PREPARATIONS AND APPLICATIONS OF POLYETHYLENEIMINE-IMMOBILIZED CELLULOSE FIBERS FOR ENDOTOXIN REMOVAL

Through the immobilization of polyethyleneimine (PEI) onto cellulose f ibers, novel fibrous adsorbents (Cell-PEI fibers) for the removal of e ndotoxins were prepared. Anion-exchange capacity and pore size (molecu lar mass exclusion, M(lim)) of the Cell-PEI fibers were readily adjust ed 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 w ith 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-a dsorbing activity at pH 5 to 9 and ionic strength of mu = 0.05 to 0.2. The adsorbing activity for acidic protein such as bovine serum albumi n (BSA) increased with M(lim) and the anion-exchange capacity of the f ibers, but decreased with increase in the ionic strength of the buffer . The Cell-PEI fibers (M(lim): 2000, anion-exchange capacity: 1.1 meg g(-1)) selectively reduced endotoxins in various protein solutions con taining endotoxins at pH 7 and mu = 0.05. The residual concentration o f 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.