Evaluation of hydrophobic charge-induction ligand efficiency for protein adsorption in one single cycle

Ligand is an essential part of the cost of adsorbent preparation, which needs to be carefully selected and evaluated. In this paper, we introduced ligand efficiency (Le) with three levels (recovery, preparation and cost) to form a selection strategy for evaluation of the efficiency of hydrophobic charge-induction ligand. These functions were calculated from static/dynamic binding capacity, desorption efficiency, coupling efficiency and ligand cost. Nine kinds of ligand were used to demonstrate this strategy. The coupling efficiency was determined by preparing the adsorbents with different kinds and densities of ligand. These adsorbents were characterized by FT-IR, SEM. Then adsorption equilibrium, adsorption kinetics, and frontal adsorption experiments were used to test the adsorption and desorption performance of these adsorbents. Finally, Les of recovery, preparation and cost were calculated. The results showed there were apparent differences in Les between ligand types and densities under static and dynamic adsorption conditions. 4FF-Tryptophan with 52 μmol/g adsorbent had the best performance with the lowest static/dynamic Le of recovery, preparation and ligand cost. Compared with those methods evaluated by static saturated adsorption capacity or dynamic binding capacity at 10% breakthrough, the selection strategy based on ligand efficiency is more suitable for subsequent research and industrial amplification.