School of Stomatology, Lanzhou University, No.199, Donggang West Road, Lanzhou City, Gansu Province 730000, China.
Tissue Cell. 2019 Dec;61:21-29. doi: 10.1016/j.tice.2019.08.003. Epub 2019 Aug 7.
Over-dependence on existing synthetic scaffolds and insufficient vascularization limit the development of tissue engineered bone (TEB). The purpose of this study is to fabricate vascularized and scaffold-free bone tissue using cell sheet technology and to assess its feasibility to repair critical-sized calvarial defects in rats. Firstly, the pre-vascularized cell sheet was formed by seeding BMSC-derived endothelial cells (ECs) on an undifferentiated BMSCs cell sheet layer in vitro. After 3 days of co-culture, ECs migrated and rearranged to form lumens on the BMSC sheet. Secondly, osteogenic cell sheet was formed by inducing osteogenic differentiation of high density BMSCs. Then, the pre-vascularized cell sheet was stacked on BMSC-derived osteogenic cell sheet to fabricate a scaffold-free construct for bone regeneration. Finally, the scaffold-free construct with both angiogenic and osteogenic potential was implanted into critical-sized calvarial defects in adult Wistar rats. Results showed that more functional perfused blood vessels and new bone tissue formed in the pre-vascularized group than that in the controls (both empty and non-pre-vascularized cell sheet group). This study indicates a new promising strategy for bone tissue regeneration.
过度依赖现有的合成支架和血管化不足限制了组织工程骨（TEB）的发展。本研究旨在利用细胞片层技术构建血管化和无支架的骨组织，并评估其在修复大鼠临界尺寸颅骨缺损中的可行性。首先，将骨髓间充质干细胞（BMSCs）来源的内皮细胞（ECs）接种在未分化的 BMSCs 细胞片层上，在体外形成预血管化细胞片层。共培养 3 天后，ECs 迁移并重新排列在 BMSC 片层上形成管腔。其次，通过诱导高密度 BMSCs 成骨分化形成成骨细胞片层。然后，将预血管化细胞片层堆叠在 BMSC 来源的成骨细胞片层上，构建用于骨再生的无支架构建体。最后，将具有血管生成和成骨潜能的无支架构建体植入成年 Wistar 大鼠的临界尺寸颅骨缺损中。结果表明，与对照组（空的和非预血管化细胞片层组）相比，预血管化组形成了更多功能性灌注血管和新骨组织。本研究为骨组织再生提供了一种新的有前途的策略。
