Application of 4T-PET fibers/nonwovens for leucocyte filters

Polyethylene terephthalate (PET) fiber with four T-lobe cross section (4T-fiber) has been applied to textile products due to the structural characteristic of micro-grooved channels to provide the high wicking, warming, and elastic properties. In this study, nonwoven (NW) filters composed of one layer of 4T-PET NW (containing 65% 4T-fibers) with one, three, or five layers of polypropylene (PP) NW (4T-PET NW + PP NW x 1, 3, or 5) were proposed for blood filtration to remove leucocytes to reduce blood transfusion-related adverse reactions. The removal rate of leucocytes could be enhanced when the PP NW layers were increased. The presence of the 4T-PET NW on the surface of five layers of PP NW (4T-PET NW + PP NW x 5) filters resulted in a higher erythrocyte recovery rate without losing the capability to remove leucocytes and platelets. Based on the theoretical analysis, leucodepletion filters were further prepared by stacking four 4T-PET NW + PP NW x 5 units together. The optimum filtration results of the filters for filtrating 110 mL of red blood cell concentrates could be prepared when four units of 4T-PET NW + PP x 5 NW placed in a series combination.