MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, People's Republic of China.
Nanoscale Res Lett. 2014 Feb 18;9(1):86. doi: 10.1186/1556-276X-9-86.
A facile and green strategy is reported for the fabrication of nanosized and reduced covalently PEGylated graphene oxide (nrGO-PEG) with great biocompatibility and high near-infrared (NIR) absorbance. Covalently PEGylated nGO (nGO-PEG) was synthesized by the reaction of nGO-COOH and methoxypolyethylene glycol amine (mPEG-NH2). The neutral and purified nGO-PEG solution was then directly bathed in water at 90°C for 24 h without any additive to obtain nrGO-PEG. Covalent PEGylation not only prevented the aggregation of nGO but also dramatically promoted the reduction extent of nGO during this reduction process. The resulting single-layered nrGO-PEG sheets were approximately 50 nm in average lateral dimension and exhibited great biocompatibility and approximately 7.6-fold increment in NIR absorption. Moreover, this facile reduction process repaired the aromatic structure of GO. CCK-8 and flow cytometry (FCM) assays showed that exposure of A549 cells to 100 μg/mL of nrGO-PEG for 2 h, exhibiting 71.5% of uptake ratio, did not induce significant cytotoxicity. However, after irradiation with 808 nm laser (0.6 W/cm2) for 5 min, the cells incubated with 6 μg/mL of nrGO-PEG solution showed approximately 90% decrease of cell viability, demonstrating the high-efficiency photothermal therapy of nrGO-PEG to tumor cells in vitro. This work established nrGO-PEG as a promising photothermal agent due to its small size, great biocompatibility, high photothermal efficiency, and low cost.
本文报道了一种简便、绿色的策略，用于制备具有良好生物相容性和高近红外（NIR）吸收的纳米级和还原的共价 PEG 化氧化石墨烯（nrGO-PEG）。通过 nGO-COOH 和甲氧基聚乙二醇胺（mPEG-NH2）的反应合成共价 PEG 化 nGO（nGO-PEG）。然后，将中性和纯化的 nGO-PEG 溶液直接在 90°C 的水中浸泡 24 小时，无需任何添加剂即可获得 nrGO-PEG。共价 PEG 化不仅防止了 nGO 的聚集，而且在还原过程中极大地促进了 nGO 的还原程度。所得的单层 nrGO-PEG 片的平均横向尺寸约为 50nm，具有很好的生物相容性和近红外吸收约 7.6 倍的增加。此外，这种简便的还原过程修复了 GO 的芳香结构。CCK-8 和流式细胞术（FCM）检测表明，A549 细胞暴露于 100μg/mL 的 nrGO-PEG 2 小时，摄取率为 71.5%，不会引起明显的细胞毒性。然而，在用 808nm 激光（0.6W/cm2）照射 5 分钟后，孵育 6μg/mL nrGO-PEG 溶液的细胞活力下降约 90%，表明 nrGO-PEG 对体外肿瘤细胞具有高效的光热治疗作用。这项工作确立了 nrGO-PEG 作为一种有前途的光热剂，因为它具有尺寸小、生物相容性好、光热效率高和成本低的特点。
