载基因壳聚糖纳米粒的制备及其相关性质的初步研究

目的制备壳聚糖载基因纳米粒，并对其体外相关性质进行初步研究。方法采用复凝聚法制备载基因纳米粒；用纳米粒度仪测量粒度分布、多分散性和Zeta电位；用透射电镜观察粒子的形态；用荧光分光光度法和比色法测定包封率和载药量，并对主要影响因素进行考察；用凝胶阻滞分析和电性结合分析对载药方式进行初步推测。结果所制备的载基因纳米粒形态规则，大多呈球形，平均粒径约150nm，PDI＜0．2，Zeta电位约20mV；包封率大于90％，载药量约30％；凝胶阻滞和电性结合分析结果表明，pDNA与壳聚糖分子间可通过电性结合作用而完全结合。结论采用复凝聚法可制备粒度分布均匀，形态规则，具有较高包封率和载药量的载基因壳聚糖纳米粒；电性结合作用是载基因壳聚糖纳米粒载药的主要方式。

Preparation and characteristics of chitosan nanoparticles carrying gene in vitro

OBJECTIVE To prepare chitosan nanoparticles(CS-NP) carrying gene and study its characteristics in vitro. METHODS The chitosan nanoparticles carrying gene were prepared by complex coacervation. Its size distribution,polydispersity and Zeta potential were determined by nanoparticle size analyzer; The morphology was observed by transmission electronic micrograph.The encapsulating rate and loading efficiency were determined by fluorospectrophotometry and colorimetry .The manner of drug loading was speculated by Gel retardation assay and electronic-combination analysis. RESULTS The morphology of CS-NP was mostly spherical and well-distributed. The mean diameter was about 150 nm with polydispersity less than 0.2 and its Zeta potential was about 20 mV.The encapsulating rate was more than 90% and the loading efficiency was approximately 30%. The results of gel retardation and electronic-combination analysis showed chitosan could completely combine the pDNA by electronic combination.CONCLUSION The CS-NP with well-distributed spherical morphology,high encapsulating rate and loading efficiency can be prepared by complex coacervation. Electronic-combination is the main manner for CS-NP to carry gene.