College of Materials and Textile Engineering, Jiaxing University, Jiaxing 314001, China.
Acta Biomater. 2014 Jan;10(1):234-43. doi: 10.1016/j.actbio.2013.08.032. Epub 2013 Sep 3.
A novel method for the immobilization of sodium alginate sulfates (SAS) on polysulfone (PSu) ultrafiltration membranes to achieve selective adsorption of low-density lipoprotein (LDL) was developed, which involved the photoinduced graft polymerization of acrylamide on the membrane and the Hofmann rearrangement reaction of grafted acrylamide followed by chemical binding of SAS with glutaraldehyde. The surface modification processes were confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy characterization. Zeta potential and water contact angle measurements were performed to investigate the surface charge and wettability of the membranes. An enzyme-linked immunosorbent assay was used to measure the binding of LDL on plain and modified PSu membranes. It was found that the PSu membrane immobilized with sodium alginate sulfates (PSu-SAS) greatly enhanced the selective adsorption of LDL from protein solutions and the absorbed LDL could be easily eluted with sodium chloride solution, indicating a specific and reversible binding of LDL to SAS, mainly driven by electrostatic forces. Furthermore, the PSu-SAS membrane showed good blood compatibility as examined by platelet adhesion. The results suggest that the PSu-SAS membranes are promising for application in simultaneous hemodialysis and LDL apheresis therapy.
一种将海藻酸钠硫酸盐（SAS）固定在聚砜（PSu）超滤膜上以实现对低密度脂蛋白（LDL）选择性吸附的新方法被开发出来，该方法涉及到膜上丙烯酰胺的光引发接枝聚合以及接枝丙烯酰胺的Hofmann 重排反应，随后用戊二醛将 SAS 化学结合。表面改性过程通过衰减全反射傅里叶变换红外光谱和 X 射线光电子能谱表征得到确认。通过zeta 电位和水接触角测量来研究膜的表面电荷和润湿性。酶联免疫吸附试验用于测量普通和改性 PSu 膜上 LDL 的结合。结果发现，固定有海藻酸钠硫酸盐的 PSu 膜（PSu-SAS）极大地增强了从蛋白质溶液中对 LDL 的选择性吸附，并且吸收的 LDL 可以很容易地用氯化钠溶液洗脱，这表明 LDL 与 SAS 的结合是特异性和可逆的，主要由静电力驱动。此外，PSu-SAS 膜的血小板黏附实验表明其具有良好的血液相容性。这些结果表明，PSu-SAS 膜有望应用于同时进行血液透析和 LDL 吸附治疗。
