OBJECTIVETo observe the effects of multi-walled carbon nano-onions (MWCNOs) on platelet adhesion and experimental thrombosis in rats.

METHODSExperimental rats were randomly divided into sham operation group, solvent group, and MWCNO group, each including 6 ∼ 9 rats. An inverted fluorescence microscope and a flow chamber were used to observe the effects of 20 g/ml MWCNOs on platelet adhesion at shear rates of 500 s(-1) and 1000 s(-1); the experiment was repeated at least three times in each group. A rat model of carotid artery thrombosis was induced by 25% FeCl3, and the effects of 2 mg/kg MWCNOs on the blood flow and wet weight of thrombus per millimeter in the model were observed.

RESULTSWhen the shear rate was 500 s(-1), the MWCNO group showed a significantly smaller number of adhering platelets than the solvent group (58.3 ± 16.1 platelets/0.01 mm(2) vs 190.1 ± 36.0 platelets/0.01 mm(2)), but the inhibitory effect of MWCNOs on platelet adhesion disappeared as the shear rate increased to 1000 s(-1). The wet weights of thrombus per millimeter at 0 h after injection of a solvent or MWCNOs via the caudal vein were 0.83 ± 0.12 mg/mm in the solvent group and 0.97 ± 0.11 mg/mm in the MWCNO group, and the wet weights of thrombus per millimeter at 12 h after injection were 0.89 ± 0.12 mg/mm in the solvent group and 1.01 ± 0.15 mg/mm in the MWCNO group, exhibiting no significant differences between the two groups (P > 0.05). There were also no significant differences between the two groups in terms of blood flow at 0 h and 12 h after injection (P > 0.05).

CONCLUSIONMWCNOs have inhibitory effect on platelet adhesion in vitro, but the injection of MWCNOs via the caudal vein has no effects on the blood flow and wet weight of thrombus per millimeter in experimental thrombosis in rats.