a Medical Laser Research Group , Medical Laser Research Center, ACECR , Tehran , Iran.
b Photodynamic Research Group , Medical Laser Research Center, ACECR , Tehran , Iran.
J Biomol Struct Dyn. 2018 Jul;36(9):2216-2223. doi: 10.1080/07391102.2017.1345698. Epub 2017 Jul 6.
The interaction of methylene blue (MB) as a photosensitizer with graphene oxide nano-sheets (GO) was examined in aqueous solution using UV-vis spectrophotometric techniques. MB-GO composites were prepared by mixing the solutions of GO nano-sheets and methylene blue due to interacting of the cationic methylene blue photosensitizer via electrostatic and π-π stacking or hydrophobic cooperative interactions. The cell killing potential of nanocomposite was examined on the MDA-MB-231 breast cancer cells in the absence and presence of red LED irradiation. The results demonstrated that the MB-GO nanocomposite has good performance in photodynamic therapy (PDT) during red LED irradiation. The cytotoxicity of nanocomposite caused reducing cell viability up to 20%. These effects would be due to the nano size structure of composite that could lead to effective cellular penetration. Also the significant difference has seen in lower concentrations of MB and MB-GO nanocomposite. The results show more than 40% increases in cell killing potential in lower concentrations of nanocomposite by using 2.5 μg/mL of each compound. The ratio of GO/MB can affect the interaction and higher ratios of graphene oxide (GO/MB > 1) can induce dimerization of MB. In lower concentrations and ratios of (GO/MB < 1) the free MB concentration increases and the electron shuttling effect of GO in photo activity decreases - which could affect the photocatalytic yield in PDT. The cell viability measurements confirm these effects on cancer cell killing potential of nanocomposite. According to microscopic and PDT assay results, the nanocomposite distribution and diffusion in cells enhanced the photochemical reaction yield in photodynamic therapy of MDA-MB-231 breast cancer cell line.
采用紫外可见分光光度技术研究了亚甲蓝（MB）作为敏化剂与氧化石墨烯纳米片（GO）在水溶液中的相互作用。MB-GO 复合材料是通过混合 GO 纳米片和亚甲蓝的溶液制备的，这是由于阳离子亚甲蓝敏化剂通过静电和 π-π 堆积或疏水协同相互作用相互作用。在不存在和存在红色 LED 照射的情况下，在 MDA-MB-231 乳腺癌细胞上检查了纳米复合材料的细胞杀伤潜力。结果表明，MB-GO 纳米复合材料在红色 LED 照射下具有良好的光动力治疗（PDT）性能。纳米复合材料的细胞毒性导致细胞活力降低了 20％。这些作用可能是由于复合纳米材料的纳米尺寸结构能够导致有效的细胞穿透。此外，在较低浓度的 MB 和 MB-GO 纳米复合材料中也观察到明显的差异。结果表明，在较低浓度的纳米复合材料中，通过使用每种化合物的 2.5μg/mL，细胞杀伤潜力增加了 40％以上。GO/MB 的比例会影响相互作用，并且较高比例的氧化石墨烯（GO/MB> 1）会诱导 MB 的二聚化。在较低浓度和比例（GO/MB<1）下，游离 MB 浓度增加，GO 在光活性中的电子穿梭作用降低-这可能会影响 PDT 中的光催化产率。细胞活力测量结果证实了这些对纳米复合材料杀伤癌细胞潜力的影响。根据显微镜和 PDT 测定结果，纳米复合材料在细胞中的分布和扩散增强了 MDA-MB-231 乳腺癌细胞系光动力治疗的光化学反应产率。
