| 刘庆 王霁宁 李静 黄赛燕 沈园园.巯基化壳聚糖季铵盐用于基因输送的研究[J].,2016,16(33):6414-6417 |
| 巯基化壳聚糖季铵盐用于基因输送的研究 |
| Thiolated Trimethylated Chitosan for Efficient Gene Delivery |
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| DOI： |
| 中文关键词: 基因输送 壳聚糖季铵盐 还原响应性 |
| 英文关键词: Gene delivery Trimethylated chitosan Reductive response |
| 基金项目:国家自然科学基金项目（81173015） |
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| 中文摘要: |
| 目的：本研究诣在对壳聚糖进行修饰，以解决其水溶性问题和基因释放困难的问题。方法：本研究通过2,3-环氧丙基三甲基
氯化铵和N- 乙酰-L- 半胱氨酸对壳聚糖进行修饰，得到巯基化壳聚糖季铵盐（TMC-SH），使其在生理条件下带正电并含有一定
量的游离巯基。以TMC-SH 为基因载体，形成基因复合物。通过琼脂糖凝胶电泳考察其稳定性，并测定其粒径和灼-电位。通过DTT
条件下的粒径测定，考察基因复合物的还原响应性。结果：核磁结果表明合成TMC-SH 的季铵盐取代度为22 %，游离巯基-SH 含
量为79.22 滋mol/g；琼脂糖凝胶电泳结果表明以TMC-SH 为载体形成的二硫键交联的基因复合物TMC-SS/pDNA具有较好的稳
定性；而且，二硫键交联以后基因复合物粒径较小，结构更为密实；在还原条件下粒径变大，表明二硫键交联的基因复合物变得疏
松，说明其粒径具有还原响应性。结论：对壳聚糖进行低取代度的季铵盐修饰和一定量的巯基化修饰后，其具有较好的包载pDNA
能力和还原响应性的基因释放能力。 |
| 英文摘要: |
| Objective:Chitosan has been widely used as gene carrier, as it is biocompatible and biodegradable. We develop a solution
here, to solve the problem of chitosan's solubility at neutral pH and gene release in cytosol at the same time.Methods:Thiolated
trimethylated chitosan (TMC-SH) was synthesized through trimethylation of chitosan and subsequent thiolation of TMC. Then complexes
of TMC-SS/pDNA were formed through initially electrostatic interaction between positively-charged TMC-SH and negatively-charged
pDNA and the following cross-linking due to the formation of disulfide bonds. The complexes were characterized in terms of size,-potential,
agarose gel electrophoresis, size change in reductive environment.Results:It was determined that 22 % glucose units in TMC
were trimethylated according to 1H NMR data and Ellman's reagent assay showed that there was about 79.22 umol/g free thiol groups in
TMC-SH. Agarose gel electrophoresis assay showed that complexes of TMC-SS/pDNA was more stable than TMC/pDNA which could
be ascribed to oxidation of thiol groups into disulfide bonds generating cross-linked complexes. And the size of complexes
TMC-SS/pDNA was about 170 nm which was obviously smaller than TMC/pDNA with the size of about 220 nm. After incubated with
DTT, the complexes of TMC-SS/pDNA became looser with size of about 320 nm.Conclusion:After modification of chitosan, the product
TMC-SH is with low trimethylated substitution and with free thoil. The complexes of TMC-SS/pDNA possess good stability and redox-
responsive gene release. |
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