Schmidt Dörthe, Achermann Josef, Odermatt Bernhard, Breymann Christian, Mol Anita, Genoni Michele, Zund Gregor, Hoerstrup Simon P
Clinic for Cardiovascular Surgery and Department of Surgical Research, University and University Hospital Zurich, Raemistrasse 100, CH 8091 Zurich, Switzerland.
Circulation. 2007 Sep 11;116(11 Suppl):I64-70. doi: 10.1161/CIRCULATIONAHA.106.681494.
A novel concept providing prenatally tissue engineered human autologous heart valves based on routinely obtained fetal amniotic fluid progenitors as single cell source is introduced.
Fetal human amniotic progenitors were isolated from routinely sampled amniotic fluid and sorted using CD133 magnetic beads. After expansion and differentiation, cell phenotypes of CD133- and CD133+ cells were analyzed by immunohistochemistry and flowcytometry. After characterization, CD133- derived cells were seeded onto heart valve leaflet scaffolds (n=18) fabricated from rapidly biodegradable polymers, conditioned in a pulse duplicator system, and subsequently coated with CD133+ derived cells. After in vitro maturation, opening and closing behavior of leaflets was investigated. Neo-tissues were analyzed by histology, immunohistochemistry, and scanning electron microscopy (SEM). Extracellular matrix (ECM) elements and cell numbers were quantified biochemically. Mechanical properties were assessed by tensile testing. CD133- derived cells demonstrated characteristics of mesenchymal progenitors expressing CD44 and CD105. Differentiated CD133+ cells showed features of functional endothelial cells by eNOS and CD141 expression. Engineered heart valve leaflets demonstrated endothelialized tissue formation with production of ECM elements (GAG 80%, HYP 5%, cell number 100% of native values). SEM showed intact endothelial surfaces. Opening and closing behavior was sufficient under half of systemic conditions.
The use of amniotic fluid as single cell source is a promising low-risk approach enabling the prenatal fabrication of heart valves ready to use at birth. These living replacements with the potential of growth, remodeling, and regeneration may realize the early repair of congenital malformations.
引入了一种新的概念，即基于常规获取的胎儿羊水祖细胞作为单一细胞来源，在产前构建组织工程化人自体心脏瓣膜。
从常规采集的羊水中分离出人胎儿羊水祖细胞，并用CD133磁珠进行分选。在扩增和分化后，通过免疫组织化学和流式细胞术分析CD133 - 和CD133 + 细胞的细胞表型。在进行表征后，将CD133 - 衍生的细胞接种到由快速可生物降解聚合物制成的心脏瓣膜小叶支架（n = 18）上，在脉冲复制器系统中进行处理，随后用CD133 + 衍生的细胞包被。体外成熟后，研究小叶的开闭行为。通过组织学、免疫组织化学和扫描电子显微镜（SEM）对新组织进行分析。通过生化方法对细胞外基质（ECM）成分和细胞数量进行定量。通过拉伸试验评估力学性能。CD133 - 衍生的细胞表现出表达CD44和CD105的间充质祖细胞特征。分化的CD133 + 细胞通过eNOS和CD141表达显示出功能性内皮细胞的特征。工程化心脏瓣膜小叶显示出内皮化组织形成，并产生ECM成分（糖胺聚糖80%，羟脯氨酸5%，细胞数量为天然值的100%）。SEM显示内皮表面完整。在一半的全身条件下，开闭行为良好。
使用羊水作为单一细胞来源是一种有前景的低风险方法，能够在产前制造出生时即可使用的心脏瓣膜。这些具有生长、重塑和再生潜力的活体替代物可能实现先天性畸形的早期修复。
