Freitas L F, Hamblin M R, Anzengruber F, Perussi J R, Ribeiro A O, Martins V C A, Plepis A M G
Programa de Pós-Graduação Interunidades Bioengenharia - University of Sao Paulo, São Carlos, SP, Brazil.
Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, United States.
J Photochem Photobiol B. 2017 Aug;173:181-186. doi: 10.1016/j.jphotobiol.2017.05.037. Epub 2017 May 30.
Studies indicate that hyperthermic therapy using gold nanorods and photodynamic activity with many photosensitizers can present a synergistic effect, and offer a great therapeutic potential, although more investigation needs to be performed before such approach could be implemented. We proposed to investigate the effect of the attachment of phthalocyanines on the surface of gold nanorods (well-characterized devices for hyperthermia generation) for the elimination of melanoma, one of the most important skin cancers due to its high lethality. Following the synthesis of nanorods through a seed-mediated method, the efficacy of photodynamic therapy (PDT) and hyperthermia was assessed separately. We chose to coat the nanorods with two tetracarboxylated zinc phthalocyanines - with or without methyl-glucamine groups. After the coating process, the phthalocyanines formed ionic complexes with the cetyltrimethylammonium bromide (CTAB) that was previously covering the nanoparticles. The nanorod-phthalocyanines complexes were analyzed by transmission electron microscopy (TEM), and their singlet oxygen and hydroxyl radical generation yields were assessed. Furthermore, they were tested in vitro with melanotic B16F10 and amelanotic B16G4F melanoma cells. The cells with nanoparticles were irradiated with laser (at 635nm), and the cell viability was assessed. The results indicate that the photodynamic properties of the phthalocyanines tested are enhanced when they are attached on the nanorods surface, and the combination of PDT and hyperthermia was able to eliminate over 90% of melanoma cells. This is a novel study because two tetracarboxylated phthalocyanines were used and because the same wavelength was irradiated to activate both the nanorods and the photosensitizers.
研究表明，使用金纳米棒的热疗和多种光敏剂的光动力活性可呈现协同效应，并具有巨大的治疗潜力，尽管在实施这种方法之前还需要进行更多研究。我们提议研究酞菁附着在金纳米棒（用于产生热疗的特性良好的器件）表面对消除黑色素瘤的影响，黑色素瘤是最重要的皮肤癌之一，因其高致死率。通过种子介导法合成纳米棒后，分别评估了光动力疗法（PDT）和热疗的疗效。我们选择用两种四羧基化锌酞菁包覆纳米棒——一种带有甲基葡糖胺基团，另一种没有。包覆过程后，酞菁与先前覆盖纳米颗粒的十六烷基三甲基溴化铵（CTAB）形成离子络合物。通过透射电子显微镜（TEM）分析了纳米棒 - 酞菁络合物，并评估了它们的单线态氧和羟基自由基产生率。此外，在体外对黑色素瘤B16F10细胞和无黑色素B16G4F黑色素瘤细胞进行了测试。用激光（635nm）照射含有纳米颗粒的细胞，并评估细胞活力。结果表明，测试的酞菁附着在纳米棒表面时其光动力特性增强，并且PDT和热疗的联合能够消除超过90%的黑色素瘤细胞。这是一项新颖的研究，因为使用了两种四羧基化酞菁，并且使用相同波长照射来激活纳米棒和光敏剂。
