甲壳三糖-g-壳聚糖/累托石纳米复合材料作为基因载体的研究

本文合成了甲壳三糖-g-壳聚糖（TCS），并与累托石插层复合制备纳米复合材料，采用XRD和TEM对其进行了表征。粒径分析结果表明，两种分子量的TCS与pDNA复合物的粒径大小都在75nm左右，而累托石加入后，其粒径都不同程度的增加，最大达到191nm。在PBS中的聚集动力学及琼脂糖凝胶电泳实验发现，高分子量TCS /pDNA复合物较低分子量复合物稳定，而累托石的加入降低了其稳定性。体外转染实验初步表明，甲壳三糖-g-壳聚糖/累托石-DNA复合物能介入肝癌细胞中并表达荧光。该纳米复合材料可作为潜在的非病毒基因载体。

Study of trisaccharide-g-chitosan/rectorite nanocomposites as gene carrier

Trisaccharide-g-chitosan was prepared and intercalated into rectorite to obtain the nanocomposites, and their gene transfection study was evaluated. The results revealed that trisaccharide-g-chitosan have inserted into silicate layers to form the intercalated nanocomposites and rectorite dispersed well into polymer matrix. The sizes of two different-molecular-weight trisaccharide-g-chitosan/pDNA complexes were about 75nm, but the size increased after the addition of rectorite, the largest size reached 191nm. The aggregation kinetics of the polyplexes (chitosan with pDNA) found that high-molecular-weight trisaccharide-g-chitosan/pDNA complex was very stable; the size did not change in 1h. The incorporation of rectorite had a negative effect on the stability of the complexes. The gel electrophoresis analysis indicated that the complexes based on high-molecular- weight trisaccharide-g-chitosan and its nanocomposites began to release DNA only at a relatively low N/P ratio (the molar ratio between all protonable amino groups of chitosan and the phosphate groups of DNA) of 1, while the low-molecular-weight chitosan/DNA and its nanocomposites complexes released DNA from the much higher N/P ratio, even 60:1. The transfection study showed that trisaccharide-g-chitosan/pDNA complex can enter into the cell and the prominent GFP expression was observed. All the results suggest that trisaccharide-g-chitosan /rectorite nanocomposite may be a potential non-viral gene carrier.