[Inhibition of intimal proliferation after vein grafting by chitosan nanoparticle with proliferation cell nuclear antigen-antisense oligo deoxy nucleotides].

OBJECTIVE

To investigate an inhibitive effect of the chitosan nanoparticles with the proliferation cell nuclear antigen (PCNA)-antisense oligo deoxy nucleotides (ASODN) on the intimal cell proliferation after the vein grafting.

METHODS

Fifty-four male SD rats, weighing 450-600 g, were randomly divided in the experimental group and the control group of 27 rats each. In the experimental group, the chitosan nanoparticles with PCNA-ASODN were infused into the anastomosis segment of the right jugular artery and vein; then, the anastomosis segment was transplanted to the jugular artery on the same side. The rats in the control group were infused with normal saline by the same procedures. There were 24 rats in each group which used to experiment. The hemodynamic data were obtained from the Doppler ultrasound examinations at 1, 2, 3 and 4 weeks. The specimens were taken. Immunohistochemistry, Western-blot, and blood-vessel-wall histopathology were performed at the different week points.

RESULTS

There was no significant difference in the thrombogenesis rate between the experimental group and the control group (3/27 vs. 3/27, P > 0.05). During the 4-week observation, PCNA Western-blot showed that the PCNA level was lower in the grafted vein and the anastomosis segment in the experimental group than in the control group. The indexes of the PCNA-postive proliferating cells in the intimal area (0.13% +/- 0.11%, 0.79% +/- 0.28%, 0.45% +/- 0.29%, 0.43% +/- 0.25%) and the medial area (1.90% +/- 0.84%, 2.11% +/- 0.98%, 2.48% +/- 0.77%, 2.17% +/- 0.36%) were significantly decreased at 1, 2, 3 and 4 weeks in the experimental group when compared with those in the control group (P < 0.05). The lumen areas in the grafted vein (88.71 +/- 16.96, 95.98 +/- 21.44, 88.48 +/- 32.81, 97.86 +/- 34. 11 microm2) and the anastomosis segment (41.49 +/- 3.34, 45.15 +/- 11.65, 46.27 +/- 8.90, 51.62 +/- 8.85 microm2) were significantly greater in the experimental group than in the control group (P < 0.05). The ratios of the initmal area to the medial area in the grafted vein (22.73% +/- 3.11%, 32.40% +/- 4.55%, 45.14% +/- 3.19%, 45.70% +/- 5.01%) and the anastomsis segment (41.49% +/- 3.34%, 45.15% +/- 11.65%, 46.27% +/- 8.90%, 51.62% +/- 8.85%) were significantly smaller in the experimental group than in the control group (P < 0.05). The maximum velocities (Vmax) of the blood flow in the grafted vein and the anastomsis segment were almost the same in the two groups at 1 week, but had different changes at the next 3 week-points. In the control group, the Vmax of the blood flow gradually increased and at 3 weeks it reached the peak point; however, at 4 weeks it decreased. In the experimental group, the Vmax of the blood flow gradually decreased, and at 3 weeks it decreased to the lowest point; however, at 4 weeks it increased. So, at 4 weeks the Vmax of the blood flow in the grafted vein and the anastomsis segment was almost the same in the two groups. There was no significant difference in the Vmax of the blood flow between the two groups (P > 0.05), but in the same group there was a significant difference at the different time points.

CONCLUSION

The chitosan nanoparticles with PCNA-ASODN can effectively inhibit the intimal cell proliferation after the grafting of the blood vessel, so that the neointimal thickening can be prevented.