Autor(es)

Martin, Matheus Torelli ; Becceneri, Amanda Blanque ; Ford, Peter C. ; da Silva, Roberto Santana

• Tipo de documento: Artigo Científico
• Fonte: Inorganic Chemistry Communications; v. 161, p. 9-pg., 2024-01-31.

Resumo

Porphyrins, which display unique and versatile photochemical and photophysical properties, are widely used as photosensitizers (PS) in Photodynamic Therapy (PDT). Here, we have synthesized and evaluated the photodynamic properties of a new porphyrin complex, {TPyP[Ru(NO2)(bpy)2]4}4+, here designated complex I, where TPyP = 5,10,15,20-tetra(4-pyridyl)porphyrin and bpy = 2,2 ' bipyridine. This complex consists of a porphyrin ring bearing nitro-ruthenium groups coordinated by pyridyl bridges. Upon irradiation at 415 nm, the complex I produced singlet oxygen, 1 Delta g O2 (phi Delta = 0.29), and released NO from its nitro-ruthenium moieties (phi NO = 2.63 x 10-5). The fluorescence quantum yield of complex I (phi f = 4.8 x 10-3) was lower than that of the precursor free porphyrin TPyP (compound II) 5.1 x 10-2) and had a shorter fluorescence lifetime (tau f = 7.4 and 10.0 ns, respectively). The lower fluorescence quantum yield of complex I was expected: the outlying nitro-ruthenium groups promoted non-radiative energy dissipation. As for the triplet lifetime decay, complex I displayed two decay lifetimes (tau T1 = 36 and tau T2 = 722 mu s), shorter than the triplet lifetime of compound II (tau T = 987 mu s). Assays performed with the B16-F10 melanoma cell line showed little cytotoxicity from complex I (0-50 mu M) in the dark. However, under photolysis at 415 nm (4 J cm-2), complex I was highly cytotoxic: IC50 was 0.47 +/- 0.12 mu M. Under the same conditions, cis-[Ru(NO2)(bpy)2(py)]+ (complex III) showed no photocytotoxicity. Therefore, we conclude that the photocytotoxicity of complex I stemmed from the combination of NO release with 1 Delta g O2 production in tumor cells. (AU)

• Processo FAPESP: 22/15336-3 - Complexos de rutênio e tratamento baseado em excitação eletrônica: uma abordagem mecanicista centrada na avaliação citotóxica por irradiação luminosa, raios-X e ultrassom em linhagens de células cancerígenas 2D e 3D
• Beneficiário: Roberto Santana da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 20/03367-6 - Fototerapia utilizando complexos rutênio-ftalocianinas como geradores de espécies reativas de oxigênio e nitrogênio: estudo do mecanismo de ação in vitro em diferentes modelos 2D e 3D de células cancerígenas
• Beneficiário: Amanda Blanque Becceneri
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado