Shi Xiao-Wen, Du Yu-Min, Sun Li-Ping, Yang Jian-Hong, Wang Xiao-Hui, Su Xue-Li
Department of Environmental Science, College of Resource and Environmental Science, Wuhan University, Wuhan 430072, China.
Macromol Biosci. 2005 Sep 16;5(9):881-9. doi: 10.1002/mabi.200500063.
Complex beads composed of alginate and carboxymethyl chitin (CMCT) were prepared by dropping aqueous alginate-CMCT into an iron(III) solution. The structure and morphology of the beads were characterized by IR spectroscopy and scanning electron microscopy (SEM). IR confirmed electrostatic interactions between iron(III) and the carboxyl groups of alginate as well as CMCT, and the binding model was suggested as a three-dimensional structure. SEM revealed that CMCT had a porous morphology while alginate and their complex beads had a core-layer structure. The swelling behavior, encapsulation efficiency, and release behavior of bovine serum albumin (BSA) from the beads at different pHs were investigated. The BSA encapsulation efficiency was fairly high (>90%). It was found that CMCT disintegrated at pH 1.2 and alginate eroded at pH 7.4 while the complex beads could effectively retain BSA in acid (>85%) and reduce the BSA release at pH 7.4. The results suggested that the iron(III)-alginate-CMCT bead could be a suitable polymeric carrier for site-specific protein drug delivery in the intestine.
通过将海藻酸钠 - 羧甲基壳聚糖（CMCT）水溶液滴入铁（III）溶液中来制备由海藻酸钠和羧甲基壳聚糖组成的复合珠。通过红外光谱和扫描电子显微镜（SEM）对珠的结构和形态进行了表征。红外光谱证实了铁（III）与海藻酸钠以及CMCT的羧基之间存在静电相互作用，并提出结合模型为三维结构。扫描电子显微镜显示CMCT具有多孔形态，而海藻酸钠及其复合珠具有核 - 层结构。研究了牛血清白蛋白（BSA）在不同pH值下从珠中的溶胀行为、包封效率和释放行为。BSA包封效率相当高（>90%）。发现CMCT在pH 1.2时崩解，海藻酸钠在pH 7.4时侵蚀，而复合珠在酸性条件下能有效保留BSA（>85%）并在pH 7.4时减少BSA释放。结果表明，铁（III） - 海藻酸钠 - CMCT珠可能是一种适用于肠道中位点特异性蛋白质药物递送的聚合物载体。
