Preparation of immuno-affinity membranes for cholesterol removal from human plasma.
Anti-low density lipoprotein antibody (anti-LDL) immobilized polyhydroxyethylmethacrylate (pHEMA) based membrane was prepared for selective removal of cholesterol from hypercholesterolemic human plasma. In order to further increase blood-compatibility, a newly synthesized comonomer, methacryloylamidophenylalanine (MAPA) was included in the membrane formulation. p(HEMA-MAPA) membranes were produced by a photopolymerization and then characterized by swelling tests, SEM and contact angle studies. Blood-compatibility tests were also investigated. The water swelling ratio of the p(HEMA-MAPA) membrane increases significantly (133.2.9%) compared with pHEMA (58%). p(HEMA-MAPA) membranes have large pores around in the range of 5-10 microm. All the clotting times increased when compared with pHEMA membranes. Loss of platelets and leukocytes was very low. The maximum anti-LDL antibody immobilization was achieved around pH 7.0. Immobilization of anti-LDL antibody was 12.6 mg/ml. There was a very low non-specific cholesterol adsorption onto the plain p(HEMA-MAPA) membranes, about 0.36 mg/ml. Anti-LDL antibody immobilized membranes adsorbed in the range of 4.5-7.2 mg cholesterol/ml from hypercholesterolemic human plasma. Up to 95% of the adsorbed LDL antibody was desorbed. The adsorption-desorption cycle was repeated 10 times using the same membrane. There was no significant loss in the adsorption capacity.
Denizli
Adil
A
Hacettepe University, Department of Chemistry, Biochemistry Division, Ankara, Turkey. denizli@hacettepe.edu.tr
D000327:Adsorption; D000906:Antibodies / Q000276:immunology; D002784:Cholesterol / Q000097:blood / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood*; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning
D000906:Antibodies; D008567:Membranes, Artificial; D002784:Cholesterol