Mimicking the Dentin-Pulp Complex In-Vitro

描述(由申请人提供)：该项目试图使用微细加工和牙髓干细胞(DPSC)在体外创建牙本质-牙髓复合体。牙本质牙髓界面的特征是具有独特形态的特殊细胞衬里，这些细胞产生胶原牙本质基质并控制其矿化。高度极化的成牙本质细胞直径在5到10？m之间，沿着牙髓壁紧密堆积。它们的独特特征是成牙本质细胞的突起，沿着小管延伸到矿化的牙本质中，深达10毫米。在牙齿的整个生命周期中，细胞都固定在这个位置。因此，这些细胞可以存活几十年，只有通过产生额外的牙本质基质(修复性牙本质)来应对外界的伤害。周围的牙本质髓含有祖细胞，当与上皮干细胞或成釉细胞样干细胞植入免疫受损的小鼠体内时，这些祖细胞可以分化为成牙本质细胞，并产生牙本质基质或形成牙本质冠。这项申请建议使用组织工程学方法在体外重建这种高度组织的细胞排列。与Tejal Desai博士的生物工程实验室和加州大学伯克利分校的微制造设施合作，将产生微图案聚合物支架，使细胞能够在精确的位置定位。在我们的设计中，这些位置将与一个开放的圆柱孔对齐，允许在每个孔的顶部放置一个细胞。趋化方法将被用来鼓励成牙本质细胞突起进入毛孔，导致极化细胞的细胞形态，类似于牙本质-牙髓界面。这些研究将产生一种独特的结构来研究基因在体外的表达和细胞相互作用，并提高我们对牙齿发育的理解。此外，这种预先组装的牙齿组织模拟将推动目前的牙齿再生和牙髓振兴的方法。 与公共健康相关：该项目建议制造微图案膜，在体外将牙髓干细胞定位在类似于人类牙齿牙本质-牙髓界面的配置中。细胞组织工程化构建将促进未来对上皮/间充质相互作用的分子生物学研究，并进一步加强牙科组织工程化的方法。

DESCRIPTION (provided by applicant): This projects attempts to create the dentin-pulp complex in-vitro using microfabrication and dental pulp stem cells (DPSC). The dentin pulp interface is characterized by a lining of specialized cells of unique morphology that produce the collagenous dentin matrix and control its mineralization. Highly polarized odontoblasts with diameters of 5 to 10 ¿m are tightly packed along the pulpal wall. Their unique feature is the odontoblastic process that extends up to 10 mm deep along tubules into the mineralized dentin. The cells are anchored in this position for the lifetime of the tooth. Hence these cells can live fr decades and only respond to external insult by producing additional dentin matrix (reparative dentin). The surrounding dentin pulp contains progenitor cells that can differentiate into odontoblast cells and produce dentin matrix or form a dentin crown when implanted with epithelial or ameloblast-like stem cells into an immunocompromised mouse. This application proposes to reconstitute this highly organized arrangement of cells in-vitro using tissue engineering approaches. In collaboration with the bioengineering laboratory of Dr. Tejal Desai and the microfabrication facilities at the University of California at Berkeley, micropatterned polymer scaffolds will be generated that permit the positioning of cells in precise locations. In our design these locations will be aligned with an open cylindrical pore allowing for one cell being positioned on top of each pore. Chemotactic approaches will be used to encourage protrusion of odontoblastic processes into the pores resulting in a cellular configuration of polarized cells that is comparable to the dentin-pulp interface. These studies will produce a unique construct to investigate gene expression and cellular interactions in-vitro and improve our understanding of tooth development. Furthermore such pre-assembled mimicries of dental tissue will advance current approaches towards tooth regeneration and pulp revitalization. PUBLIC HEALTH RELEVANCE: This project proposes to fabricate micropatterned membranes that will position dental pulp stem cells in-vitro in a configuration similar to the dentin-pulp interface in human teeth. The cell tissue engineered construct will facilitate future molecular biology studies on epithelium/mesenchyme interactions as well further enhance approaches towards engineering of dental tissues.