Department of Oral and Maxillofacial Surgery, Christian-Albrechts-University Kiel, Germany.
Oral Oncol. 2009 Nov;45(11):e181-8. doi: 10.1016/j.oraloncology.2009.07.004. Epub 2009 Aug 31.
The aim of this study was to evaluate the ability of computer assisted designed (CAD) synthetic hydroxyapatite and tricalciumphosphate blocks to serve as precise scaffolds for intramuscular bone induction in a rat model. A central channel to allow for vessel pedicle or nerve integration was added. Natural bovine hydroxyapatite blocks served as controls to evaluate and compare biocompatibility of the new matrices. Individually designed 3D-printed rounded and porous hydroxyapatite (HA) and tricalcium phosphate (TCP) blocks were placed in pouches in the Musculus latissimus dorsi in 12 Lewis rats bilaterally. Bovine hydroxyapatite blocks with and without a central channel served as controls. Simultaneously, 200 microg rhBMP-2 in 1 ml sodium chloride was injected on both sides. For 8 weeks, bone generation was monitored by computer tomography and fluorescence labeling. The increase rates of bone density in CT examinations were higher in the HA groups (184-220 HU 8 weeks after implantation) compared to the TCP group (18 HU; p<0.0001). Microradiography and fluorescence microscopy 8 weeks after implantation showed new bone formation for all materials tested. For all scaffolds, toluidine staining revealed vital bone directly on the scaffold materials but also in the gaps between. It can be concluded from our data that the specially shaped hydroxyapatite and tricalcium phosphate blocks tested against the bovine hydroxyapatite blocks showed good biocompatibility and osteoinductivity in vivo. Further studies should explore if the stability of the individually designed blocks is sufficient to cultivate larger replacements without an external matrix for support.
本研究旨在评估计算机辅助设计（CAD）合成羟基磷灰石和磷酸三钙块作为精确支架，用于在大鼠模型中诱导肌肉内骨的能力。添加了一个中央通道，以允许血管蒂或神经整合。天然牛羟基磷灰石块作为对照，以评估和比较新基质的生物相容性。分别设计的 3D 打印圆形多孔羟基磷灰石（HA）和磷酸三钙（TCP）块放置在 12 只 Lewis 大鼠双侧背阔肌的小袋中。带有和不带有中央通道的牛羟基磷灰石块作为对照。同时，在两侧注射 1ml 氯化钠中的 200μg rhBMP-2。8 周时，通过计算机断层扫描和荧光标记监测骨生成。CT 检查中骨密度的增加率在 HA 组（植入后 8 周时为 184-220HU）高于 TCP 组（18HU；p<0.0001）。植入后 8 周的微射线照相和荧光显微镜显示所有测试材料均有新骨形成。对于所有支架，甲苯胺蓝染色显示支架材料上直接有活性骨，支架材料之间也有骨。从我们的数据可以得出结论，与牛羟基磷灰石块相比，经过特殊设计的羟基磷灰石和磷酸三钙块具有良好的生物相容性和体内成骨诱导性。进一步的研究应该探索这些单独设计的支架的稳定性是否足以在没有外部基质支持的情况下培养更大的替代品。
