Department of Periodontology, School of Stomatology, Tongji University, Shanghai, China.
J Periodontol. 2012 Jun;83(6):805-15. doi: 10.1902/jop.2011.110267. Epub 2011 Oct 20.
Functional tissue regeneration underscores the construction of favorable extracellular matrix environment and neovascularization. In this study, we propose a mixed-type stem cell-pellet cultivation system for human periodontal ligament stem cells (hPDLSCs) to recreate a favorable regeneration microenvironment.
The hPDLSCs were cocultured with human bone marrow mesenchymal stem cells (hBMMSCs) and mixed by osteoinduced ceramic bovine bone (CBB) powder as a mixed-type stem cell sheet. The influence of osteoinduced CBB on hPDLSCs was analyzed by alkaline phosphatase (ALP) and osteogenic differentiation assays. The effects of hBMMSCs on hPDLSCs were estimated by proliferating cell nuclear antigen, ALP, real-time reverse transcription polymerase chain reaction, and Western blot assays. The mixed-cell sheet was the preliminary observations in vitro that laid the foundation for additional implantation. After the cells were detached, the mixed-type sheet spontaneously contracted to produce a mixed-type stem cell pellet, which was transplanted into immunocompromised mice.
In vitro, the results showed that osteoinduced CBB could upregulate ALP activity and accelerate mineralization of hPDLSCs. When the hPDLSCs were cocultured with hBMMSCs, the ALP activity and proliferation kinetics were upregulated and also indicated in the expression of collagen I, osteocalcin, and vascular endothelial growth factor. It was found that, in vivo, the mixed-type hPDLSC pellets support cementum/periodontal ligament (PDL)-like tissue regeneration with neovascularization.
These results suggest that the mixed-type hPDLSC pellet could mimic the microenvironment of PDL and enhance the reconstruction of physiologic architecture of a dental cementum/PDL-like complex. This tissue mimicking may also be a promising alternative to promote periodontal defect repair for additional clinical applications.
功能性组织再生强调构建有利的细胞外基质环境和新血管生成。在本研究中，我们提出了一种混合型干细胞-微球培养系统，用于培养人牙周膜干细胞（hPDLSCs），以重建有利的再生微环境。
将 hPDLSCs 与骨髓间充质干细胞（hBMMSCs）共培养，并与诱导成骨的陶瓷牛骨（CBB）粉末混合形成混合型干细胞片。通过碱性磷酸酶（ALP）和成骨分化试验分析诱导成骨的 CBB 对 hPDLSCs 的影响。通过增殖细胞核抗原、ALP、实时逆转录聚合酶链反应和 Western blot 试验评估 hBMMSCs 对 hPDLSCs 的影响。混合细胞片在体外的初步观察为进一步植入奠定了基础。细胞脱离后，混合型片会自动收缩形成混合型干细胞微球，并移植到免疫缺陷小鼠体内。
体外结果表明，诱导成骨的 CBB 可以上调 hPDLSCs 的 ALP 活性并加速其矿化。当 hPDLSCs 与 hBMMSCs 共培养时，ALP 活性和增殖动力学得到上调，同时胶原 I、骨钙素和血管内皮生长因子的表达也得到上调。体内研究发现，混合型 hPDLSC 微球可支持牙骨质/牙周膜（PDL）样组织再生和新血管生成。
这些结果表明，混合型 hPDLSC 微球可以模拟 PDL 的微环境，增强生理性牙骨质/PDL 样复合体的结构重建。这种组织模拟可能也是促进牙周缺损修复的有前途的替代方法，具有广阔的临床应用前景。
