敏感性聚电解质纳米粒子的制备及对5-FU的控制释放

摘要

以壳聚糖( CS)和海藻酸钠( SA)为原料，通过接枝共聚制备了壳聚糖接枝聚N-乙烯基吡烙烷酮( CS-g-PVP)和海藻酸钠接枝聚N-乙烯基吡烙烷酮(SA-g-PVP)，然后利用静电自组装得到了pH敏感性聚电解质纳米粒子，研究了纳米粒子对5-氟尿嘧啶的负载及释放性能的影响。傅立叶红外光谱验证了聚合物的结构。当CS-g-PVP与SA-g-PVP体积比为3∶7时，形成的纳米粒子结构最稳定。透射电镜表明纳米粒子具有较规则的球形结构，尺寸在30~50 nm左右。聚电解质纳米粒子对5-FU表现出较高的负载能力，环境pH值和离子强度等因素对5-FU的释放有影响。%pH-sensitive polyelectrolyte complex nanoparticles assembled from chitosan-graft-poly ( 1-vinyl-2-pyrrolidone) (CS-g-PVP) and sodium alginate-graft-poly(1-vinyl-2-pyrrolidone) (SA-g-PVP) were prepared for entrapment and release of 5-fluorouracil ( 5-FU ) . The structure of polymers was determined by fourier-transformed infrared spectroscopy ( FTIR) . The highly aggregated nanoparticle was formed at the weight ratio of CS-g-PVP and SA-g-PVP is 3∶7 with a core formed from positively charged CS and negatively charged SA and a shell formed from hydrophilic PVP. The size and morphology of the nanoparticles was observed by transmis-sion electron microscopy ( TEM) . The dried particles gave the normally spheres with an average diameter of 30~50 nm. The CS-g-PVP/SA-g-PVP polyelectrolyte complex nanoparticles exhibited high drug loading content and encapsulation efficiency for 5-FU. Decreasing pH to weak acid or increasing ionic strength of nanoparticles solution,a sustained and controlled drug release was observed due to the deformation of nanoparticles.