普鲁兰多糖的硬脂酸修饰及其作为纳米药物载体的研究

Preparation of Self-assembled Nanoparticles of Stearic Acid Modified Pullulan Derivatives and Their Application as Novel Carriers of Drug Delivery

利用1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)和4-二甲氨基吡啶(DMAP)催化硬脂酸(SA)与具有良好生物相容性的普鲁兰多糖(Pullulan)反应,将硬脂酸接枝在普鲁兰分子链的羟基上,得到取代度不同的疏水改性两亲性普鲁兰多糖衍生物PUSA1,PUSA2及PUSA3,其临界胶束浓度分别为50,32,18μg/mL;透射电镜(TEM)图像显示透析法制备的PUSA自组装颗粒为球形.以阿霉素为模型药物制备了PUSA载药纳米粒,考察了载药纳米粒的载药量、包封率和体外药物释放.结果表明PUSA3的包封率高达84%,载药量达7.79%.药物可在37℃,pH=7.4的PBS溶液中持续释放90 h以上.细胞毒性实验(MTT)结果显示当PUSA的浓度高达1000μg/mL时48 h后细胞存活率依然在90%左右.流式细胞及荧光分析表明载药纳米粒的细胞摄取率远远高于游离药物.说明PUSA是一种新型的有潜在应用价值的药物载体材料.

tearic acid modified biocompatible pullulan derivatives（PUSA1,PUSA2,PUSA3） with different degrees of substitution were synthesized via the reaction between the hydroxyl group of pullulan and carboxyl group of stearic acid（SA） in the presence of 1-（3-dimethylaminopropyl）-3-ethyl-carbodiimide hydrochloride（EDC） and 4-dimethylaminopyridine（DMAP）.The critical micelle concentration（CMC） were 50,32,18 μg/mL for PUSA1,PUSA2 and PUSA3 respectively,and transmission electron microscopy（TEM） images demonstrated that the self-assembled nanoparticles of PUSA made by dialysis method showed spherical shape.Doxorubicine（DOX）,as a model drug,was loaded into the self-assembled nanoparticles of PUSA,and the highest encapsulation efficiency（84%） and drug loading content（7.79%） were achieved in PUSA3.The release of DOX in nanoparticles in vitro at pH 7.4 demonstrated slow sustained release over 90 h,while in the acidic environment,showed faster release.The study of cell cytotoxicity in vitro showed PUSA self-aggregated nanoparticles had no cell cytotoxicity even at high concentration of PUSA（1000 μg/mL）.The uptake efficiency of PUSA/DOX,analyzed by flow cytometer and fluorescence,was rather higher than that of free DOX,which indicated that PUSA nanoparticles offer considerable potential as drug carriers for the efficient delivery of anti-cancer drugs.