Am J Orthod Dentofacial Orthop. 2010 Feb;137(2):162.e1-9; discussion 162-3. doi: 10.1016/j.ajodo.2009.06.018.
The purposes of this study were to differentiate embryonic limb bud cells into cartilage, characterize the nodules produced, and determine their ability to heal a mouse skull defect.
Aggregated mouse limb bud cells (E12-E12.5), cultured in a bioreactor for 3 weeks, were analyzed by histology or implanted in 6 skull defects. Six controls had no implants. The mice were scanned with microcomputed tomography weekly. At 2 and 4 weeks, a mouse from each group was killed, and the defect region was prepared for histology.
Chondrocytes in nodules were mainly hypertrophic. About 90% of the nodules mineralized. BrdU staining showed dividing cells in the perichondrium. Microcomputed tomography scans showed increasing minerals in implanted nodules that completely filled the defect by 6 weeks; defects in the control mice were not healed by then. At 2 and 4 weeks, the control skull sections showed only a thin bony layer over the defect. At 2 weeks, bone and cartilage filled the defects with implants, and the implants were well integrated with the adjacent cortical bone. At 4 weeks, the implant had turned almost entirely into bone.
Cartilage differentiated in the bioreactor and facilitated healing when implanted into a defect. Engineering cartilage to replace bone is an alternative to current methods of bone grafting.
本研究的目的是将胚胎肢芽细胞分化为软骨，对生成的结节进行特征分析，并确定其修复小鼠颅骨缺损的能力。
在生物反应器中培养 3 周的聚集的小鼠肢芽细胞（E12-E12.5），通过组织学分析或植入 6 个颅骨缺损中进行分析。另外 6 个对照组没有植入物。每周用微计算机断层扫描对小鼠进行扫描。在第 2 周和第 4 周，每组杀死一只小鼠，将缺损区域制备用于组织学分析。
结节中的软骨细胞主要呈肥大状态。大约 90%的结节矿化。BrdU 染色显示软骨膜中有分裂细胞。微计算机断层扫描显示植入结节中的矿物质不断增加，6 周时完全填满了缺损；而对照组的缺损到那时还没有愈合。在第 2 周和第 4 周，对照组的颅骨切片仅显示缺损处有一层薄薄的骨层。第 2 周时，骨和软骨填满了植入物的缺损，植入物与相邻的皮质骨很好地整合在一起。第 4 周时，植入物几乎完全变成了骨。
软骨在生物反应器中分化，并在植入缺损时促进愈合。工程软骨替代骨是目前骨移植方法的一种替代方法。
