羧甲基壳聚糖纳米胶束的制备与光响应性研究

智能响应性聚合物胶束作为药物控释传递系统的载体引起广泛关注，其中光刺激因为可控性高、清洁高效等优点被广泛研究.该文以丁二酸酐为连接臂将1-芘甲醇(PyM)接枝到羧甲基壳聚糖(CMCS)的氨基上制得两亲性大分子(PMS-g-CMCS)，然后在水溶液中自组装成光响应纳米胶束.采用动态光散射(DLS)和透射电镜(TEM)表征胶束的大小和形态，并研究光刺激前后胶束的大小变化；通过核磁和荧光研究胶束的光响应机制.结果表明该胶束为类球形核-壳结构，粒径约200 nm，且具有较好储存稳定性；在紫外(UV)光照下，能发生结构改变，其光响应机制可归因于连接PyM的酯键断裂.胶束显示出可用作疏水性药物或农药光控释放载体的潜力.

Preparation and study of photo-responsive nanomicelles based on carboxymethyl chitosan

The intelligent response polymer micelles have attracted much attention as a carrier of drug controlled release system. Light stimulation is of great interest because of its advantages such as high controllability， clean and high efficiency. In this thesis， 1-pyrenemethyl succinate (PMS) was prepared by the esterification of 1-pyrenemethanol with succinic anhydride， which was grafted onto the carboxymethyl chitosan backbone to obtain photoresponsive polymer (PMS-g-CMCS)， which could self-assemble into light-responsive polymeric micelles in aqueous condition. The size and morphology of the micelles were characterized and their changes before and after light stimulation were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Their photoresponsive mechanism was also investigated by fluorescence and 1H NMR. The results showed that the micelles are spherical-core structures with a diameter of about 200 nm and exhibiteded good storage stability. Under the UV light stimulus， the structure will be able to chang. The photoresponsive mechanism can be attributed to the breakage of ester bond linked to PyM. These properties of micelles show the potential for use as a light controlled release carrier of hydrophobic drug or pesticide.