Bone reconstruction by osteoblasts conjugated implants in aged human

(1)骨髓细胞中含有具有多分化能力的干细胞。这些细胞在常规培养皿中分化成成纤维细胞。经胶原凝胶培养后分化为成骨细胞，形成钙化结节。(2)对钙化结节进行了电镜观察，识别出基质囊泡样元素。在胶原纤维上沉淀出针状晶体，x射线显微分析仪鉴定出钙和磷酸盐，推测针状晶体为羟基磷灰石。(3)这些结果表明，钙化结节的矿化过程与人体相似，骨髓细胞形成的钙化结节与骨骼相同。(4)胶原蛋白的诱导活性对I型胶原蛋白和凝胶具有特异性。将I型胶原干燥后，在膜型胶原上培养骨髓细胞，胶原对骨髓细胞没有诱导活性。(5)这些结果表明胶原蛋白的特性对诱导骨髓细胞的活性至关重要。

(1) Bone marrow cells contained stem cells that possess the potency of multi-differentiation. These cells differentiate into fibrolasts when they were cultured on conventional culture dishes.When they were cultured on collagen gel, they differentiated into osteoblasts and formed calcified nodules.(2) The calcified nodules were investigated by electron- micro-scopic observation, and matrix vesicle-like elements were recognized. Furthemore, needle-like crystals were precipitated on collagen fibers, In these crystals, calcium and phosphate was identified by x-ray microanalyzer, and neelde-like crystals were suspected to be hydroxyapatite.(3) These findings indicated that the process of mineralization in calcified nodules is similar to that of body, and the calcified nodules formed by bone marrow cells are same with bone.(4) The inductive activity of collagen is specific for type I collagen and the gel. If type I collagen was dried and bone marrow cells were cultured on membrane-type collagen, collagen did not show inductive activity against bone marrow cells.(5) These results indicate that features of collagen is crucial for the inductive activity against bone marrow cells.