Characterization of polyethylene membrane for plasma separation

Three types of polyethylene hollow fiber membranes (Mitsubishi, Tokyo) were evaluated for plasma separation: EHF-Type 1 (lowest porosity and smallest inner diameter), Type 2 (medium porosity and diameter), and Type 3 (highest porosity and largest inner diameter). Characterization of these membranes led to the selection of the Type 3 membrane as the best, based on in vitro studies of filtration and sieving properties. Analysis of the data suggests that pore size and pore number (density) are more optimal for this membrane. Ex vivo studies of the Type 3 membrane showed high sieving (greater than 0.9) for albumin, total protein, and total cholesterol; each was stable over time. No significant hemolysis was observed.