Synthesis and Characterization of Novel Adsorbents with Different Ligand Composition for Bilirubin Conjugated with Albumin

Abstract

The chemical composition and conformation of ligand immobilized on bilirubin adsorbent have been proposed as the key factors to determine the affinity and specificity for bilirubin in patients' plasma. However, up to now, the effects of ligand composition on bilirubin removal are not clear. In this study, we selected human serum albumin (HSA), long carbolic chain and amino groups as the functional groups of ligand immobilized on Sepharose CL‐4B to discuss the effects. The results showed that amino groups and hydrophobic carbonic chains could be very important factors to adsorb bilirubin conjugated with albumin. The contribution of HSA to the adsorption may be owing to its dimensional obstruction for macromolecules approaching, thereby nonspecific adsorption was decreased in plasma. The adsorption capacity for bilirubin increased obviously with the rise of initial concentration of bilirubin in plasma. The adsorption capacity was 7.52 mg/mL gel for bilirubin in albumin phosphate buffer (pH 7.0) with bilirubin concentration of 377 mg/L, while it only got to 3.64 mg/mL in human plasma at the same concentration. The adsorption microenvironment with pH 7.0–8.0, higher temperature (30–40°C) and lower ionic strength were beneficial to the bilirubin adsorption.

Keywords:

• Bilirubin removal
• ligand
• HSA
• bilirubin albumin conjugates

Acknowledgment

We are grateful to the National Natural Science Foundation of China (No. 20375006, No. 20435020) for the financial support of this work.