银杏：一种用于合成细胞相容性石墨烯的天然还原剂。

BACKGROUND: Graphene is a novel two-dimensional planar nanocomposite material consisting of rings of carbon atoms with a hexagonal lattice structure. Graphene exhibits unique physical, chemical, mechanical, electrical, elasticity, and cytocompatible properties that lead to many potential biomedical applications. Nevertheless, the water-insoluble property of graphene restricts its application in various aspects of biomedical fields. Therefore, the objective of this work was to find a novel biological approach for an efficient method to synthesize water-soluble and cytocompatible graphene using Ginkgo biloba extract (GbE) as a reducing and stabilizing agent. In addition, we investigated the biocompatibility effects of graphene in MDA-MB-231 human breast cancer cells. MATERIALS AND METHODS: Synthesized graphene oxide (GO) and GbE-reduced GO (Gb-rGO) were characterized using various sequences of techniques: ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. Biocompatibility of GO and Gb-rGO was assessed in human breast cancer cells using a series of assays, including cell viability, apoptosis, and alkaline phosphatase (ALP) activity. RESULTS: The successful synthesis of graphene was confirmed by UV-vis spectroscopy and FTIR. DLS analysis was performed to determine the average size of GO and Gb-rGO. X-ray diffraction studies confirmed the crystalline nature of graphene. SEM was used to investigate the surface morphologies of GO and Gb-rGO. AFM was employed to investigate the morphologies of prepared graphene and the height profile of GO and Gb-rGO. The formation of defects in Gb-rGO was confirmed by Raman spectroscopy. The biocompatibility of the prepared GO and Gb-rGO was investigated using a water-soluble tetrazolium 8 assay on human breast cancer cells. GO exhibited a dose-dependent toxicity, whereas Gb-rGO-treated cells showed significant biocompatibility and increased ALP activity compared to GO. CONCLUSION: In this work, a nontoxic natural reducing agent of GbE was used to prepare soluble graphene. The as-prepared Gb-rGO showed significant biocompatibility with human cancer cells. This simple, cost-effective, and green procedure offers an alternative route for large-scale production of rGO, and could be used for various biomedical applications, such as tissue engineering, drug delivery, biosensing, and molecular imaging.

背景：石墨烯是一种新型二维平面纳米复合材料，由具有六边形晶格结构的碳原子环组成。石墨烯具有独特的物理、化学、机械、电气、弹性和细胞相容性特性，这导致了其在许多潜在的生物医学应用中的应用。然而，石墨烯的不溶性限制了其在生物医学领域各个方面的应用。因此，本工作的目的是寻找一种新的生物方法，以高效地合成水溶性和细胞相容性的石墨烯，使用银杏叶提取物（GbE）作为还原剂和稳定剂。此外，我们研究了石墨烯在 MDA-MB-231 人乳腺癌细胞中的生物相容性效应。

材料和方法：使用各种技术序列对合成的氧化石墨烯（GO）和银杏叶提取物还原的氧化石墨烯（Gb-rGO）进行了表征：紫外-可见（UV-vis）光谱、傅里叶变换红外光谱（FTIR）、动态光散射（DLS）、扫描电子显微镜（SEM）、原子力显微镜（AFM）和拉曼光谱。通过一系列实验，包括细胞活力、细胞凋亡和碱性磷酸酶（ALP）活性，评估了 GO 和 Gb-rGO 在人乳腺癌细胞中的生物相容性。

结果：通过 UV-vis 光谱和 FTIR 确认了石墨烯的成功合成。DLS 分析用于确定 GO 和 Gb-rGO 的平均粒径。X 射线衍射研究证实了石墨烯的结晶性质。SEM 用于研究 GO 和 Gb-rGO 的表面形貌。AFM 用于研究制备的石墨烯的形貌以及 GO 和 Gb-rGO 的高度轮廓。拉曼光谱证实了 Gb-rGO 中缺陷的形成。通过水溶性四唑 8 测定法在人乳腺癌细胞上研究了制备的 GO 和 Gb-rGO 的生物相容性。GO 表现出剂量依赖性毒性，而 Gb-rGO 处理的细胞表现出与 GO 相比显著的生物相容性和增加的 ALP 活性。

结论：在这项工作中，使用银杏叶提取物（GbE）作为无毒的天然还原剂来制备可溶性石墨烯。所制备的 Gb-rGO 与人癌细胞具有显著的生物相容性。这种简单、经济高效且环保的方法为 rGO 的大规模生产提供了一种替代途径，并可用于各种生物医学应用，如组织工程、药物输送、生物传感和分子成像。