In vitro hemocompatibility testing of biomaterials according to the ISO 10993-4.
The development of synthetic materials, textured polymers and metals and their increasing use in medicine make research of biomaterials' hemocompatibility very relevant. Problems arise from the polymorphism and diversity of the different materials, the static and dynamic test models and the patients' individual biologic factors. First, methods, models, tests as well as preanalytical factors have to be standardized according to the current knowledge in medicine laid down in the ISO 10993 part 4. The routine controls used in clinical chemistry and hematology have to be performed. Information about normal ranges (mean value, standard deviation, 95% confidence interval) should be provided. Tests have to be performed within a minimal delay of usually 2 h since some properties of blood change rapidly following collection. Various conditions (depending on the wall shear rate) were simulated within the centrifugation system and a Chandler system. Qualities and aspects of hemocompatibility such as platelet activation, oxidative burst, hemolysis, fibrinolysis, fibrin formation, generation of thrombin, contact activation, and complement activation were analysed and the results were entered non-dimensionally into a non-dimensional score system, where 0 points stand for the best and 65 points for the worst evaluation. We found a good correlation between the total score and contact activation, thrombin generation and leukocyte activation in a low shear stress system and a good correlation between the total score and thrombin generation, hemolysis and platelet activation in the high shear stress system. Further on the effect of additives and sterilization procedures can be measured. The concepts presented underline the relevance/importance of an efficient diagnostic approach to hemocompatibility that takes account of clinical and socio-economic concerns.
Abteilung Klinische Hämostaseologie und Transfusionsmedizin, Haus 75, Universitätskliniken, D-66421 Homburg, Germany. htusey@universitaetskliniken-saarland.de
Ulrich Theo
UT
Seyfert
Volker
V
Biehl
Joachim
J
Schenk
D001672:Biocompatible Materials / Q000592:standards*; D001769:Blood; D001792:Blood Platelets; D001793:Blood Preservation / Q000379:methods / Q000592:standards; D005858:Germany; D006461:Hemolysis; D018056:Hemorheology / Q000379:methods / Q000592:standards*; D006487:Hemostasis; D006801:Humans; D007391:International Cooperation; D008422:Materials Testing / Q000379:methods* / Q000592:standards*; D015539:Platelet Activation; D010973:Platelet Adhesiveness; D012016:Reference Values; D013314:Stress, Mechanical; D013499:Surface Properties; D013917:Thrombin / Q000032:analysis
D001672:Biocompatible Materials; D013917:Thrombin