Abstract:

BACKGROUND: In according to ISO-10993-4 and GB/T 16886.4, the in vitro hemo-compatibility evaluation on biomaterials includes thrombosis, coagulation factors, platelets and platelet functions, hematology and complement system. However, in the case of China, the in vitro hemo-compatibility evaluations were performed only thrombosis, coagulation factors and platelet attachment, the investigation on evaluation of platelet and complement activations is less reported.
OBJECTIVE: To evaluate the effect of polyethylene, polyvinyl chloride and polymethylvinylsiloxane tubes on platelet activation, and establish a useful method to evaluate the effect of tubular materials on platelet activation.
METHODS: Tubes of polyethylene, polyvinyl chlorid and silastic were established by 3.7 mm inner diameter, 3.5 mm external diameter, and 35 cm length, respectively. 1 mL blood was injected into the tube of polyethylene, polyvinyl chlorid and silastic, respectively. The tubes were connected using a two-way tube, shaken at 140 r/min by 30° sloping for 3.5 hours at 37 ℃. Radioimmunoassay was employed to detect α-granules protein level of platelet poor plasma, while flow cytometry was used to detect the percentage of positive platelet of α-granules protein and that of activated gpⅡb/Ⅲa composite.
RESULTS AND CONCLUSION: Radioimmunoassay showed that α-granules protein level of platelet poor plasma in the polyethylene and polyvinyl chlorid tubes was significantly greater than that in the silastic tube (P < 0.05). There were no significant differences in α-granules protein between polyethylene and polyvinyl chlorid (P > 0.05). Flow cytometry indicated that percentage of positive platelet of α-granules protein in the polyethylene and polyvinyl chlorid tubes was significantly greater than that in the silastic tube (P < 0.05); the percentage in the polyethylene tube was significantly greater than that in the polyvinyl chlorid tube (P < 0.05). There was no significant differences in the percentage of positive platelet of activated gpⅡb/Ⅲa composite between the three materials (P > 0.05). A useful blood-material contact model was established, and it was considered that α-granules protein is an available parameter for evaluating platelet activation. The percentage of positive platelet of α-granules protein determined by flow cytometry was a more sensitive parameter for evaluating platelet activation.