The Effects of Chitin/Chitosan on Human Coronary Vascular Smooth Muscle Cells and Endotherium

甲壳素/壳聚糖具有促进植物生长、抗菌、防腐、止血、缝合和人工皮肤等作用。本文研究了甲壳素/壳聚糖对体外培养的人冠状动脉平滑肌细胞迁移、增殖和胶原合成的影响。采用兔球囊导管损伤模型，观察甲壳素/壳聚糖对血管内膜厚度的影响（甲壳质：壳聚糖=20：80,分子量1000- 100万）溶液抑制迁移和增殖（通过3 H-胸苷掺入测定）和胶原蛋白合成（通过3 H-脯氨酸掺入测量）。然而，甲壳素/壳聚糖溶液（甲壳素：壳聚糖=50：50）和壳聚糖低聚物（n<40）没有观察到这些抑制作用。2)ADP刺激的血小板聚集也受到抑制，呈浓度依赖性。3)细胞在甲壳素/壳聚糖凝胶上的贴壁和增殖甲壳素：壳聚糖=20：80的溶液对细胞增殖也有抑制作用;（甲壳质：壳聚糖=20：80）溶解于抗坏血酸中，皮下给予（25 mg/kg）两次（球囊损伤后即刻和2周后）在球囊导管损伤家兔（20 PSI牵拉3次）中的作用。4周后，对损伤的髂动脉进行组织学检查。皮下注射甲壳素溶液后，内膜（内膜+中膜）表面积（25.0 ± 7.4vs16.2 ± 4.9，p<0.01）和内膜/中膜表面积（43.5 ± 6.4vs31.3 ± 9.9，p<0.01）均明显减少。4)在血液样本中未观察到明显的不良反应。结论甲壳素/壳聚糖可有效预防PTCT和血管成形术后再狭窄。

Chitin/chitosan are known to exert promoter action of plant growth, antimicrobial action, antiseptic action, and also used as hemostatic agents, suture materials, and artificial skin, We examined the effects of chitin/chitosan on migration, proliferation of and collagen synthesis by human coronary vascular smooth muscle cells in vitro. We also examined the effects of chitin/chitosan on intimal thickness by using rabbit balloon catheter injury model in vivo.Results 1) Chitin/chitosan solution (chitin : chitosan=20 : 80, molecular weight 1000-one million) solution inhibits migration and proliferation (measured by 3H-thymidine incorporation) of and collagen synthesis (measured by 3H-proline incorporation) by human coronary smooth muscle cells in a concentration-dependent manner. However, these inhibitory effects are not observed by chitin/chitosan solution (chitin : chitosan=50 : 50) and chitosan oligomers (n<40). 2) ADP-stimulated platelets aggregation was also inhibited in a concentration-dependent manner. 3) Attachment and proliferation of the cells cultured on the gel made from chitin/chitosan solution (chitin : chitosan=20 : 80) were also inhibited, 3) Chitin/chitosan solution (chitin : chitosan=20 : 80) resolved in ascorbic acid was given subcutaneously (25mg/kg) twice (immediately after balloon injury, and 2 weeks later) in balloon catheter injury rabbit (three times pull with 20PSI). Four weeks later, injured iliac arteries were examined histologically. The surface area of intima (intima+media) (25.0+/-7.4 vs 16.2+/-4.9, p<0.01) intima/media (43.5+/-6.4 vs 31.3+/-9.9, p<0.01) was significantly reduced by subcutaneous injection of chitin chitosan solution. 4) No obvious adverse effects were observed in blood samples. Conclusion Our data suggest possible usefulness of chitin/chitosan for prevention of restenosis after PTCT as well as after angioplasty.