Evaluation of Platelet Gel Characteristics Using Thrombin Produced by the Thrombin Processing Device: A Comparative Study

Abstract

Autologous platelet gels can be prepared using the patient's own platelet-rich plasma and thrombin produced by the Thrombin Processing Device (Thermogenesis Corp, Rancho Cordova, CA). As the Thrombin Processing Device thrombin contains a residual amount of ethanol, the purpose of this study was to investigate the effect of the Thrombin Processing Device thrombin on growth factor release from platelet gels, and the effect on cell viability and cell proliferation. Platelet gels were prepared using Thrombin Processing Device-produced human thrombin at platelet-rich plasma to thrombin ratios of 3.3 to 1 and 7 to 1. Commercially available bovine thrombin was used as control. The content of the growth factors, platelet-derived growth factor beta polypeptide, and transforming growth factor beta, were assessed in both the clot and supernatant. The influence of different concentrations of ethanol on cell viability was assessed by flow cytometry and cell proliferation was assessed by (3)H-thymidine incorporation. Using a ratio of 3.3 to 1, the supernatant of the platelet gel produced with Thrombin Processing Device thrombin had a lower growth factor content compared with bovine thrombin but was similar when prepared using a ratio of platelet-rich plasma to thrombin of 7 to 1. Supernatants from the platelet gels did not affect the viability of human macrophage line cells or a fibroblast cell line. When the different platelet gels or their supernatants were tested for their ability to stimulate cell proliferation, similar rates of proliferation were observed. These data suggest that residual ethanol in the Thrombin Processing Device-produced thrombin does not affect any of the tested parameters and has similar characteristics as commercially available bovine thrombin.