Xu Yongmei, Du Yumin
Department of Environmental Science, Wuhan University, Wuhan 430072, PR China.
Int J Pharm. 2003 Jan 2;250(1):215-26. doi: 10.1016/s0378-5173(02)00548-3.
Chitosan nanoparticles (CS NP) with various formations were produced based on ionic gelation process of tripolyphosphate (TPP) and chitosan. They were examined with diameter 20-200 nm and spherical shape using TEM. FTIR confirmed tripolyphosphoric groups of TPP linked with ammonium groups of chitosan in the nanoparticles. Factors affecting delivery properties of bovine serum albumin (BSA) as model protein have been tested, they included molecular weight (Mw) and deacetylation degree (DD) of chitosan, the concentration of chitosan and initial BSA, and the presence of polyethylene glycol (PEG) in encapsulation medium. Increasing Mws of chitosan from 10 to 210 kDa, BSA encapsulation efficiency was enhanced about two times, BSA total release in PBS (phosphate buffer saline) pH 7.4 in 8 days was reduced from 73.9 to 17.6%. Increasing DD from 75.5 to 92% promoted slightly the encapsulation efficiency and decelerated the release rate. The encapsulation efficiency was highly decreased by increase of initial BSA and chitosan concentration; higher loading capacity of BSA speeded the BSA release from the nanoparticles. Adding PEG hindered the BSA encapsulation and accelerated the release rate.
基于三聚磷酸钠（TPP）与壳聚糖的离子凝胶化过程制备了具有不同形态的壳聚糖纳米颗粒（CS NP）。使用透射电子显微镜（TEM）对其进行检测，结果显示颗粒直径为20 - 200 nm，呈球形。傅里叶变换红外光谱（FTIR）证实了纳米颗粒中TPP的三聚磷酸基团与壳聚糖的铵基团相连。对影响作为模型蛋白的牛血清白蛋白（BSA）递送特性的因素进行了测试，这些因素包括壳聚糖的分子量（Mw）和脱乙酰度（DD）、壳聚糖和初始BSA的浓度以及包封介质中聚乙二醇（PEG）的存在情况。壳聚糖的Mw从10 kDa增加到210 kDa时，BSA的包封效率提高了约两倍，在pH 7.4的磷酸盐缓冲盐水（PBS）中8天内BSA的总释放率从73.9%降至17.6%。DD从75.5%增加到92%时，略微提高了包封效率并减缓了释放速率。初始BSA和壳聚糖浓度的增加使包封效率大幅降低；BSA的较高负载量加快了其从纳米颗粒中的释放速度。添加PEG阻碍了BSA的包封并加快了释放速率。
