Real-time Evaluation of Hemocompatible Materials by Human Platelets as an Alternative to Animal Experimentation

Abstract

To establish alternative methods to animal testing and experimentation for hemocompatible materials, we had been developed an apparatus consisting of a modified cone and plate-type rheometer combined with an upright epi-fluorescence microscope. Through this apparatus, we could conduct real-time evaluation of platelet-material interactions, the initial event of thrombus formation, under shear flow conditions using small platelet suspension volumes (7.5∼500 µl per material). The use of human blood from a blood bank allows easy access to large amounts of human blood and does not require medical doctors and volunteer donors to draw the blood. Therefore, to test the hemocompatibility of materials, we used human blood from a blood bank. In order to compare the properties of platelets between fresh and bank blood, the number of adhering platelets, the trigger of the thrombus formation, on two test materials (acrylate resin and polyethylene) was counted under shear flow conditions of 1s^-1 and 50s^-1. Results showed that there was no difference in the number of adhering platelets to the two material urfaces between the fresh and bank blood under shear flow. However, increase in shear flow decreased the number of adhering platelets. In addition, shear stress changed the rank of the materials. In conclusion, it was suggested that our cone and plate-type rheometer system with human blood from a blood bank is a good alternative to animal experiments for testing and screening the hemocompatibility of materials.