Luo Xiaojun, Liu Xiaoyan, Pei Yinuo, Ling Yawen, Wu Ping, Cai Chenxin
Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, National and Local Joint Engineering Research Center of Biomedical Functional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, P. R. China.
J Mater Chem B. 2017 Oct 21;5(39):7949-7962. doi: 10.1039/c7tb02204b. Epub 2017 Sep 27.
A bifunctional gold-coated polypyrrole (PPy-Au) nanostructure with Raman and photothermal activity was developed, in which polypyrrole spheres (PPy NSs) were used as the core and coated with small Au NPs to form polypyrrole-Au (PPy-Au) nanostructures. As a result of the contribution from the coated Au nanoparticles (Au NPs), coupling occurred between the Au NPs and the PPy NSs, leading to an enhanced pyrrole Raman signal. PPy-Au nanostructures were thus used as Raman tags without requiring additional Raman dyes labeling and leaking the cargo dyes even in the absence of a complicated encapsulation process. When conjugated with aptamer S2.2, the nanostructures could specifically bind with the membrane protein MUC1, a kind of tumor-related biomarker that is overexpressed on the surface of human breast cancer cells (MCF-7). The specific detection of MCF-7 cells was thus achieved based on the pyrrole Raman signal. Moreover, the capacity of the PPy-Au nanostructures for transforming NIR light into heat was also greatly enhanced because of the coupling between the Au NPs and the PPy NSs, as indicated by the efficiency of the photothermal conversion up to 70.0% compared to 44.7% for the pure PPy NSs. Photothermal experiments proved that MCF-7 cells incubated with the nanostructures nearly died under 808 nm irradiation (0.5 W cm) for 20 min, and the tumors bearing on the mice were also effectively inhibited after the PTT.
开发了一种具有拉曼和光热活性的双功能金包覆聚吡咯（PPy-Au）纳米结构，其中聚吡咯球（PPy NSs）作为核心，并包覆有小金纳米颗粒（Au NPs）以形成聚吡咯-金（PPy-Au）纳米结构。由于包覆的金纳米颗粒（Au NPs）的作用，Au NPs与PPy NSs之间发生耦合，导致吡咯拉曼信号增强。因此，PPy-Au纳米结构被用作拉曼标签，无需额外的拉曼染料标记，即使在没有复杂封装过程的情况下也不会泄漏负载染料。当与适体S2.2缀合时，纳米结构可以与膜蛋白MUC1特异性结合，MUC1是一种在人乳腺癌细胞（MCF-7）表面过度表达的肿瘤相关生物标志物。因此，基于吡咯拉曼信号实现了对MCF-7细胞的特异性检测。此外，由于Au NPs与PPy NSs之间的耦合，PPy-Au纳米结构将近红外光转化为热的能力也大大增强，光热转换效率高达70.0%，而纯PPy NSs的光热转换效率为44.7%。光热实验证明，与纳米结构孵育的MCF-7细胞在808 nm照射（0.5 W/cm）下20分钟后几乎死亡，并且在光热治疗后小鼠体内的肿瘤也得到了有效抑制。
