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化学交联葡萄糖基取代聚膦腈水凝胶制备和胰岛素释放研究

Synthesis of Glucosyl Substituent Polyphosphazene Hydrogels and Glucose-Sensitive Insulin Release Behaviors Thereof

【作者】 刘志玲

【导师】 蔡晴;

【作者基本信息】 北京化工大学 , 高分子化学及物理, 2009, 硕士

【摘要】 葡萄糖基聚膦腈不仅具有良好的生物相容性、生物可降解性及降解产物无毒副作用等特点,改变其疏水性侧基和亲水性侧基的比例,还可以调节聚合物的亲水亲油平衡,并且引入化学交联点的葡萄糖基聚膦腈水凝胶与植物凝集素ConA结合后,形成的水凝胶能够应用于对外界葡萄糖浓度变化作出响应的胰岛素控制释放体系,因此葡萄糖基聚膦腈水凝胶在胰岛素给药系统的研究中有很好的应用前景。本文以水溶性好的葡萄糖与甲氧乙氧基共取代聚膦腈为基础,通过与二甘醇胺的取代反应,在聚膦腈侧链进一步引入适量伯氨基,用戊二醛进行化学交联后,再加入Con A形成对葡萄糖具有响应性的水凝胶。测试比较所得水凝胶在不同葡萄糖浓度下的吸水率,并负载胰岛素在两种葡萄糖浓度(4 mg/mL和1 mg/mL)下进行了体外释放行为的测定。具体工作如下;1、通过α-D-葡萄糖与丙酮在氯化锌和磷酸催化剂作用下反应制备1,2:5,6-di-O-异亚丙基-α-D-葡萄糖。2、把二甘醇胺用二碳酸二叔丁酯(BOC2O)和三乙胺在干燥的THF中进行氨基保护,制备出N-叔丁氧羰基保护二甘醇胺。其结构经1H-NMR得到确认。3、用葡萄糖缩二丙酮的钠盐以及N-叔丁氧羰基保护二甘醇胺的钠盐依次与聚二氯磷腈进行取代反应,再用另一种大大过量的亲水亲核取代试剂(本文采用的是甲氧基乙醇)来取代剩余的P—Cl,最后用三氟乙酸脱除保护基获得葡萄糖基聚膦腈。用1H-NMR和IR等手段表征了聚合物结构,并讨论了脱保护时间对聚合物结构的影响。4、把得到的聚合物用戊二醛进行化学交联得到含有化学交联点的水凝胶,再加入Con A形成对葡萄糖具有响应性的水凝胶。对已获得的水凝胶初步进行了性能表征、测试比较所得水凝胶在不同葡萄糖浓度下的吸水率。5、把得到的聚膦腈水凝胶负载胰岛素,在两种葡萄糖浓度(4 mg/mL和1 mg/mL)下进行了体外释放行为的测定。6、制备了pH响应型聚膦腈水凝胶,并对水凝胶的性能进行了初步的测试。

【Abstract】 Glucosyl substituent polyphosphazene has excellent biocompatibility ability and biodegradability.Its degradation products are non-toxic.And the hydrophilicity/hydrophobicity balance of the polymer can be adjusted by changing the ratio of hydrophilic groups and hydrophobic groups.Hydrogel can be prepared by mixing glucosy substituent polyphosphazene and lectin (Con A),which can be used for glucose-sensitive insulin delivery.Because of these excellent properties,glucosy substituent polyphosphazenes has a bright future in the study of insulin release system.In this thesis,Biodegradable and well water-soluble glucose-sensitive polyphosphazene hydrogel has been prepared basing on the specific interaction between polymer-bound glucose and concanavalin A(Con A).A kind of poly(glucosyl-co-methoxyethoxyl-co-2-(2-aminoethoxy) ethoxyl) phosphazene was synthesized by subsequently nucleophilic substitution with 2-[2-((tert-butoxycarbonyl)amino)ethoxy]ethanol,diisopropylidene D-glucose and methoxyethanol,followed by deprotecting treatment with trifluoroacetic acid to restore glycosyl and free amino groups.A chemical crosslinked hydrogel was obtained by react the polymer with glutaraldehyde.After being combined with Con A,the water absorption of the obtained polyphosphazen hydrogel was measured in aqueous solution which with different free glucose concentration.The release rate of insulin from this polyphosphazene hydrogel was measured in different concentration of free glucose in medium from 1 to 4 mg/mL.Details were described as follows:1) 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose was synthesized fromα-D-glucose and acetone using zinc chloride and phosphoric acid as catalysts.2) 2-[2-((tert-butoxycarbonyl)amino)ethoxy]ethanol was synthesized from 2-(2-aminoethoxy)ethanol and di-tert-butyl dicarbonate using triethylamine as acid binding agent.And the product was characterized by ~1H-NMR analysis.3) A kind of poly(glucosyl-co-methoxyethoxyl-co-2-(2-aminoethoxy) ethoxyl)phosphazene was synthesized by subsequently nucleophilic substitution with 2-[2-((tert-butoxycarbonyl)amino)ethoxy]ethanol, diisopropylidene D-glucose and methoxyethanol,followed by deprotecting treatment with trifluoroacetic acid to restore glycosyl and free amino groups. And the product was characterized by IR and ~1H-NMR analysis.The influence of deprotection time on the structure of the polymer was discussed.4) A chemical crosslinked hydrogel was obtained by react the polymer with glutaraldehyde.After being combined with Con A,The water absorption of the obtained polyphosphazen hydrogel was measured in aqueous solution with different free glucose concentration.5) Insulin solution was loaded into the obtained polyphosphazen hydrogel,and in vitro release behavior was determined at different free glucose concentration(4 mg/mL and 1 mg/mL respectively).6) Preparation of pH sensitive hydrogels by introduce the alkaline groups to polyphosphazenes side group,and the initial performance test of hydrogel was carried out.

【关键词】 聚麟腈葡萄糖水凝胶胰岛素体外释放
【Key words】 polyphosphazeneglucosehydrogelinsulinin vitro release
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