In vitro hemocompatibility evaluation of poly (4-hydroxybutyrate) scaffold.

The biosynthetic thermoplastic poly-4-hydroxybutyrate (P4HB) possesses favorable tensile strength and elongation performance and has been studied as a new implantable polymer material for medical uses. However, its hemocompatibility has not been tested to confirm its applicability to tissue engineering. In this study, a series of experiments was performed that included erythrocyte hemolysis tests, dynamic blood coagulation tests, platelet adhesion tests, effects on blood coagulation, Wright staining, and adsorption of erythrocytes, leukocytes, platelets, and plasma proteins. The results were compared with control tests on polyvinyl chloride (PVC), a biomaterial in current use, to evaluate the relative in vitro hemocompatibility of P4HB. The degree of hemolysis in the presence of P4HB was 1.9 ± 0.2%. The absorbance-time curve for blood clotting declined slowly and smoothly. There were no differences in the test values of Factor XII, activated partial thromboplastin time (APTT), or fibrin degradation products (FDPs) among whole blood samples exposed to P4HB or PVC and the blank control groups (P > .05). Adsorption of platelets and globulin was similar in samples exposed to P4HB and PVC (P > .05), but the adsorption of erythrocytes, leukocytes, and albumin to P4HB was higher (P < .05). In conclusion, P4HB compares favorably with PVC in terms of blood compatibility, except for a higher affinity for erythrocytes and leukocytes. The findings indicate that P4HB, an alternate scaffolding material with advantageous properties, is generally acceptable for bioengineering use.