基于石墨烯量子点和金纳米棒的癌细胞金属增强荧光标记和热疗-化疗研究

Graphene quantum dots (GQDs) have shown great potential in biomedical applications owing to its tunable photoluminescence properties and biocompatible nature. However, the quantum yield of GQDs is relatively low in most reports, which hinder their applications on biological system. In this project, metal enhanced fluorescence of GQDs will be investigated by using gold nanorods (AuNRs) as metal core. Mesoporous silica is utilized as a spacer layer between AuNRs and GQDs. The fluorescence of GQDs can be enhanced by optimizing the thickness of the spacer layer. Depend on drug loading capacity of mesoporous silica and GQDs, and the photothermal effect of AuNRs, a multi-functional nano-carrier for targeted cancer cell imaging and chemo-phototherapy will be prepared. The nano-carrier can not only accurately transport the drug to the diseased site, but also is capable of releasing the drug by the near-infrared light irradiation and ablating the cancer cell, which can significantly improved the therapeutic efficacy of cancer treatment. The study will help to solve the shortcomings of traditional cancer treatments, and establish a integrated system which combine the cancer cell imaging, diagnosis, and treatment, which will provide new idea for anti-cancer study.

由于波长可调的光致发光特性和优异的生物相容性，石墨烯量子点在生物医学领域展现出巨大的应用潜力。然而，目前报道的大部分石墨烯量子点的量子产率仍然较低，限制了其在生物体系中的应用。本项目中，我们将深入研究金纳米棒对于石墨烯量子点的金属荧光增强作用。使用介孔二氧化硅作为金纳米棒和石墨烯之间的间隔层，通过优化间隔层的厚度，达到提高石墨烯量子点荧光强度的目的。利用介孔二氧化硅和石墨烯量子点对于抗癌药物多柔比星的负载能力和金纳米棒的光热效应，构建出可以同时应用到癌细胞靶向荧光成像和热疗-化疗联合治疗中的多功能纳米药物载体。该载体不但能够将药物准确地输运到病变部位，还能够在近红外光的照射下释放药物，并针对性的加热病变部位，从而增强抗癌效果。该研究将有助于解决传统癌症治疗方法的缺点，建立肿瘤成像、诊断、治疗为一体的综合体系，为抗癌研究提供新思路。

恶性肿瘤是困扰人类健康的重大疾病，开发出高灵敏度的癌症诊断技术和能够选择性杀灭肿瘤细胞的综合治疗手段，是减轻患者病痛并最终战胜癌症的关键。本项目主要目标是利用纳米材料的特殊光学性质，实现肿瘤细胞的荧光标记和光热治疗，并在此基础上构建肿瘤诊断、热疗、化疗为一体的多功能纳米载体。本项目研究内容主要包括以下几个方面：1.金纳米棒与介孔二氧化硅复合材料的制备及形貌调控；2.石墨烯（碳）量子点、氮化碳量子点、氧化钨量子点的制备及荧光性能测定；3.金纳米棒对荧光量子点的等离子共振荧光增强效应研究；4.还原氧化石墨烯-硫化铜复合材料、氧化钼纳米颗粒的可控制备及其癌细胞热消融效应测定。通过以上研究内容的实施，我们成功建立了金纳米棒与介孔二氧化硅复合材料的制备方法，对金纳米棒对荧光量子点的等离子共振荧光增强效应进行了初步的探索；建立了制备荧光量子点的溶剂热碱插层法和双氧水热解法；制备了具有较高光热转化效率的还原氧化石墨烯-硫化铜复合材料和氧化钼纳米颗粒，并成功应用于癌细胞热消融。以上重要结果的取得，为进一步构建诊疗一体的多功能纳米药物载体提供了研究基础。