去细胞组织工程同种心脏瓣膜的生物学特征

The biological properties of decellularized human tissue-engineering aortic valves conduits

目的 构建去细胞组织工程同种心脏瓣膜 ,对比研究同种心脏瓣膜去细胞前后的生物学特征。方法 取液氮保存的人同种主动脉带瓣管道 ,采用低渗液 -去污剂 ( 1%DOA) -核酸酶去细胞法 ,测定去细胞前后组织学、组织厚度、组织含水量、热皱缩温度、组织基因组DNA含量、胶原蛋白含量。结果 同种心脏瓣膜、管壁及肌肉组织中去除所有细胞成分 ,保留了完整的细胞外基质。与去细胞前相比 ,管壁组织的含水量 [( 75 4 4± 1 84 ) %对 ( 82 0 5± 0 71) % ,P <0 0 5 ]明显增加 ,组织基因组DNA含量显著下降(瓣叶下降 91 14 %、管壁下降 91 5 3% ) ;瓣叶组织含水量、组织厚度、热皱缩温度及组织胶原蛋白含量差别无显著性。结论 低渗液 -去污剂 ( 1%DOA) -核酸酶去细胞法方便有效 ,去细胞的同种组织工程心脏瓣膜生物学特性稳定 ,符合机体要求 ;

Objective: To study the biological properties of a decellular human tissue engineering homograft aortic valves conduits. Methods: (1) Human homograft aortic valves conduits were treated with the pH 8 0 hypotonic tris buffer for 12h. (2) Then with pH 8 0 isotonic buffer added with the 1% DOA (deoxycholic acid) for 24h. (3) At last, a pH 7 6 isotonic buffer with the DNAase 200μg/ml, NAase 20 μg/ml was applied. The histology, water content, thickness, denaturation temperature, DNA content, collagen contents were examined. Results: The valves, the wall and the muscle layer of the human homograft aortic valves conduits were decellulared completely compared with the standard crypreserved human homograft aortic valves. Water content in the decellular aortic wall was increased significantly (75 44±1 84 vs. 82 05±0 71,P<0 05). DNA content of the valve was decreased by 91 14% and 91 53% of the wall. Denaturation temperature, collagen contents and thickness of the decellularized human homograft aortic valves had no significant differences. Conclusion: The decellularized method applied in this study could be effective according to the data. Meanwhile, the biological properties of the decellularized human homograft aortic valves were shown relatively stable. These valves might be used as an ideal valve for patients or as a homograft stent for tissue engineering valve by host recellularization of the fibrous matrix.