聚乙二醇单甲醚接枝壳聚糖自组装纳米球的制备

Preparation of self-assembled monomethoxy poly(ethylene glycol) -grafted-chitosan nanoparticles

目的：合成聚乙二醇单甲醚接枝壳聚糖（monomethoxy poly（ethylene glycol）-grafted—chitosan，mPEG—g—CS），并制备自组装纳米球。方法：利用甲醛连接法将聚乙二醇单甲醚（monomethoxy poly（ethylene glycol），mPEG）接枝于壳聚糖（chitosan，CS）分子，得到聚乙二醇（poly（ethylene glycol），PEG）改性的壳聚糖衍生物，并通过傅立叶红外光谱仪（Fourier transform infrared spectroscopy，FT-1R），核磁共振仪（proton nuclear magnetic resonance，^1H—NMR）对产物进行结构表征；采用超声透析法制备自组装纳米球，并通过透射电镜（transmission electron microscopy，TEM），动态激光粒度分析仪（dynamic laser light scattering，DLLS）表征了纳米球的形态和粒径；以芘为荧光探针，通过荧光检测分析测定了mPEG—g—CS的临界胶束浓度（critical micellar concentration，CMC）。结果：通过FT—IR，^1H—NMR确证了接枝产物的存在；mPEG—g—CS在水溶液中能够自组装形成球状纳米胶束，平均粒径为250nm。结论：通过甲醛连接法制备mPEG—g—CS，具有制备方法简捷、反应周期短、易操作的优点。利用该产物制备的纳米球有望成为长循环纳米药物载体。

Objective ：To synthesize methoxy poly（ ethylene glycol）-grafted-chitosan and prepare its self-assembled nanoparticles. Methods ： The monomethoxy poly （ ethylene glycol） -grafted-chitosan was synthesized by formaldehyde linking method. The chemical structure of polymer was characterized by the fourier transform infrared spectroscopy（FT-IR） and proton nuclear magnetic resonance （^1H-NMR）. The self-assembled nanoparticles was prepared by probe sonication-dialysis method and analyzed by transmission electron microscopy （TEM）, dynamic laser light scattering （DLLS）. The critical micellar concentration（CMC） of monomethoxy poly（ethylene glycol）-grafted-chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. Results：The chemical structure of polymer was confirmed by FT-IR and ^1H-NMR. The self-assembled nanoparticles were spherical and their average diameter was about 250 nm. Conclusion：The preparation procedure of monomethoxy poly（ethylene glycol）-grafted-chitosan was easy to be operated. This novel nanoparticle system was promising to be a good long-circulating drug carrier.