壳聚糖修饰的纳米羟基磷灰石基因结合性研究  

Chitosan modification and gene binding property of hydroxyapatite nanoparticles

作　　者：刘岩[1] 毛岳峰[1] 胡霞[1] 王国慧[1] 谭娟[1] 叶飞[1] 李鹏洲[1] 张大伟[1] 朱晒红[1] 

机构地区：[1]中南大学湘雅三医院医学实验中心,湖南长沙410013

出　　处：《中国现代医学杂志》2012年第20期18-23,共6页China Journal of Modern Medicine

基　　金：国家自然科学基金(No:81071869)

摘　　要：目的评估用壳聚糖修饰的纳米羟基磷灰石(HA)基因载体结合和保护DNA的性能。方法 HA纳米颗粒胶体液中加入壳聚糖弱酸溶液,以修饰HA纳米颗粒;透射电镜下观察壳聚糖修饰后HA纳米颗粒的形貌及粒径;在不同pH值环境下(5、6、7、8和9)测定修饰前后的HA纳米颗粒的Zeta电位;采用离心后测上清DNA浓度检测未修饰的HA纳米颗粒和经壳聚糖修饰后的HA纳米颗粒结合DNA的能力及壳聚糖-HA纳米颗粒与DNA解离的方式;应用DNA抗核酸酶保护实验测定修饰后的HA纳米颗粒保护DNA的能力。结果透射电镜观察经壳聚糖修饰的HA纳米颗粒周围有长梭状的壳聚糖颗粒包绕,粒径较均匀,约为50 nm,分散性较好;经过壳聚糖修饰的HA纳米颗粒较未修饰的HA纳米颗粒的Zeta电位显著升高(P<0.05)。血清、磷酸缓冲液(PBS)可以使结合到壳聚糖-HA纳米上的DNA解离。DNA结合及抗核酸酶保护实验显示,修饰后的HA纳米和DNA质量比达500∶1时,可更有效结合并保护DNA。结论经过壳聚糖修饰的HA基因载体分散性更好,Zeta电位显著提高,更有效地结合和保护DNA。[Objective] To evaluate the feasibility of surface modification on the DNA-binding of nano- hydroxyapatite （HA）. [Methods] Chemical co-precipitation-hydrothermal synthesis was utilized to prepare the HA particles, and chitosan was used for surface modification of the HA. The structure of the chitosan-modi- fled HA was observed by transmission electron microscopic （TEM）. At different pH values （5, 6, 7, 8, 9）, zeta potential detection of the HA were carried out before and after surface modification. The binding capacity of chitosan-modified HA and no-modified HA to DNA were tested by measuring DNA concentration in super- natant after centrifugation. The way of chitosan-modified HA/DNA dissociation were analyzed by agarose gel electrophoresis analysis. The capacity of protecting DNS by chitosan-modified HA was assayed by the experiment of DNA degradation. [Results] The diameter of HA and chitosan nanoparticles were about 50 nm under TEM observation, there were some chitosan particles around the HA particles, had good dispersion. The Zeta potential of HA nanoparticles with chitosan surface modification was increased compared with no-modified HA （P 〈0.05）. The absorbed DNA can be separated by serum and PBS. DNA binding test showed that chitosan- modified HA could completely bind DNA when the w/w ratio of chitosan-modified HA and DNA was more than 500 ： 1. It could effectively protect DNA against with HA nanoparticles, HA nanoparticles with chitosan being digested by DNase I. [Conclusion] Compared surface modification had better dispersion, higher Zeta potentials. It can serve as an effective vector for DNA binding and transfer.

关 键 词：羟基磷灰石 壳聚糖 分散稳定性 基因载体 

分 类 号：Q782[生物学—分子生物学]