基于酵母发酵致孔的小麦麸质蛋白/聚丙烯酸钠复合多孔水凝胶的合成及溶胀性能

Synthesis, characterization, and swelling behaviors of wheat gluten/poly (sodium acrylate) porous composite hydrogel produced by yeast fermentation

  • 摘要: 以1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)活化丙烯酸(AA)羧基与小麦麸质蛋白(WG)接枝交联,酵母菌素分解WG中淀粉等多糖产生的CO2作为孔模板,水溶液中自由基聚合制备了WG/聚丙烯酸钠(PNaA)多孔复合水凝胶(WG/PNaA)。FTIR分析表明,WG链上—OH、—NH2等与AA成功接枝,并与中和的丙烯酸钠(NaA)在N,N'-亚甲基双丙烯酰胺(MBA)存在下聚合交联。场发射SEM(FESEM)证实,适量酵母菌素在WG体系中产生的CO2可作为孔模板,在WG/PNaA网络中形成蜂窝状多孔结构,这种孔状结构不仅提高了WG/PNaA复合水凝胶在蒸馏水和生理盐水中的平衡溶胀倍率,也使其Schott's准二级动力学起始溶胀速率常数Kis提高至无酵母致孔样的5倍,Ritger半经验方程分析也证实其扩散系数n=0.5642,为non-Fickian溶胀,即孔状网络在凝胶溶胀初期有利于水分子快速扩散。考察了WG/PNaA复合水凝胶在蒸馏水-生理盐水、pH为2.2和7.4时磷酸缓冲溶液中的溶胀敏感性。结果表明,经过5次反复溶胀-去溶胀循环后仍具有良好的响应性,即多孔WG/PNaA复合凝胶同时具有灵敏可逆的盐和pH敏感性,为该水凝胶在药物控释领域应用提供了潜在可能。

     

    Abstract: Wheat gluten (WG) reacted with acrylic acid (AA) in the promotion of 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) to produce WG-AA chains. Following, yeast decomposed the starch that existed in WG to produce CO2, which used as pore template to prepare a novel porous WG/poly(sodium acrylic)(PNaA) composite hydrogel(WG/PNaA) via free-radical graft copolymerization of sodium acrylate and WG-AA chains in the aqueous solution. FTIR spectra demonstrate that AA is grafted onto the WG chains, and the composite hydrogel is formed successfully in the presence of cross-linker N,N'-methylene discrylamide (MBA). Field emission SEM (FESEM) also displays that incorporating the proper amount of yeast into the hydrogel matrix can form porous interlinked channels within the composite hydrogel network. The porous WG/PNaA composite hydrogel shows greater equilibrium swelling capacity both in distilled water and in 0.9% NaCl solution, and the Schott's second-order swelling dynamic constant Kis is improved to 5 times compared with non-yeast exited hydrogel. Ritger's semi-empirical equation analysis also confirms that the water transport mechanism of the porous WG/PNaA composite hydrogel is non-Fickian diffusion type (n=0.5642), which means, the porous structure of the composite hydrogel is benefit to the water molecules spread quickly at the beginning swelling. The swelling-deswelling behaviors of the porous WG/PNaA composite hydrogel in distilled water-0.9% NaCl solution and in pH 2.2 and pH 7.4 phosphate buffer solution were assessed and the results show that the composite hydrogel exhibits excellent salt, pH-dependent swelling responsiveness after 5 times repeated swelling, which providing a potential application in the field of drug controlled-release.

     

/

返回文章
返回