWolf, Christine ; Aoki, Pedro H. B.

• Tipo de documento: Artigo Científico
• Fonte: Chemistry and Physics of Lipids; v. 244, p. 11-pg., 2022-02-23.

Resumo

Cell membranes are the first barriers for drug binding and key for the action of photosensitizers (PS). Herein, we report on the incorporation of the PS hypericin into Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) to represent eukaryotic cell membranes, and 1,2-dioleoyl-sn-glycero-3-phospho(1'-rac-glycerol) (DOPG) to mimic bacterial membranes. Surface pressure (pi) vs mean molecular area (angstrom) isotherms showed a high degree of interaction (binding, penetration and relative solubilization) of hypericin into DPPC and DOPC monolayers. On the other hand, electrostatic repulsions govern the interactions with DOPG and DOPS, favoring hypericin self-aggregation, as visualized by Brewster angle microscopy (BAM). Indeed, the larger domains in BAM were consistent with the greater expansion of DOPG monolayers with incorporated hypericin, owing to stronger electrostatic repulsions. In contrast to DPPC, light-irradiation of DOPC monolayers containing hypericin induced loss of material due to hydrocarbon chain cleavage triggered by contact-dependent reactions between triplet excited state of hypericin and chain unsaturations. The mild effects noted for both irradiated DOPS and DOPG monolayers are attributed to hypericin self-aggregation, which may have decreased the singlet oxygen quantum yield (Phi O-1(2)) via self-quenching, despite the increased instability induced in the monolayers. (AU)

• Processo FAPESP: 18/16713-0 - Terapia fotodinâmica: de efeitos moleculares em sistemas modelos a eficiência fotodinâmica em cultivo celular
• Beneficiário: Pedro Henrique Benites Aoki
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/08077-6 - Foto oxidação de monocamadas de Langmuir mediada pelo fotossensibilizador hipericina
• Beneficiário: Lucas Sant Anna Pereira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Iniciação Científica
• Processo FAPESP: 18/22214-6 - Rumo à convergência de tecnologias: de sensores e biossensores à visualização de informação e aprendizado de máquina para análise de dados em diagnóstico clínico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/14692-5 - Terapia fototérmica mediada por nanopartículas de ouro: de sistemas modelos de biomembranas ao cultivo in vitro de células tumorais
• Beneficiário: Sabrina Aléssio Camacho
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado