In vitro blood compatibility evaluation method: incubating while rotating hemodialyzers filled with fresh human blood

One of the often-used methods for in vitro evaluation of the blood compatibility of hemodialysis membranes is the circulation of human blood through a miniaturized hemodialyzer. The use of a rather small amount of human blood in its evaluation is one advantage of this method. However, because it is manufactured by a different process than actual ones, a miniaturized hemodialyzer membrane cannot always preserve the properties of actual hemodialyzers. To address this problem, we established a new experimental method that uses a relatively small amount of human blood and actual dialyzers. In this method, a test hemodialyzer and a control hemodialyzer filled with human blood obtained from the same donor is slowly rotated to prevent spontaneous blood cell sedimentation for 4 h at 37 °C. By use of this method, we were able to compare blood compatibility between a polysulfone (PS) membrane and a vitamin E (VE)-bonded PS membrane in terms of their relative antithrombotic, antioxidative, and anti-inflammatory properties. Consistent with many previous reports, the results clearly showed that compared with the PS membrane, VE-bonded PS membrane is more blood compatible. These findings suggest that our method is applicable, at least to in vitro blood compatibility evaluation of PS type dialysis membranes.