An adsorption behavior of low-density lipoprotein onto cholesterol-modified dextran studied by a quartz crystal microbalance

The use of quartz crystal microbalance (QCM) for on-line monitoring of the adsorption of low-density lipoprotein (LDL) onto cholesterol-modified dextran (CMD) was described. Kinetics studies were made and molecule interaction mechanism was discussed. Experimental results showed that kinetic curves fitted Langmuir adsorption equation quite well. When LDL concentrations (ng/μl) were 9.9, 12.38 and 14.14, respectively, the apparent rate constants (s−1) and adsorption capacities (ng/cm2) were estimated to be 0.0477, 0.0536, 0.0628 and 124.5, 161.6, 194.3, respectively. The maximal LDL adsorption capacity attained 329.6 ng/cm2 and the adsorptive efficiency was calculated to be 72.91%. Moreover, a new method to evaluate the adsorption behavior was provided.