中文摘要：

采用简单的溶液浇铸法制备了不同硒化镉-硫化锌核壳结构量子点（CdSe-ZnSQDs）含量的QDs/乳酸-乙醇酸共聚物（PLGA）纳米复合材料薄膜,对薄膜的微观结构、谱学性能等进行了系统的研究后,重点研究了PLGA、QDs/PLGA复合材料的体外降解行为.荧光光谱、紫外-可见光谱分析结果显示QDs与PLGA复合后仍具有稳定优异的发光性能和吸光度,且发光和吸光强度随QDs含量增加而增大.在体外降解的研究中,凝胶渗透色谱结果和磷酸盐缓冲液的pH值变化显示量子点的加入加快了PLGA的降解;而复合材料的荧光效应随着降解的进行而逐渐减弱.以上结果证明CdSe-ZnSQDs/PLGA纳米复合材料可采用简单的溶液浇铸法成功制备,且可通过检测荧光效应变化来监测QDs/PLGA复合材料的降解进程.

英文摘要：

PLGA / QDs nanocomposite films,containing different concentrations of Cd Se-Zn S quantum dots,were prepared via the method of solution casting. The objective of this research was to investigate the optical properties and in vitro degradation of poly（ lactide-co-glycolide） / Cd Se-Zn S quantum dots（ PLGA / QDs）nanocomposites. Photoluminescence spectra and ultraviolet-visible spectra explained that there was no effect on the luminescence property as well as the absorbance of light of QDs after being composited with PLGA,whose intensities increase with increasing the concentration of QDs in PLGA films. The results of gel permeation chromatography（ GPC） for PLGA and PLGA / QDs nanocomposites films showed that the weight-average molecular weight（ Mw） of unfilled PLGA and PLGA/QDs nanocomposites films decreased from 13300 to 3000 and from 13300 to 2400 respectively in three weeks,and their corresponding molecular weight distributions index decreased from 4. 10 to 2. 19 and from 4. 10 to 2. 21. The results of p H for phosphate-buffered saline（ PBS） revealed that the p H value firot lowered and then increased. Both the results of GPC and p H confirmed that the presence and uniform dispersion of QDs in the PLGA,to some extend,led to a faster degradation rate of the PLGA compared with unfilled PLGA. The PL intensity of PLGA / QDs nanocomposites films decreased along with the degradation process. Pores and wrinkles began to emerge on the surfaces of the films after degradation and increased gradually as the degradation time extended. The results suggest that the PLGA / QDs nanocomposites films can be prepared via the method of solution casting,and PLGA / QDs nanocomposites have potential applications for monitoring in vivo degradation of PLGA.