载血管内皮生长因子组织工程血管缓释模型构建

Construction of vascular sustained release model of vascular endothelial growth factor

目的构建能缓释血管内皮生长因子（VEGF）的组织工程小口径血管模型，观察其缓释微球性能及血管支架性能，为后期动物实验提供材料和理论基础。方法采用脱细胞试剂对绵羊颈动脉进行处理，观察其脱细胞情况及支架性能。制备载有VEGF的缓释微球，检测微球粒径、包封率、载药量及测出缓释曲线。采用冷冻干燥技术将缓释微球与血管支架有效结合。将大鼠血管内皮细胞种植于组织工程血管缓释模型管腔内，观察内皮生长情况。结果羊颈动脉经处理后能保持血管支架原有性能。缓释微球平均粒径（9．8±6．0）um，在20天内能缓慢释放，释放率达70％。缓释微球能与组织工程血管有效紧密结合。大鼠血管内皮细胞能够在血管支架内表面生长。结论采用TritonX．100、DNA／RNA核酶作脱细胞试剂，血管支架性能良好；用PLGA制成的缓释微球有良好的缓释性能，冷冻干燥技术能使缓释微球与血管支架紧密结合，构建合适的组织工程小口径血管缓释模型。

Objective To construct a model of small caliber vascular endothelial growth factor（VEGF） in tissue engi- neering, to investigate the performance of the sustained-release microspheres and vascular stent, and to provide materials and＇ theoretical basis for animal experiment. Methods The sheep carotid arteries were treated with a cellular reagents, the cellular conditions and the stent properties were observed. Preparation of sustained release microspheres containing VEGF, particle size, encapsulation efficiency, drug loading and release curve were measured. The effective combination of the slow release mi- crosphere and the vascular stent was used in the freeze drying technology. The rat vascular endothelial cells grown in tissue en- gineered blood vessel model release lumen, observe the growth of endothelial ceils. Results After the treatment, the original performance of the vascular stent can be maintained. The average particle size of the microspheres was （9.8 ± 6.0） μm, which could be released slowly in 20 days, and the release rate was 70%. Microspheres can effectively with the tissue engineering blood vessel tight binding. Rat vascular endothelial ceils can grow in the vascular stent surface. Conclusion Using Triton X- 100, DNA/RNA ribozyme for acellular reagent, stent performance is good. PLGA microspheres have good sustained release performance, and constructing appropriate tissue engineered small caliber vascular release model by using freeze drying technol- ogy can make the stent compact structure.