海藻酸钠水凝胶的制备及其在药物释放中的应用

摘要

近年来,由于智能水凝胶在药物的控制释放、基因传送、组织工程等领域的应用前景诱人,研究者对智能水凝胶的研究十分活跃.合成类水凝胶常用的单体有丙烯酸及其衍生物、丙烯酰胺及其衍生物等,合成水凝胶具有较好的稳定性,但其生物降解性和生物相容性较差.天然类水凝胶的原料主要有壳聚糖、海藻酸钠、纤维素、淀粉等.由于这些天然多糖具有较好的生物相容性和生物降解性,同时价廉易得,因此,天然类水凝胶在药物控制释放领域更具有优势.海藻酸钠是β-D-甘露糖醛酸(β-D-mannuronic,M)和α-L-古洛糖醛酸(α-L-guluronic,G)按照(1→4)糖苷键连接而成的线型聚合物,每个糖醛酸单元上含有一个羧基,因此,海藻酸钠在中性或碱性条件下呈现聚阴离子电解质的性质.本文综述了海藻酸钠水凝胶的制备方法,包括物理交联法、化学交联法、酶交联法、互穿聚合物网络等；概述了海藻酸钠水凝胶在药物释放中的应用,包括口服给药、皮下给药、黏膜给药、肺部给药、经皮给药等；最后讨论了海藻酸钠水凝胶在研究与应用中存在的问题.%In recent years,due to an attractive application prospect of intelligent hydrogel in drug controlled release,gene transfer,tissue engineering and other fields,the research about intelligent hydrogel is very active.The synthetic hydrogels are mainly prepared by acrylic acid and its derivatives,acrylamide and its derivatives.Synthetic hydrogel has good stability,but its biodegradability and biocompatibility are poor.The raw materials of natural hydrogel include chitosan,sodium alginate,cellulose,starch,etc.These polysaccharides have good biocompatibility and biodegradability,and at the same time,they are cheaper and easier to manufacture.As a result,the natural hydrogels are superior to synthetic hydrogels for drug controlled release.Sodium alginate is an anionic linear polysaccharide composed of (1 →4)-β-D-mannuronic acid (M) and (1 →4)-α-L-guluronic acid (G).Each uronic acid unit contains a carboxyl group,under neutral or basic conditions,sodium alginate shows the properties of the polyanion electrolyte.In this review,the preparation methods of sodium alginate hydrogel are introduced in detail,including physical crosslinking,chemical crosslinking,enzymatic crosslinking,interpenetrating polymer network.The application of sodium alginate hydrogel in drug release is also introduced,including oral administration,subcutaneous administration,mucosal administration,pulmonary administration,transdermal administration.Finally,the problems in research and prospect of sodium alginate hydrogels are discussed.