注射性组织工程牙胚的构建及成牙能力研究

Construction and Odontogenic Potential of Injectable Tissue-engineered Tooth Germ

目的:探索采用大鼠牙胚细胞构建可注射组织工程牙齿的可行性及在体内肾被膜移植的成牙能力研究。方法:采用出生后4d SD仔鼠磨牙牙胚细胞,培养传代后将牙胚细胞与牛真皮基质蛋白溶液混合构建组织工程牙胚,利用注射器植入SD大鼠肾被膜下,2wk后取材,HE染色观察移植物中的组织成熟情况,Masson’s三色法观察组织工程牙胚的成牙能力。结果:组织工程牙胚移植后2wk可在肾被膜下形成乳白色矿化组织,HE染色上皮细胞和间充质细胞进行重组,形成典型的牙髓牙本质复合体样组织和釉质样结构,Masson’s三色法可见绿色矿化基质形成并包绕牙乳头样组织。结论:牙胚细胞仍保留了牙齿发育的位置信息,采用牛真皮基质蛋白溶液作为组织工程支架有助于牙胚细胞相互作用并重新排列,构建的组织工程牙胚具有进一步成熟、矿化并形成牙齿的潜能。

Objective： To evaluate the feasibility of injectable tissue-engineering tooth constructed with tooth germ cells and the odontogenic potential during implanted into renal capsule. Methods： Tooth germ cells from 4 days postnatal （dpn） SD rats were derived and cultured. After passage, the ceils were mixed with the solution of dermal matrix from calf to construct the tissue-engineered teeth, and then, implanted into renal capsule with injector, Reconstructed germs were harvested and analysed with HE staining and Masson＇s staining to identify the odontogenic potential. Results： White mineralized tissues were found under the renal capsule 14 days after injection. The development of distinctive pulp-dentin complex and enamel like structures were observed by HE staining. The green mineralized matrix around the dental papilla was further identified with Masson＇s trichrome staining. Conclusions： Tooth germ cells still maintain the genetic signals. The solution of dermal matrix used as scaffold is favorable for further interaction and rearrangement of tooth germ cells. After implantation, the tissue-engineered tooth germ has a potential to further mature, mineralize and form the tooth with regular arranged structures.