Poly(ethyleneimine) modified filters for the removal of leukocytes from blood

Abstract

Polyurethane membrane filters and filters coated with poly(ethyleneimine) were used to investigate the influence of leukocyte adhesion during filtration. Treatment of the filters with an aqueous solution of 1% (w/v) poly(ethyleneimine) (PEI) led to the introduction of amine groups at the filter surfaces, as was confirmed by X-ray photoelectron spectroscopy. The modification procedure did not significantly change the porous structure in the filters, as was demonstrated by SEM and porometry. Using 14C-labeled poly(ethyleneimine) it was shown that nearly a complete coverage (approximately 0.1 mg/m2) was achieved that did not desorb from the filter surface during contact with blood plasma. When the filtration was carried out with purified leukocytes in the absence of red cells, platelets, and blood plasma, the number of cells removed by modified filters (> 95%) was significantly higher as compared to the removal with unmodified filters (approximately 80%). However, no significant differences between the filters were found when the filtration was performed with whole blood. This finding was unexpected, because it was shown before that immobilization of poly(ethyleneimine) on solid polyurethane film, surfaces promoted the adhesion of leukocytes from whole blood. Apparently, the adhesive properties of the PEI diminish during filtration. Filter coating of commercial leukocyte filters composed of polyester fibers also had no effect on the removal of leukocytes from whole blood. It was postulated that morphological factors, such as filter shape, roughness, tortuosity, and porosity rather than the physicochemical properties of the filter surface influence cell adhesion to the filter surface, and through that the filtration process.

Functionalization of nickel nanowires with a fluorophore aiming at new probes for multimodal bioanalysis

“…In some situations, such as in blood transfusion, it is necessary to reduce the concentration of leukocytes in blood, in order to prevent leukocyte-mediated adverse effects [51,54,55]. Therefore, the materials described here may contribute to develop additional tools for the depletion of leukocytes, taking advantage of the ferromagnetic properties of nickel nanowires.…”

“…Previous studies, which employed leukocyte suspensions, have shown that surface modification with PEI of polyurethane films/filters improved leukocyte removal and adhesion to surfaces; however, no improvement was found when whole blood was used [51,52]. Leukocytes have a negative zeta potential [53] and therefore are prone to interact strongly with the positive surface of the NiNW.…”

Functionalization of magnetic nanowires for biomedical applications

“…This is important for clinical aspects because in some cases the leukocytes have to be removed from the blood. For example, in blood transfusions the concentration of leukocytes in the blood has to be reduced to prevent leukocyte-mediated adverse effects (Bruil et al, 1993;Bruil et al, 1995;Singh and Kumar, 2009 Many of the nanowires, with magnetic nanowires being no exception, are combined with Au. By introducing the Au segments that take part in the (bio)functionalization, the main and crucial step towards final applications is made.…”

An in vitro system for testing leucocyte and leukaemic cell line adhesion to synthetic fibres

“…The adherence of leucocytes to glass fibres has been used to remove leucocytes from blood. Several investigations have been conducted to identify natural or synthetic fibres to which leucocytes bind (Rasp et al , 1981; Lang et al , 1988; Bruil et al , 1992, 1993). Several materials have been selected for their biocompatibility or capacity to react with leucocytes and used in filters to deplete blood products of leucocytes.…”