Blood‐compatibility‐water‐content relationships for radiation‐grafted hydrogels

Abstract A series of radiation‐grafted hydrogels with water contents ranging from 10% to 90% have been prepared. When evaluated by the vena cava ring test, increasing amounts of adherent thrombus were found in rings with lower graft water contents. Using a baboon arteriovenous shunt evaluation system, platelet thromboembolic consumption was found to be directly proportional to graft water content. Hydrogels studied by the renal embolus ring test were found to cause numerous infarcts in the kidneys of test animals. Results from these studies do not support “water‐content‐blood‐compatibility” hypotheses which have been suggested for hydrogels. Results obtained with a series of hydrophilic‐hydrophobic copolymers suggest that a balance of polar and apolar sites at a polymer‐surface may be important for blood compatibility. The significance of results from the three evaluation systems used is discussed.