Department of Implantology, Stomatology Hospital, School of Medicine, ‡Department of Oral and Maxillofacial Surgery, Stomatology Hospital, School of Medicine, and §Department of Oral Medicine, Stomatology Hospital, School of Medicine, Zhejiang University , Yan'an Road, Hangzhou 310058, P. R. China.
ACS Appl Mater Interfaces. 2017 Oct 11;9(40):34674-34686. doi: 10.1021/acsami.7b10184. Epub 2017 Sep 26.
The combination of bone marrow mesenchymal stem cell (BMSC) sheets and titanium implants (BMSC sheet-implant complexes) can accelerate osseointegration. However, methods of fabricating BMSC sheet-implant complexes are quite limited, and the survival of BMSC sheet-implant complexes is one of the key barriers. Here, we show that a light-controlled fabricating system can generate less injured BMSC sheet-implant complexes with improved viability and osteogenesis and that noninvasive monitoring of the viability of BMSC sheet-implant complexes using a lentiviral delivery system is feasible. Enhanced green fluorescent protein- and luciferase-expressing BMSC sheets were used to track the viability of BMSC sheet-implant complexes in vivo. The experiments of micro-computed tomography analysis and hard tissue slices were performed to evaluate the osteogenic ability of BMSC sheet-implant complexes in vivo. The results showed that BMSC sheet-implant complexes survived for almost 1 month after implantation. Notably, BMSC sheet-implant complexes fabricated by the light-controlled fabricating system had upregulating expression levels of low-density lipoprotein-receptor-related protein 5 (LRP5), β-catenin, and runt-related transcription factor 2 (Runx2) compared to the complexes fabricated by mechanical scraping. Furthermore, we found that Runx2 directly bound to the rat LRP5 promoter and the LRP5/β-catenin/Runx2 regulatory loop contributed to the enhancement of the osseointegrating potentials. In this study, we successfully fabricated BMSC sheet-implant complexes with improved viability and osteogenesis and established a feasible, noninvasive, and continuous method for tracking BMSC sheet-implant complexes in vivo. Our findings lay the foundation for the application of BMSC sheet-implant complexes in vivo and open new avenues for engineered BMSC sheet-implant complexes.
骨髓间充质干细胞（BMSC）片与钛植入物（BMSC 片-植入物复合物）的结合可以加速骨整合。然而，制造 BMSC 片-植入物复合物的方法相当有限，BMSC 片-植入物复合物的存活率是关键障碍之一。在这里，我们展示了一种光控制造系统可以产生更少损伤的 BMSC 片-植入物复合物，提高其活力和成骨能力，并且使用慢病毒传递系统对 BMSC 片-植入物复合物的活力进行非侵入性监测是可行的。表达增强型绿色荧光蛋白和荧光素酶的 BMSC 片用于体内跟踪 BMSC 片-植入物复合物的活力。进行了微计算机断层扫描分析和硬组织切片实验，以评估 BMSC 片-植入物复合物在体内的成骨能力。结果表明，BMSC 片-植入物复合物在植入后几乎存活了 1 个月。值得注意的是，与机械刮削制造的复合物相比，光控制造系统制造的 BMSC 片-植入物复合物的低密度脂蛋白受体相关蛋白 5（LRP5）、β-连环蛋白和 runt 相关转录因子 2（Runx2）的表达水平上调。此外，我们发现 Runx2 直接与大鼠 LRP5 启动子结合，LRP5/β-连环蛋白/Runx2 调节环有助于增强整合潜力。在这项研究中，我们成功制造了具有更高活力和成骨能力的 BMSC 片-植入物复合物，并建立了一种可行、非侵入性和连续的方法来跟踪体内的 BMSC 片-植入物复合物。我们的发现为 BMSC 片-植入物复合物在体内的应用奠定了基础，并为工程化 BMSC 片-植入物复合物开辟了新途径。
