In vitro characterization of a membrane-based low-density lipoprotein affinity adsorption device.
The objective of this study was to explore the use of microporous membranes as an alternative substrate to porous beads in affinity adsorption of low-density lipoprotein (LDL) for therapeutic purposes. Flat sheet immunoaffinity membranes containing a polyclonal antibody preparation were utilized as the affinity substrate. The antibody was covalently immobilized to the surface through a poly(ethylene glycol) (PEG) spacer. Equilibrium adsorption of LDL from plasma was measured. Adsorption from plasma and elution of bound LDL using citrate buffer were studied as a function of flow rate. Specific capacity was as great as 2 mg apolipoprotein B per milliliter membrane volume. The superior transport properties of the membrane allowed rapid adsorption and regeneration, which translated to a large number of adsorptive cycles that can be performed within a given treatment time. On the basis of in vitro performance characteristics, it is estimated that an immunoaffinity membrane device can provide a reduction in patient plasma LDL concentration comparable to that provided by packed columns, but with almost an 80% reduction in the device volume.
University of Wisconsin, Madison, USA.
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D006801:Humans; D007163:Immunosorbent Techniques / Q000295:instrumentation*; D008077:Lipoproteins, LDL / Q000302:isolation & purification*; D008567:Membranes, Artificial; D010956:Plasmapheresis / Q000295:instrumentation* / Q000379:methods
D008077:Lipoproteins, LDL; D008567:Membranes, Artificial