间充质干细胞构建组织工程瓣膜的生物力学性能研究

Biomechanical Properties of Tissue Engineered Heart Valve Using Mesenchymal Stem Cells as Seed Cells

目的采用碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)联合间充质干细胞(mesenchy-mal stemcells,MSCs)构建组织工程心脏瓣膜(tissue engineered heart valve,TEHV),并对其生物力学性能进行研究。方法分离培养大鼠MSCs,进行细胞鉴定后种植于去细胞瓣叶支架上。将瓣叶置于含5 ng/ml bFGF的培养液中,分别培养7 d和14 d作为实验组A和实验组B。实验组C除培养液中不添加bFGF外,其余同实验组B。对照组为大鼠肌成纤维细胞构建的TEHV。对各组TEHV进行形态学观察,生化检测和生物力学测试。结果MSCs表达CD29(94.82%)和CD44(93.59%)。各组TEHV具有相似的形态结构,DNA和羟脯氨酸含量、最大负荷、最大应力、最大应变和弹性模量的差异无统计学意义(P>0.05)。结论采用MSCs和肌成纤维细胞构建的TEHV具有相同的生物力学性能,而采用bFGF联合MSCs体外构建TEHV能在更短的时间内获得相同的生物力学性能。

Objective Tissue engineered heart valve（TEHV） was constructed using bFGF and mesenchymal stem cells （MSCs）. And its biomechanical properties were investigated. Methods MSCs were isolated and cultured. After cell identification,MSCs were seeded onto decellularized aortic valve leaflet scaffold to constuct TEHV in each group. TEHV were cutlured with DMEM containing 5 ng/ml bFGF in vitro for 7 d in group A or 14 d in group B. In group C,TEHV was cutlured with DMEM only for 14 d. In control group,TEHV were constructed using myofibroblasts as seed cells. TEHV in each group was examined morphologically,biochemically and biomeehanically. Results MSCs expressed CD29（94.82%） and CIM4（93. 59%）. TEHV in each group showed simliar morphologcical structure. And the differences of DNA and hydroxyproline contents, Max-load, Maxstress,elastic modulus and Max-strain between groups had no statistically significant difference（P〉0.05）. Conclusion The biomechanical properties of TEHV using MSCs as seed cells were equal to TEHV using myofibroblast as seed cells. However, construction of TEHV using bFGF and MSCs can shorten the time of construction in vitro with the same biomechanical properties.