Histological and immunohistochemical studies of tissue engineered odontogenesis
Histological and immunohistochemical studies of tissue engineered odontogenesis
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DOI：
10.1679/aohc.68.89
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发表时间：
2005-06-01
影响因子：
--
通讯作者：
Ueda, M
中科院分区：
文献类型：
--
作者：
Honda, MJ;Sumita, Y;Ueda, M
最近报道了基于组织工程原理的复杂牙齿结构的成功再生。然而，这种复兴的过程仍然没有得到很好的描述。在这项研究中，我们使用组织化学方法检测组织工程牙齿的再生过程，以确定导致这些工程牙齿结构的细胞类型。将猪第三磨牙牙芽分离成单细胞悬液，种植到可生物降解的聚乙醇酸聚合物支架上。在大鼠宿主的不同生长阶段后，通过组织学和免疫组织化学对标本进行评估。种植后4~6周，首先可见上皮细胞聚集。这些聚集体呈现三种不同的形状：天然牙胚样形状、圆形或双层束。根据牙齿上皮中星状网的结构，圆形和双层集合体可以清楚地分为两种类型：一种是星状网广泛发育的类型，另一种是星状网很少的类型。圆形集合体中的上皮细胞分化为成釉细胞。连续的双层束最终形成上皮鞘，在这些双层束的顶端有明显的牙本质组织。最后，形成釉质覆盖的牙本质和牙骨质覆盖的牙本质，这一过程很可能是由上皮-间充质相互作用所介导的。这些结果表明，这些工程化牙齿的发育与来自未成熟的上皮细胞和间充质细胞的自然成牙过程非常相似。
The successful regeneration of complex tooth structures based on tissue-engineering principles was recently reported. The process of this regeneration, however, remains poorly characterized. In this study, we have used histochemistry to examine the regeneration process of tissue engineered teeth in order to determine the cell types that give rise to these engineered tooth structures. Porcine third molar tooth buds were dissociated into single-cell suspensions and seeded onto a biodegradable polyglycolic acid polymer scaffold. Following varying periods of growth in rat hosts, the specimens were evaluated by histology and immunohistochemistry. Aggregates of epithelial cells were first observed 4-6 weeks after implantation. These aggregates assumed three different shapes: a natural tooth germ-like shape, a circular shape, or a bilayer-bundle. Based on the structure of the stellate reticulum in the dental epithelium, the circular and bilayer-bundle aggregates could be clearly classified into two types: one with extensively developed stellate reticulum, and the other with negligible stellate reticulum. The epithelial cells in the circular aggregates differentiated into ameloblasts. The continuous bilayer bundles eventually formed the epithelial sheath, and dentin tissue was evident at the apex of these bundles. Finally, enamel-covered dentin and cementum-covered dentin formed, a process most likely mediated by epithelial-mesenchymal interaction. These results suggest that the development of these engineered teeth closely parallels that of natural odontogenesis derived from the immature epithelial and mesenchymal cells.