纳米金-聚乙烯亚胺基因载体的制备

Preparation Gold-PEI Nanoparticles for Gene Delivery

目的:基因方法治疗癌症近年来取得了很大的突破,因此基因载体的构建显得尤为重要。其中纳米基因载体合成简单,成本低廉,并能够包裹、浓缩、保护核苷酸使其免受核酸酶降解,因此纳米材料广泛地应用于基因输送。我们拟开展聚乙烯亚胺-纳米金基因载体的制备及其表征。方法:采用层层包裹技术制备基因载体,首先通过柠檬酸钠还原法制备纳米金颗粒后,应用11-巯基十一烷酸对金颗粒进行修饰,使其表面带有羧基,然后进一步将带有氨基的低分子量聚乙烯亚胺与羧基进行连接。应用动态光散射(DLS),紫外可见光谱(UV)和透射电子显微镜(TEM)对构建的纳米基因载体进行表征。结果:成功制备了聚乙烯亚胺-纳米金基因载体,检测表明每一步制备出的产物纳米尺寸在20-30 nm之间,液体均匀稳定,分散系数(PDI)在0.2以下,Zeta电位测定表明,每步的产物电荷变化与外层包裹的反应物有关。尽管金颗粒外层包裹聚乙烯亚胺,但是总体上纳米载体尺寸没有发生太大的变化,TEM检测表明每一步形成了均匀的、单分散的、球状的纳米颗粒。结论:我们通过层层包裹技术成功制备了聚乙烯亚胺-纳米金基因载体,在进一步开展的生物活性的检测中,希望通过纳米载体的携带作用,将基因转染进靶细胞,从而检测相关基因对靶细胞的沉默作用,提高基因药物的应用,为开发新型基因药物提供基础。

Objective： In recent years, gene delivery system has made great breakthrough in cancer therapy, therefore it is important to fabricate efficient gene cartier. Among them, nanomaterials which can entrap and concentrate nucleic acid thereby avoiding degradation by nuclease have been extensively used in gene delivery due to their easy preparation and low cost. Herein, we prepared and characterized gold-polyethyleneimine （Gold-PEI） nanopaticles for gene delivery. Methods： We demonstrated a layer-by-layer method to prepare gold-PEI gene carrier. Gold nanoparticles were prepared by citrate reduction and then 11-mercaptoundecanoic acid （MUA） was to be deposited on the gold surface to facilitate the binding of the subsequent layers followed by the addition of PEI to prepare Gold-PEI nanoparticles. The naoparticles in each procedure was characterized by dynamic lighting scatter （DLS）, UV-vis spectra and transmission electron microscopy （TEM）, respectively. Results： We successfully fabricated Gold-PEI nanoparticles for gene carrier. It was shown that the product size in each procedure was about 20-30 nm and their polydispersity （PD!） was below 0.2, indicating the solution of products was distributed uniformly. Additionally, a change of the zeta-potential after completion of each layer signified the deposition of each reactant. As a whole, the size of gold-PEI had no obvious increase compared with that of gold nanoparticles. Our results suggested that the morphologies of gold, gold-MUA and gold-PEI nanoparticles were approximately spherical shape as measured by TEM. Conclusion： We manufactured gold-PEI nanopartieles for gene delivery by layer-by-layer approach. The gold-PEI nanoparticles was expected to be a promising gene carrier allowing for increasing its silence effect in targeted cells and improving gene-regnlated efficiency.