壳聚糖改性丝素合金膜的制备及其相关性质研究

The Preparation and Properties of Modified Silk Fibroin Membranes by Chitosan

以无毒氧化葡萄糖醛作交联剂 ,采用溶液共混交联法制备壳聚糖改性丝素合金膜。用 FTIR、DSC表征其结构 ,测定其等电点、力学性能、不同 p H条件下的溶胀率和对模型药物 5 - Fu的渗透性。结果表明 :改性丝素合金膜中丝素和壳聚糖分子间存在着强烈的氢键相互作用及良好的相容性。改性膜的等电点对应的 p H值是 5 .35 ,而丝素膜的等电点是 4 .5。改性膜的力学性能优于单组分膜 ,当壳聚糖含量为 4 0 %～ 6 0 %时 ,具有最大的抗张强度和拉伸率 ,分别为 71.4～ 72 .7MPa和 2 .96～ 3.82 %。改性丝素合金膜对 5 - Fu的渗透量与壳聚糖的含量和时间成正相关关系 ,渗透系数随 p H值增大 (5→ 9)先逐渐减小然后略有增大 ,在 p H=7时最小。

The Modified silk fibroin membranes were prepared by mixing the aqueous solutions of both silk fibroin and chitosan with the use of oxidized glucose aldehyde as a crosslinking agent. It was characterized by FT-IR,DSC,measurements of membrane-potential and mechanical properties,the water swelling ratios and permeability coefficient for model drug 5-Fu in the different pH buffer solutions. It was shown that there were some strong hydrogen bond interaction and good compatibility between silk fibroin and chitosan molecules in the modified silk fibroin films. The isoelectric point of modified fibroin film was about pH 5.35,but that of natural fibroin film was around pH 4.5. It was also found that the mechanical properties of modified fibroin films were much better than those of fibroin itself. Its tensile strength and breaking elongation were greatly enhanced with the increase of chitosan content and their maximum values were as high as 71.4～72.7 MPa and 2.96%～3.82% respectively,at the composition of 40 wt%-60 wt% chitosan. Its coefficient of permeability decreased firstly and then increased slowly with the change of the pH value of solutions from pH 5 to pH 9,and the minimum coefficient of permeability was observed when pH=7.