小鼠牙胚发育无血清体外培养模型的建立

Establishment of the developmental model of mouse molar under serum-free condition in vitro

目的 :建立小鼠牙胚发育无血清体外培养模型。方法 :胎龄 17d的Balb/c胎鼠上颌第一磨牙牙胚 ,BGJb无血清半固态培养基中恒温培养 4、6、8～ 16d。终止培养后常规制备石蜡切片 ,HE及vonKossa染色。结果 :初始培养时牙胚处于帽状晚期 ,成釉器分为三层 ,紧邻基底膜的牙乳头细胞排列不规则 ,核多为圆形。体外培养 4～ 6d后 ,牙胚在体外进一步生长。培养 6d后 ,牙尖处成牙本质细胞分化为高柱状 ,并在局部分泌基质。体外培养 8d,牙胚进入钟状晚期 ,有基质带形成。培养 16d后 ,牙冠已基本形成 ,根方出现上皮隔。vonKossa染色结果显示 :培养 10d后 ,牙胚基质带出现阳性着色。结论 :建立了小鼠磨牙发育无血清体外培养模型 ,该模型在体外真实地再现了成牙本质细胞、成釉细胞的分化和基质分泌、矿化等生理过程 。

AIM: To establish developmental model of mouse molar in serum-free condition in ivitro.METHODS: Specimens of the first molar were dissected from 17 th d embryonic Balb/c mice and cultured in the agarose semi-solid medium under serum-free and chemically defined conditions for 4d, 6d, 8～16d,respectively, examined by HE and von Kossa staining finally. RESULTS: At the beginning of culture, explants were at late cap stage. Enamel organ has three distinct compartments and papilla cells arranged randomly underneath the base membrane. After 6 days culture, preodontoblasts, which located at the tip of the cusp,differentiated into tall columnar odontobasts and began to secret matrix locally. After 8 days' cultured strip of matrix was secreted, explants were at late bell stage then. However, the first positive staining of von kossa appeared after cultured 10 days. After 16 days culture, crowns were well formed. In addition, roots began to develop. CONCLUSION: We established a developmental model of mouse molar in serum-free condition in vitro which imitated physiological process of matrix' secretion and mineralization , as well as differentiation of odontoblasts and ameloblasts.