Optimal heparin surface concentration and antithrombin binding capacity as evaluated with human non-anticoagulated blood in vitro.
Contact between blood and a biomaterial surface takes place in many applications and is known to activate the coagulation and complement systems. Heparin surface coatings have been shown to reduce blood activation upon contact with artificial surfaces. To establish the optimal heparin surface concentration, blood was incubated in a tubing loop model at 37 degrees C. The tubing was coated with different surface concentrations of heparin and rotated at three different velocities. We demonstrate that the blood compatibility of a surface with regard to coagulation, complement, and platelet activation can be improved by increasing the heparin surface concentration in the 6-12 pmol antithrombin/cm2 concentration interval. The binding of factor H is not influenced by the increased heparin surface concentration, suggesting that this factor is not the primary regulator of complement on heparin surfaces. In addition, the heparin coating has no effect on the complement activation that occurs on gas surfaces in extracorporeal circuits.
Andersson
Jonas
J
Department of Oncology, Radiology and Clinical Immunology, Section of Clinical Immunology, Rudbeck Laboratory C5, Uppsala University Hospital, SE-751 85 Uppsala, Sweden. jonas.andersson@klinimm.uu.se
Sanchez
Javier
J
Ekdahl
Kristina Nilsson
KN
Elgue
Graciela
G
Nilsson
Bo
B
Larsson
Rolf
R
D000991:Antithrombins / Q000378:metabolism*; D001672:Biocompatible Materials / Q000378:metabolism*; D001769:Blood / Q000378:metabolism*; D001773:Blood Cells / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D017242:Complement Factor H / Q000378:metabolism; D006493:Heparin / Q000378:metabolism*; D006801:Humans
D000991:Antithrombins; D001672:Biocompatible Materials; C493495:CFH protein, human; D017242:Complement Factor H; D006493:Heparin