ENDOTOXIN REMOVAL WITH POLY(ETHYLENEIMINE)-IMMOBILIZED ADSORBERS - SEPHAROSE 4B VERSUS FLAT SHEET AND HOLLOW-FIBER MEMBRANES

Poly(ethyleneimine) was immobilized on poly(vinyl alcohol)-coated nylo n flat sheet membranes, poly(vinyl alcohol) and poly(ethylenevinyl alc ohol) hollow fibre membranes as well as Sepharose 4B, The resulting po ly(ethyleneimine)-immobilized adsorbers were used for removal of E. co li derived endotoxin from buffers and bovine serum albumin solutions. The efficiency of poly(ethyleneimine) proved to be constant over a wid e pH range, including phosphate buffered saline. The performance depen ded upon the matrix type employed: endotoxin clearance factors varied from 100 to 120 000 in protein-free solutions and 40 to 33 000 in solu tions of bovine serum albumin using 6000 EU/ml as feed concentration. The best adsorber was the flat sheet membrane-immobilized poly(ethylen eimine), followed by the hollow fibre-immobilized poly(ethyleneimine) and poly(ethyleneimine)-Sepharose. The factors influencing endotoxin c learance were the mass transport (convective systems were superior to the diffusive system), the chemical composition and the surface struct ure of the underlying matrix. (C) 1998 Elsevier Science B.V.