Preparations and applications of polyethyleneimine-immobilized cellulose fibers for endotoxin removal

Abstract

Through the immobilization of polyethyleneimine (PEI) onto cellulose fibers, novel fibrous adsorbents (Cell-PEI fibers) for the removal of endotoxins were prepared. Anion-exchange capacity and pore size (molecular mass exclusion, Mlim) of the Cell-PEI fibers were readi]y adjusted by changing the ratio of polyethyleneimine and sodium carbonate to cellulose during suspension. The adsorption of endotoxin by the fibers increased with anion-exchange capacity of the fibers, and decreased with increase in the ionic strength of the buffer. The Cell-PEI fibers (anion-exchange capacity 1.1 to 3.0 meq g−1) showed high endotoxin-adsorbing activity at pH 5 to 9 and ionic strength of μ=0.05 to 0.2. The adsorbing activity for aicidic protein such as bovine serum albumin (BSA) increased with Mlim and the anion-exchange capacity of the fibers, but decreased with increase in the ionic strength of the buffer. The Cell-PEI fibers (Mlim: 2000, anion-exchange capacity: 1.1 meq g−1) selectively reduced endotoxins in various protein solutions containing endotoxins at pH 7 and μ=0.05. The residual concentration of endotoxins in the protein solutions decreased to less than 0.1 ng ml−1, and recovery rate of the protein was over 98% in all cases. © 1995, The Society of Polymer Science, Japan. All rights reserved.