基于QCM-D的天然多糖材料的蛋白吸附研究

Quartz crystal microbalance study of protein adsorption on natural polysaccharides

采用QCM-D和AFM等技术研究比较了海藻酸钙和壳聚糖两种天然多糖材料经旋转成膜后的表面形貌、亲疏水性、水合过程及蛋白吸附和解吸行为。结果发现,海藻酸钙相比壳聚糖具有更好的亲水性,在生理环境中的水合过程达到平衡较快,且水合程度较高,这也影响材料的蛋白吸附性能。白蛋白吸附和洗脱实验表明,水合程度较高的海藻酸钙初始吸附蛋白量较少,但海藻酸钙吸附的蛋白量在PBS洗脱后反而较大。而蛋白层|ΔD/ΔF|值在洗脱后减小,表明残留的蛋白层发生一定程度的构象变化,结构相对致密,其粘弹性变小。用3种动力学模型拟合蛋白吸附动力学过程发现Langmuir模型拟合度较高,且壳聚糖薄膜的蛋白吸附过程比海藻酸钙具有更小的速率常数k,达到吸附平衡较缓慢。

Two typical natural polysaccharides, chitosan and alginate were selected. It was investigated the protein adsorption behavior,surface topography, hydrophilicity and hydration of the above materials with the QCM-D and AFM technique. The result revealed, calcium alginate cost less time in hydration process and reached higher hydrature compared with chitosan, which effect the protein adsorption behavior. The protein adsorption mass on calcium alginate was less than chitosan. The result, however, was opposite after disadsorption. Besides, ｜△D/△F｜ value of protein layer which is related with viscoelastic properties decreased after disadsorption,owing to the conformational change of surplus protein. Three kinesics models has been used to fit the adsorption curve. The data suggested that Langmuir model was better,and adsorption curve indicated that rate constant of calcium alginate was more than chitosan.