Reduced platelet adhesion and blood coagulation on cross-linked albumin films

Surface-induced thrombosis is a major complication associated with blood-contacting biomaterials. Cross-linked albumin films possessing native albumin characteristics such as resistance to cell adhesion and drug binding ability are available for improving the blood compatibility of biomaterial surfaces. In the present study, we aimed to evaluate the blood compatibility of cross-linked albumin films. Platelet adhesion analysis showed that albumin film coated substrates exhibited very low platelet adhesion, and platelet adhesion was further suppressed by loading the antiplatelet drug, cilostazol, into the film. Monitoring the coagulation process of whole blood using a coaxial-cylinder rotational viscometer showed that the initial time of coagulation in albumin film coated cylinders was delayed compared with that in uncoated cylinders, suggesting that activation of the intrinsic coagulation cascade was reduced on the albumin film coated surface. Thus, surface coating with cross-linked albumin films is a promising approach to conferring biomaterials with antithrombogenic surfaces due to the resistance to platelet adhesion and the antiplatelet drug-releasing capability afforded by the films.