[Effects of multiwall carbon nano-onions on platelet aggregation and hemostatic function].

OBJECTIVE: To observe the effects of multiwall carbon nano-onions (MWCNOs) on platelet aggregation and hemostatic function. METHODS: The platelet aggregation was determined with Born's method at different concentration of MWCNOs (0, 0.2, 2.0, 20.0 microg/ml) in vitro. Twenty male SD rats were randomly divided into 4 groups which were exposed to 0, 2, 4 and 8 mg/kg MWCNOs, respectively. Then platelet count, platelet aggregation, activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), bleeding time (BT) and platelet count (PC) were measured at 12 h after receiving tail intravenous injection of MWCNOs. The effects of MWCNOs (4 mg/kg) on platelet aggregation and platelet count at different time points were observed. RESULTS: In vitro, MWCNOs exhibited the potent inhibitory effects on rat platelet aggregation caused by ADP in a concentration-dependent manner. The platelet aggregation in the highest dosage of 20.0 microg/ml group was 50.0% +/- 6.9% which was significantly lower than that (73.2% +/- 4.3%) in control group (P<0.01). In vivo, the highest inhibitory was up to 20.4%, but there was no significant difference, as compared with control group. MWCNOs did not affect the APTT, PT, TT, BT and PC. CONCLUSION: Under this experimental condition, MWCNOs might inhibit platelet aggregation but not affect hemostatic function.