人乳牙牙髓干细胞膜片在组织工程牙髓再生中的实验研究

Experimental Research on Regeneration of Dental Pulp with Stem Cells Derived from Exfoliated Deciduous Teeth

目的:选用人乳牙牙髓干细胞(Stem cells derived from exfoliated deciduous teeth,SHED)作为种子细胞构建细胞膜片,探索适宜SHED进行牙髓再生所需的微环境,并且比较人乳牙牙髓干细胞膜片和细胞-聚乙丙交酯(PLGA)复合物(SHED-PLGA)两种不同的构建方法在组织工程牙髓再生中的效果。方法:采用酶解组织块法培养SHED,有限稀释法进行纯化,条件诱导液诱导SHED细胞膜片,并将其置于处理过的牙本质基质片段的根管内,在裸鼠体内异位构建年轻恒牙牙髓再生的实验模型。结果:制备的牙本质基质片段分别负载SHED-PLGA复合物和SHED细胞膜片后在裸鼠体内异位移植3个月,经免疫组化染色后可观察到牙本质基质片段的根管内壁有一层新形成的牙本质样基质和单层不连续排列的成牙本质细胞样细胞,通过灰度扫描分析可知:SHED细胞膜片组的组织生成量明显高于SHED-PLGA组。结论:利用条件诱导液可以形成SHED细胞膜片,SHED细胞膜片和SHED-PLGA均可在体内形成牙髓-牙本质复合体样结构,SHED细胞膜片组的组织生成量明显高于SHEDPLGA组,细胞膜片可以为牙髓再生提供新的实验方法。

Objective SHED were used as seed cells to construct cell membrane,and the microenvironment for pulp regeneration was explored.The eff ects of two diff erent construction methods,cell membrane and cell scaff old composite,on pulp regeneration of tissue engineering were compared.Methods SHED were cultured by enzymolysis and purifi ed by limited dilution method.The membrane of SHED cells was induced by conditioned medium and placed in the root canal of the treated dentin matrix fragment.The experimental model of pulp regeneration of young permanent teeth was established in nude mice.Results After loading SHED-PLGA complex and SHED cell membrane into nude mice for 3 months.Immunohistochemical staining showed that there was a new layer of dentin-like matrix and a single layer of non continuous odontoblast-like cells on the inner wall of the root canal of the dentin matrix fragment.The amount of tissue formation in SHED membrane group was signifi cantly higher than that in SHED-PLGA group.Conclusion SHED membrane and SHED-PLGA can form pulp dentin complex structure in vivo,and the tissue production of SHED membrane group is signifi cantly higher than that of SHED-PLGA group,which can provide a new experimental method for pulp regeneration.