壳聚糖的分子参数对载药壳聚糖纳米粒体外性质的影响研究

 目的研究不同脱乙酰度及不同相对分子质量的壳聚糖(CS)对壳聚糖纳米粒体外性质的影响,为载药壳聚糖纳米粒的处方优化提供实验依据。方法以去甲斑蝥素(NCD)为模型药物,以不同脱乙酰度、不同相对分子质量壳聚糖为主要膜材,采用离子交联法制备壳聚糖纳米粒(CS-NP),考察纳米粒的形态、粒径、Zeta电位、药物包封率、载药量及体外释放特征。结果该方法制备的CS-NP外观呈圆形,粒径均匀。随着CS的脱乙酰度的降低,纳米粒粒径增大,Zeta电位降低,药物包封率及载药量均下降,且体外释药速度加快;随着CS的相对分子质量降低,纳米粒粒径变小,Zeta电位、药物包封率及载药量无明显变化, 但体外释药速度增加。结论CS的脱乙酰度、相对分子质量对纳米粒的体外性质有较大的影响,可通过选用不同脱乙酰度或相对分子质量的CS,制备得到不同粒径的壳聚糖纳米粒,并达到调节药物释放速度的目的。

Study on effect of molecular parameters of chitosan on properties of chitosan nanoparticles in vitro

OBJECTIVE To investigate the effect of deacetylation degree (DD) and molecular weight (Mr) of chitosan (CS) on the properties of CS nanoparticles (CS-NP) in vitro in order to optimize the formulation of CS-NP. METHODS CS-NP was prepared by ionic crosslinkage process using different chitosan with various DD and Mr, and norcanthardin (NCD) was used as a model drug. The properties of CS-NP, such as the appearance, average size, Zeta potential, encapsulation efficiency (EE), loading capacity (LC) and the drug release rate in vitro, were detected,respectively. RESULTS All CS-NP were spherical with narrow size distribution. With the decrease of DD of CS, the average size of CS-NP was increased while the Zeta potential, the EE and LC of NCD were all decreased. With the decrease of Mr of CS, the average size of the CS-NP was reduced correspondingly while the zeta potential, the EE and LC were not changed significantly. Both decrease of DD and MW of CS rendered the speed-up of the release rate of NCD from the CS-NP in vitro. . CONCLUSION Both DD and Mr of CS no-lablely affected on the properties of the CS-NP in vitro. By the adjustment of the two molecular parameters, CS-NP with various average size and drug release rate could be obtained.