Department of Biomaterials, Dental Institute, King's College London, London, UK.
J Periodontol. 2014 Feb;85(2):298-307. doi: 10.1902/jop.2013.130159. Epub 2013 Jun 20.
Calcium phosphate-based materials have been widely used as bone substitutes and more recently are being exploited together with growth factors as bone tissue engineering scaffolds regulating cell behavior. The aim of this study is to evaluate the in vitro and in vivo response to a newly developed calcium metaphosphate (CMP) bone graft, with and without bone-stimulating growth factor.
Porous scaffolds of CMP were developed and extensively tested in vitro. Subsequently, CMP grafts with osteogenic protein-1 (OP-1) (test) and without OP-1 (control) were implanted into experimental rabbit maxillary bone defects. Animals were sacrificed at 2, 4, and 8 weeks, and samples were examined with microcomputed tomography (micro-CT) and processed for histomorphometric analysis.
At 8 weeks, the scaffolds containing OP-1 induced greater bone formation (P = 0.018) than CMP alone, based on histomorphometric evaluation (percentage bone area: test: 57.1 ± 5.6; control: 49.4 ± 7.7) and micro-CT analysis (percentage bone volume density: test: 63.46 ± 5.61; control: 51.20 ± 6.71). Thus, these data indicated that both test and control CMP grafts showed a good degree of bone formation. Furthermore, the CMP materials showed signs of resorption from 4 weeks, and no graft materials were observed at 8 weeks.
In vitro, the OP-1 loaded graft demonstrated a release profile and bioactivity over a 28-day period. In vivo testing confirmed enhanced bone formation of the OP-1 loaded graft after 8 weeks of healing.
磷酸钙基材料已被广泛用作骨替代物，最近还与生长因子一起被开发为骨组织工程支架，以调节细胞行为。本研究旨在评估一种新开发的磷酸钙镁（CMP）骨移植物的体外和体内反应，有无骨刺激生长因子。
开发了多孔 CMP 支架，并进行了广泛的体外测试。随后，将含有成骨蛋白-1（OP-1）的 CMP 移植物（试验）和不含 OP-1 的 CMP 移植物（对照）植入实验性兔上颌骨缺损。动物在 2、4 和 8 周时被处死，用微计算机断层扫描（micro-CT）检查样本，并进行组织形态计量学分析。
在 8 周时，基于组织形态计量学评价（骨面积百分比：试验：57.1 ± 5.6；对照：49.4 ± 7.7）和 micro-CT 分析（骨体积密度百分比：试验：63.46 ± 5.61；对照：51.20 ± 6.71），含 OP-1 的支架诱导的骨形成大于单独的 CMP（P = 0.018）。因此，这些数据表明，试验和对照 CMP 移植物均表现出良好的骨形成程度。此外，CMP 材料从 4 周开始出现吸收迹象，8 周时未观察到移植物材料。
在体外，负载 OP-1 的移植物在 28 天内表现出释放曲线和生物活性。体内试验证实，在 8 周的愈合后，负载 OP-1 的移植物增强了骨形成。
