Cell-based scaffold-less three-dimensional construct, a model for dentinogenesis

描述（由申请人提供）：据估计，西方国家85%的成年人接受过牙科治疗，到50岁时，成年人平均失去了12颗牙齿。人们正在设计方法来诱导牙本质修复和再生，最近的研究工作是针对组织工程牙齿进行牙齿替代。为了成功地诱导牙本质再生或在体外制造牙齿，需要对所涉及的细胞有更好的了解。该项目的目标是创建一个相关的模型来研究牙本质的体外发生，假设通过允许牙髓干细胞在体外产生自己的3D结构，我们将为牙本质微环境和牙本质基质组装的体外研究创建一个相关的模型系统。干细胞存在于牙髓中，可以分化成成牙本质细胞进行牙本质修复。在原位，成牙细胞存在于三维（3D）结构中，它们分泌和重塑自己。因此，用单层牙髓细胞或人工衍生支架进行的研究不能模拟这些细胞的真实微环境。最近的文献报道显示骨髓基质细胞能够合成和重塑其自身的基质，从而形成圆柱形的骨样结构。这些结构仅由骨髓基质细胞及其新生成的自体细胞外基质组成。该技术将用于指导牙髓细胞在体外产生类似的无支架3D结构。这些结构的分子和结构特性将被研究，并与骨髓基质细胞产生的分子和结构特性进行比较。骨髓基质细胞和牙髓细胞形成的工程组织将被皮下植入免疫受损小鼠体内，研究体内环境的影响，并进一步验证类牙本质结构的产生。

DESCRIPTION (provided by applicant): It is estimated that 85% of adults in Western countries have endured dental treatment and by the age of 50 the average adult has lost 12 teeth. Methods are being designed to induce dentin repair and regeneration and more recent research efforts are targeted toward tissue engineering teeth for tooth replacement. In order to successfully induce dentin regeneration or create a tooth in vitro a better understanding of the cells involved needs to be acquired. The goal of this project is to create a relevant model to study dentinogenesis in vitro with the hypothesis that by allowing dental pulp stem cells to generate their own 3D structure in vitro we will create a relevant model system for in vitro studies of the odontoblastic microenvironment and dentin matrix assembly. Stem cells reside in dental pulp that can differentiate to odontoblasts for dentin repair. In situ, odontoblasts reside in three dimensional (3D) structures that they secrete and remodel themselves. Therefore, studies performed with dental pulp cells in a monolayer or with artificially derived scaffolding do not mimic the true microenvironment of these cells. Recent reports in the literature have shown the ability for bone marrow stromal cells to synthesize and remodel their own matrix to create cylindrical bone-like construct. These constructs only consist of the bone marrow stromal cells and their newly made autogenous extracellular matrix. This technology will be utilized to direct the dental pulp cells to create similar scaffold less 3D constructs in vitro. The molecular and structural properties of these constructs will be studied and compared to those created by bone marrow stromal cells. The engineered tissues formed by bone marrow stromal cells and dental pulp cells will then be subcutaneously implanted into immuno-compromised mice to study the effects of the in vivo environment and further verify the creation of dentin- like construct. Public Health Relevance: It is estimated that 85% of adults in Western countries have endured dental treatment and by the age of 50 the average adult has lost 12 teeth. Methods are being designed to induce dentin repair and regeneration and more recent research efforts are targeted toward tissue engineering teeth for tooth replacement. In order to successfully induce dentin regeneration or create a tooth in vitro a better understanding of the cells involved needs to be acquired.