磁性壳聚糖微球对牛血清白蛋白的吸附性能

在微乳液体系中, 以戊二醛为交联剂制备了磁性壳聚糖纳米粒子(Fe₂O₃-CS). 采用透射电子显微镜(TEM)、红外光谱(IR)、振动样品磁强计(VSM)等手段对纳米粒子进行表征. 结果表明, 纳米粒子的粒径在40 nm左右, 分散性良好, 具有较好的磁响应性能. 以碳二亚胺(EDC)为活化剂, 研究了Fe₂O₃-CS纳米粒子对牛血清白蛋白(BSA)分子的吸附性能, 并使用原子力显微镜(AFM)、紫外分光光度计(UV)进行表征. Fe₂O₃-CS粒子对BSA 的吸附大致符合Langmuir吸附模型, 298 K时饱和吸附量约为250 mg·g^-1, 吸附常数为0.007 L·mg^-1. 将BSA-粒子分散在不同pH的缓冲溶液中, 研究BSA-粒子复合物的稳定性. 用聚丙烯酰氨凝胶电泳(SDS-PAGE)对结果进行表征, 发现在碱性条件下BSA分子能从磁性粒子表面脱附下来.

Adsorption of Bovine Serum Albumin onto Magnetic Chitosan Microspheres

Magnetic chitosan nanoparticles(Fe₂O₃-CS) were prepared in microemulsion by crosslinking method. The transmission electron microscopy (TEM), Fourier transforminfrared spectrophotometry (FT-IR) and vibrating specimen magnetometer (VSM) were used to characterize the nanoparticles. The mean diameter of the particles was about 40 nm with good dispersibility and magnetic response. The bovine serum albumin (BSA) was connected onto the surface of the magnetic nanoparticles with carbodiimide hydrochloride (EDC) as the activator. The products were then characterized by atomic force microscope (AFM) and ultraviolet spectrometer (UV). The results showed that the nanoparticles had a good adsorbability of the BSA. The adsorption isotherm of the BSA on the magnetic chitosan microspheres basicly obeyed the Langmuir model, with a maximum adsorption capacity of 250 mg·g ^-1 and an adsorption equilibrium constant of 0.007 L·mg^-1. The stability of the particles-BSA complex in phosphate buffer solution (PBS) with different pH was also studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that BSA was desorbed frommagnetic particles under alkaline condition.