Dentine regeneration by differentiation of pulp cells and bone marrow cells to odontoblasts

骨髓干细胞取自大鼠股骨干。这些细胞在添加了地塞米松、抗坏血酸-2磷酸和β-甘油磷酸的膜基质中培养。培养2周后，培养皿中有钙沉积，提示骨髓干细胞向成骨细胞分化，并对大鼠切牙牙髓细胞进行培养。牙髓细胞中存在极少量的硬组织形成细胞。牙髓细胞内有少量贴壁细胞。牙髓细胞中有少量贴壁细胞，说明牙髓细胞培养困难。三维培养被认为适合牙髓细胞。地塞米松作用于骨髓干细胞，细胞分化形成硬组织。但地塞米松对牙髓硬组织形成细胞的分化和增殖无影响。有人认为，DIF…的一种新的补充牙髓细胞需要更多的硬组织形成细胞中的发酵剂。骨髓干细胞应该分化为硬组织形成细胞，如成骨细胞。牙髓细胞也会分化为成牙本质细胞。多孔羟基磷灰石作为细胞分化的支架。将骨髓干细胞或牙髓细胞分别接种于羟基磷灰石支架的孔隙中。将支架植入大鼠背部皮下组织。在本实验中，由于没有从大鼠切牙获得足够数量的牙髓细胞，所以种植少量细胞的支架孔内没有形成硬组织。骨髓干细胞在支架的毛孔中形成新骨。将透明质酸或层粘连蛋白应用于支架的孔内，可诱导1/10的细胞在多个孔内成骨。透明质酸或层粘连蛋白的应用可诱导少数细胞在一个孔内形成多个骨组织。结果表明，由于补充剂的作用，少数细胞也可在支架内形成硬组织。较少

Bone marrow stem cells were obtained from the bone shaft of rat femora. These cells were cultured in MEM which was supplemented with dexamethasone, ascorbic acid-2 phosphoric acid and β-glycerophosphate. After 2 weeks of culture, the existence of calcium deposition in culture dish indicated differentiation to osteoblastic cells of bone marrow stem cells.Pulp cells obtained from rat incisor were also cultured. Extremely a small number of hard tissue formation cells existed in the pulp cells. A small number of adherent cells were contained in the pulp cells. A small number of adherent cells in the pulp cells shows the difficulty of pulp cell culture. Three-dimensional culture was thought to be suitable for the pulp cells. Dexamethasone influences to bone marrow stem cells, and the cells differentiate to form hard tissue. However, dexamethasone showed no influence in differentiation and proliferation of pulp cells for hard tissue formation. It was considered that a novel supplement to dif … More ferentiate in hard tissue formation cells would be required for pulp cells.Bone marrow stem cells should differentiate in hard tissue formation cells such as osteoblastic cells. Pulp cells will also differentiate to odontoblasts. Porous hydroxyapatite was used as a scaffold for these cells to differentiate. Bone marrow stem cells or pulp cells were respectively seeded in the pores of hydroxyapatite scaffolds. The scaffolds were implanted in the dorsal subcutaneous tissue of rats. The possibilities of cell differentiation and hard tissue formation in the pores were examined.In this experiment, because sufficient number of pulp cells was not obtained from rat incisors, hard tissue was not formed in the pores of scaffold seeded small number of the cells. Bone marrow stem cells form new bone in the pores of scaffold. Application of hyaluronic acid or laminin to pores of scaffold induced bone formation in many pores by 1/10 number of cells.Hyaluronic acid or application of laminin induced many bone formation in a pore by a small number of cell The result indicates that small number of cells may also form hard tissue in the scaffold because of contribution of the supplements. Less