Regenerative endodontic procedures (REPs) are a new option for the treatment of dental pulp or periapical diseases in permanent teeth with open apices. Histologically, the new tissues formed in the root canal after REPs are mainly cementum- or bone-like mineralised tissues, but not the real dentine-pulp complex. Therefore, how to promote dentine-pulp complex regeneration and improve the clinical effects of REPs has become a prominent research topic. Stem cells from apical papilla (SCAP) are derived from the dental papilla that can differentiate into primary odontoblasts and dental pulp cells that produce root dentine and dental pulp. Exosomes are the key regulator for the paracrine activity of stem cells and can influence the function of recipient cells. In this study, SCAP-derived exosomes (SCAP-Exo) were introduced into the root fragment containing bone marrow mesenchymal stem cells (BMMSCs) and transplanted subcutaneously into immunodeficient mice. We observed that dental pulp-like tissues were present and the newly formed dentine was deposited onto the existing dentine in the root canal. Afterwards, the effects of SCAP-Exo on the dentinogenesis of BMMSCs were elucidated in vitro. We found that the gene and protein expression of dentine sialophosphoprotein and mineralised nodule formation in BMMSCs treated with SCAP-Exo were significantly increased. In summary, SCAP-Exo were endocytosed by BMMSCs and obviously improved their specific dentinogenesis. The use of exosomes derived from dental stem cells could comprise a potential therapeutic approach for dentine-pulp complex regeneration in REPs.

中文翻译：

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根尖乳头的干细胞衍生的外泌体通过诱导特定的牙本质发生来促进牙本质-牙髓复合物的再生。

再生牙髓治疗程序（REPs）是治疗具有开放性顶点的恒牙的牙髓或根尖周疾病的新选择。组织学上，REP后在根管中形成的新组织主要是牙骨质或骨样矿化组织，而不是真正的牙髓浆复合物。因此，如何促进牙本质浆复合体的再生并改善REPs的临床效果成为一个突出的研究课题。根尖乳头（SCAP）的干细胞来自牙乳头，可以分化为原代成牙本质细胞和牙髓细胞，产生牙根和牙髓。外来体是干细胞旁分泌活性的关键调节剂，可影响受体细胞的功能。在这个研究中，将SCAP衍生的外来体（SCAP-Exo）引入含有骨髓间充质干细胞（BMMSC）的根片段中，并皮下移植到免疫缺陷小鼠中。我们观察到存在牙髓样组织，并且新形成的牙本质沉积在根管中现有的牙本质上。之后，阐明了SCAP-Exo对BMMSCs牙本质发生的影响。体外。我们发现，用SCAP-Exo处理的BMMSC中牙本质唾液磷蛋白的基因和蛋白质表达以及矿化的结节形成均显着增加。总之，SCAP-Exo被BMMSC内吞，并明显改善了它们的特异性牙本质生成。来源于牙齿干细胞的外泌体的使用可能包括REP中牙本质-牙髓复合体再生的潜在治疗方法。