基于乙二胺四乙酸酐和丁二胺的pH敏感水凝胶的合成与表征

Synthesis and Characterization of a Biodegradable pH-Sensitive Hydrogel Based on Ethylenediamine Tetraacetic Dianhydride and Butanediamine

以乙二胺四乙酸酐(EDTAD)和丁二胺(BDA)为原料,通过酸酐的N-酰化开环反应制备侧链含羧基的直链聚合物(pEDTAD-BDA);然后以二环己基碳二亚胺(DCC)活化pEDTAD-BDA中的羧基,以BDA为交联剂,制得单体间连接全部为酰胺键、侧链只含羧基的交联网络聚合物BDA-crosslinked-EDTAh-BDA。采用氢核磁共振(1H-NMR)、碳核磁共振(13C-NMR)和茚三酮显色法对pEDTAD-BDA的结构和数均分子量进行了表征。pH敏感性测试表明,BDA-crosslinked-pEDTAD-BDA在pH=12介质中的溶胀率约为pH=3和pH=7介质中溶胀率的5倍,表现出敏锐的pH响应性。该网络聚合物可望成为一种集完全可降解性、良好生物相容性和pH敏感性于一身的医用水凝胶材料。

A novel degradable pH-sensitive hydrogel was synthesized from ethylenediamine tetraacetic dianhydride （EDTAD） and butanediamine （BDA） ： firstly, EDTAD reacted with butanediamine （BDA） through N-acrylation of anhydride groups in EDTAD with amino groups in BDA, producing a linear copolymer containing pendant carboxyl groups （pEDTAD-BDA）; then, the carboxyl groups in pEDTAD-BDA were activated by N, N ＇- dicyclohexylcarbodiimide （DCC） and thereafter condensed with BDA as crosslinking agent, yielding the desired network polymer with pendant earboxyl groups （BDA-crosslinked-EDTAD-BDA）. Proton nuclear magnetic resonance spectroscopy （^1H-NMR）, carbon-13 NMR （^13 C-NMR） and ninhydrin reaction were employed to characterize the chemical structures and average-number molecular weight of pEDTAh-BDA. The pH sensitivity tests indicate that BDA-crosslinked-EDTAD-BDA exhibites about 5 times the swelling ratio in pH = 12 as compared with those in pH = 3 and 7 media, showing significant pH response. BDA-crosslinked-EDTAD-BDA is a type of hydrogel potentially featured with biodegradability, sound biocompatibility and pH sensitivity.