A new model for evaluation of biocompatibility: combined determination of neoepitopes in blood and on artificial surfaces demonstrates reduced complement activation by immobilization of heparin.
An in vitro technique was developed for assessment of the biocompatibility of materials for use in clinical applications. Artificial materials were exposed to blood, and the resulting complement activation was quantified both in the plasma and on the material surface by enzyme immunoassays based on monoclonal antibodies specific for neoepitopes exposed in complement activation products. Several materials were evaluated, and the effect of surface modifications, including end-point immobilized heparin, was studied. The results revealed widely varying complement activation properties of the different materials and confirmed that heparin markedly improves biocompatibility. The present method is superior to analysis limited to either the fluid phase or solid phase since certain materials adsorb activation products (exemplified by Tecoflex) whereas others do not although activation was evident from fluid-phase assay (silicone). Furthermore, direct determination of activation-specific neoepitopes on the surface represents an improvement compared with previously described methods for detection of adsorbed components.
Mollnes
T E
TE
Department of Immunology and Transfusion Medicine, Nordland Central Hospital, Bodø, Norway.
Riesenfeld
J
J
Garred
P
P
Nordström
E
E
Høgåsen
K
K
Fosse
E
E
Götze
O
O
Harboe
M
M
D001672:Biocompatible Materials / Q000494:pharmacology*; D003167:Complement Activation / Q000187:drug effects*; D003179:Complement C3b / Q000187:drug effects; D015936:Complement C5a / Q000187:drug effects; D015938:Complement Membrane Attack Complex / Q000187:drug effects; D000939:Epitopes / Q000097:blood*; D006493:Heparin / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007840:Latex / Q000494:pharmacology; D008567:Membranes, Artificial; D008954:Models, Biological; D011140:Polyurethanes / Q000494:pharmacology; D011143:Polyvinyl Chloride / Q000494:pharmacology; D012828:Silicones / Q000494:pharmacology; D013499:Surface Properties
D001672:Biocompatible Materials; D015938:Complement Membrane Attack Complex; D000939:Epitopes; D007840:Latex; D008567:Membranes, Artificial; D011140:Polyurethanes; D012828:Silicones; C062725:Tecoflex; D003179:Complement C3b; D015936:Complement C5a; D011143:Polyvinyl Chloride; D006493:Heparin