High-performance separation of protein by the affinity adsorbent of polyethyleneimine-functionalized collagen fibers

The selective adsorption and separation of proteins are crucial in various fields. This study developed a novel affinity adsorbent, prepared by functionalizing collagen fibers with polyethyleneimine (CFs-PEI). Its adsorption and chromatographic separation performance for proteins were evaluated. It was found that the CFs-PEI exhibited satisfactory adsorption capacities of 462.29 mg/g for bovine serum albumin (BSA) and 159.99 mg/g for bovine hemoglobin (BHb) at pH 5.0. Furthermore, the separation factor (SF_BSA/BHb) for BSA to BHb in a binary mixture solution at pH 5.0 reached 69.67, attributable to their distinct electrostatic interactions with CFs-PEI. In the chromatographic separation process, the BSA and BHb could be completely separated by stepwise elution with acetate buffer and citrate buffer. Meanwhile, the CFs-PEI column exhibited favorable reusability, maintaining a recovery rate exceeding 80 % for at least four cycles. This work presented a promising method for protein adsorption and separation using a naturally derived collagen fibers-based adsorbent, which was expected to show potential for applications ranging from biomolecule adsorption and separation to biomedical fields and food industries.