去细胞组织工程同种心脏瓣膜的生物力学研究

Study on the biomechanical properties of decellular human tissue-engineering aortic valve conduits

目的 观察去细胞组织工程同种心脏瓣膜的生物力学特性。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%去氧胆酸 ) 核酸酶法去除了同种心脏瓣膜组织中所有的细胞成分 ,组织基因组DNA含量下降 91% ,保留了完整的细胞外基质。测定去细胞前后组织厚度、组织含水量、热皱缩温度、应力应变曲线、破坏强度及组织伸长比。结果 与去细胞前相比 ,只有管壁组织的含水量去细胞前与去细胞后比较明显增加 (P <0 .0 1) ,瓣叶组织含水量、组织厚度、热皱缩温度、应力应变曲线、破坏强度及组织伸长比差异无显著性 (P >0 .0 5 )。结论 去细胞组织工程同种心脏瓣膜的生物力学特性稳定 ,符合机体的要求 ,且为受体细胞化组织工程心脏瓣膜的研制提供了可靠的天然的纤维支架材料。

Objective To study the biomechanical properties of the decellular human homograft aortic valve conduits.Methods The human homograft aortic valve conduits were treated with hypotonic tris buffer (pH 8.0) for 12 h;then isotonic buffer (pH 8.0) with 1% DOA for 24 h;finally isotonic buffer (pH 7.6) with DNAase 200 mg/L,RNAase 20 mg/L.The valves,wall and muscle were decellulared completely,and DNA content was decreased by 91%.The water content,thinkness,denaturation temperature,stress-strain,destroying stress were examined.Results Compared with that before the cell removal,only water content (%) in the decellular aortic wall was increased significantly (75.44±1.84 vs 82.05±0.71,t=8.214,P<0.01),but there was no significant difference in denaturation temperature,stress-strain,destroying stress ub the decellular human homograft aortic valve conduits.(P>0.05).Conclusion The decellular human homograft aortic valve conduits have stable biomechanical properties and can be used as an ideal valve for patients or as a homograft stent for developing the tissue engineering valve by host recellularization of the fibrous matrix.