两亲性壳聚糖基聚合物碳点的合成及其在载药方面的应用

通过水热法合成了系列具有高荧光量子产率（42.9%）辛基化壳聚糖基两亲性聚合物碳点荧光材料。利用红外光谱、紫外吸收光谱、光电子能谱、透射电镜、X射线衍射及荧光光谱对聚合物碳点进行了表征。以阿霉素为模型药物，研究了聚合物碳点对阿霉素的载药性能。当辛基取代度为76.42%时，其最大载药量和包封率分别为49.6%与47.4%。在磷酸盐缓冲液中，载药纳米胶束呈前期快速释放，后期缓慢释放的双相特征。将载药纳米胶束与鼻咽癌细胞作用，发现其存活率随着载药纳米胶束加入量的增加而降低，说明该纳米胶束对鼻咽癌细胞有一定的抑制作用。总之，该聚合物碳点材料在药物载体与荧光示踪方面有潜在的应用价值。

Synthesis of Amphiphilic Polymer Carbon Dots Fluorescence Materials from Octyl Chitosan and Their Applications in Drug Delivery

Fluorescent materials P(CS-g-OC-CA)Ds with high fluorescence quantum yield(42.9%) were prepared by hydrothermal method using chitosan, citric acid, Octylaldehyde and N-(2-hydroxyethyl) ethylenediamine as raw materials. The P(CS-g-OC-CA)Ds were characterized by infrared spectroscopy, ultraviolet spectroscopy (UV), X-ray powder diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and photoluminescence spectra. The drug loading properties of the P(CS-g-OC-CA)Ds were studied using doxorubicin (DOX) as a model drug. When the degree of octane substitution is 76.42%, the optimal loading and entrapment efficiency of DOX are 49.6% and 47.4%, respectively. Notably, the amount and encapsulation efficiency of DOX can be controlled by controlling the degree of octane substitution. After loading, the micelles are approximately 80-90 nm in diameter. The fluid mechanics particle size is 114.3 nm, and the surface potential is +5.72 mV. In vitro release studies demonstrate a dual release phase from the drug-loaded micelles in pH 7.4 phosphate buffer, with a rapid first-phase release and a slow second-phase release of DOX. Cytotoxicity studies demonstrate that there is no obvious cytotoxicity of blank P(CS-g-OC-CA)Ds, and the survival rate of nasopharyngeal carcinoma (CNE-2) cells decreases with the increasing of the amount of drug-loaded micelles. These results show that the nanomicelles have a strong inhibitory effect on CNE-2 cells. In conclusion, the obtained P(CS-g-OC-CA)Ds are potentially useful as drug-delivery and fluorescence trace systems.