Castro Kelly A D F, Prandini Juliana A, Biazzotto Juliana Cristina, Tomé João P C, da Silva Roberto S, Lourenço Leandro M O
Department of Biomolecular Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Centro de Química Estrutural, Institute of Molecular Sciences & Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Front Chem. 2022 Mar 14;10:825716. doi: 10.3389/fchem.2022.825716. eCollection 2022.
Phthalocyanine (Pc) dyes are photoactive molecules that can absorb and emit light in the visible spectrum, especially in the red region of the spectrum, with great potential for biological scopes. For this target, it is important to guarantee a high Pc solubility, and the use of suitable pyridinium units on their structure can be a good strategy to use effective photosensitizers (PSs) for photodynamic therapy (PDT) against cancer cells. Zn(II) phthalocyanines (ZnPcs) conjugated with thiopyridinium units (1-3) were evaluated as PS drugs against B16F10 melanoma cells, and their photophysical, photochemical, and photobiological properties were determined. The photodynamic efficiency of the tetra- and octa-cationic ZnPcs 1-3 was studied and compared at 1, 2, 5, 10, and 20 µM. The different number of charge units, and the presence/absence of -F atoms on the Pc structure, contributes for their PDT efficacy. The 3-(4',5'-dimethylthiazol-2'-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays on B16F10 melanoma cells show a moderate to high capacity to be photoinactivated by ZnPcs 1-3 (ZnPc 1 > ZnPc 2 > ZnPc 3). The best PDT conditions were found at a Pc concentration of 20 μM, under red light ( = 660 ± 20 nm) at an irradiance of 4.5 mW/cm for 667 s (light dose of 3 J/cm). In these conditions, it is noteworthy that the cationic ZnPc shows a promising photoinactivation ratio, reaching the detection limit of the MTT method. Moreover, these results are comparable to the better ones in the literature.
酞菁（Pc）染料是光活性分子，能够在可见光谱中吸收和发射光，尤其是在光谱的红色区域，在生物学领域具有巨大潜力。为了实现这一目标，保证高Pc溶解度很重要，在其结构上使用合适的吡啶鎓单元可能是一种很好的策略，可用于开发针对癌细胞的光动力疗法（PDT）有效光敏剂（PSs）。对与硫代吡啶鎓单元（1-3）共轭的锌（II）酞菁（ZnPcs）作为抗B16F10黑色素瘤细胞的PS药物进行了评估，并测定了它们的光物理、光化学和光生物学性质。研究并比较了四阳离子和八阳离子ZnPcs 1-3在1、2、5、10和20 μM时的光动力效率。电荷单元数量的不同以及Pc结构上-F原子的存在与否，对它们的PDT疗效有影响。对B16F10黑色素瘤细胞进行的3-（4'，5'-二甲基噻唑-2'-基）-2，5-二苯基四氮唑溴盐（MTT）测定表明，ZnPcs 1-3（ZnPc 1 > ZnPc 2 > ZnPc 3）对其光灭活具有中等至高能力。最佳PDT条件是在Pc浓度为20 μM时，在红光（ = 660 ± 20 nm）下，辐照度为4.5 mW/cm，照射667 s（光剂量为3 J/cm）。在这些条件下，值得注意的是阳离子ZnPc显示出有前景的光灭活率，达到了MTT方法的检测限。此外，这些结果与文献中较好的结果相当。
