Preparation of tryptophan modified chitosan beads and their adsorption of low density lipoprotein

An adsorbent with good adsorption perform-ance for binding low density lipoprotein (LDL) was synthe-sized through a simple preparation procedure. The phase-inversion technique was employed to form macropor-ous chitosan beads, which were then simultaneously acti-vated, cross-linked and connected with a long spacer arm via the reaction with ethyleneglycol diglycidylether (EGDE). Tryptophan (Trp) was subsequently coupled to the ep-oxy-activated beads. This adsorbent demonstrated satisfac-tory adsorption capacity and selectivity for LDL, and it also exhibited excellent blood compatibility. The effect of spacer arms with different length on the adsorption selectivity was investigated experimentally, and the mechanism was ana-lyzed.