新型pH敏感水凝胶的合成及表征

Synthesis and characterization of a new pH-sensitive hydrogel

以乙二胺四乙酸酐(ethylenediaminetetraacetic dianhydride,EDTAD)和丁二胺(butanediamine,BDA)为原料,通过酸酐的N酰化开环聚合反应合成主链含酰胺基、侧链含羧基的直链共聚物(pEDTAD-BDA),然后在磷酸催化剂存在下,pEDTAD-BDA在160℃发生分子内脱水形成含多元酰亚胺的共聚物(pEDTAD-BDA-Imide),最后以丁二胺为交联剂,与pEDTAD-BDA-Imide中的酰亚胺发生N酰化开环反应,生成了侧链含氨基的网络聚合物(BDA-crosslinked-EDTAD-BDA)。该网络聚合物可同时具有完全可降解性、pH敏感性和生物相容性。采用红外光谱和茚三酮显色法对pEDTAD-BDA和BDA-crosslinked-EDTAD-BDA的结构和分子量进行了定性定量表征。

A novel pH-sensitive degradable hydrogel based on ethylenediaminetetraacetic dianhydride （EDTAD） was synthesized. EDTAD reacted with butanediamine through N-acylation ring-opening polymerization of anhydride groups to give a linear copolymer （pEDTAD-BDA） with carboxyl groups on its side chains and amide groups on its backbone, pEDTA-BDA was dehydrated between those carboxyl groups on its side chains and amide groups on its backbone at 160℃with phosphoric acid as a catalyst. A copolymer was produced containing imide groups （pEDTAD-BDA-Imide）. pEDTAD-BDA-Imide was crosslinked by BDA via N-acylation of the imide groups, yielding the desired network polymer with pendant amino groups （BDA-crosslinked-EDTAD-BDA）. BDA-crosslinked-EDTAD-BDA is a promising hydrogel for drug controlled release integrating such advantages as degradahility, good hiocompatihility and pH- sensitivity. FTIR and ninhydrin reaction are employed to qualitatively and quantitatively characterize pEDTAD-BDA and BDA-crosslinked-EDTAD-BDA.