放射标记法研究壳聚糖与牛血清白蛋白的自组装超薄膜

基片在两种带有相反电荷的聚电解质溶液中交替吸附 ,其表面形成致密有序的超薄膜的自组装 (ＥＳＡ ｅｌｅｃｔｒｏｓｔａｔｉｃｓｅｌｆ ａｓｓｅｍｂｌｙ)技术是由Ｄｅｃｈｅｒ及其合作者在 1 991年提出[1] ,由于简单易行 ,从一出现就受到了广大研究者的极大兴趣[2～ 4 ] .对生物材料来说 ,这无疑是一项非常重要且方便的表面改性手段 .因为生物材料在生物体内种植时 ,是否会被机体视为异物 ,关键在于机体与材料表面的相互作用 ,而与材料的本体性质基本无关[5] .因此利用这种技术 ,可对生物材料 ,特别是对那些生物相容性不好的材料表面进行…

CHITOSAN/BOVINE SERUM ALBUMIN ULTRATHIN FILMS STUDIED BY RADIO-LABELED METHOD

Chitosan/bovine serum albumin (BSA) ultrathin films were fabricated on modified quartz wafer through layer by layer deposition.The effects of experimental conditions, such as pH value, molecular weight of CS, ionic strength and polyanions coexisting in BSA solution, on the fabrication and the stability of films were investigated with a radio|labeled method. The results show that the absorbed BSA is almost proportional to the number of assembly cycle except the first 2 cycles, and chitosan/BSA films are favorable to be fabricated in chitosan aq AcOH at pH=5.2 as compared with at pH=1.0. When two different molecular weight (MW) chitosans were used ( M η≈1.2×10 5, M η≈1.0×10 6), the lower MW chitosan adsorbs more BSA, but less stable ultrathin films are fabricated. Similar results were obtained that the amount of adsorbed BSA is higher but the films formed are less stable in water than in phosphate buffered saline (PBS). The adsorption of BSA is restricted greatly in the presence of poly(sodium styrene sulfonate) (PSS) mainly because of the competitive adsorption.