The State Key Laboratory of Bioreactor Engineering, Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People's Republic of China.
Biomed Mater. 2012 Jun;7(3):035002. doi: 10.1088/1748-6041/7/3/035002. Epub 2012 Feb 23.
The reconstruction of segmental bone defects remains an urgent problem in the orthopaedic field, and bone morphogenetic protein-2 (BMP-2) is known for its potent osteoinductive properties in bone regeneration. In this study, chitosan microspheres (CMs) were prepared and combined with absorbable collagen sponge to maintain controlled-release recombinant human bone morphogenetic protein-2 (rhBMP-2). The rhBMP-2-loaded composite scaffolds were implanted into 15 mm radius defects of rabbits and the bone-repair ability was evaluated systematically. CMs were spherical in shape and had a polyporous surface, according to SEM images. The complex scaffold exhibited an ideal releasing profile in vitro. The micro-computed tomographic analysis revealed that the rhBMP-2-loaded composite scaffold not only bridged the defects as early as 4 weeks, but also healed the defects and presented recanalization of the bone-marrow cavity at 12 weeks. These results were confirmed by x-ray. When compared with other control groups, the composite scaffold group remarkably enhanced new bone formation and mechanical properties, as evidenced by bone mineral content evaluation, histological observations and biomechanical testing. Moreover, the biocompatibility and appropriate degradation of the composite scaffold could be obtained. All of these results clearly demonstrated that the composite scaffold is a promising carrier of BMP-2 for the treatment of segmental bone defects.
骨段缺损的重建仍然是骨科领域的一个迫切问题，骨形态发生蛋白-2（BMP-2）在骨再生中具有很强的成骨诱导特性。在这项研究中，制备了壳聚糖微球（CMs）并将其与可吸收胶原海绵结合，以维持控释重组人骨形态发生蛋白-2（rhBMP-2）。将负载 rhBMP-2 的复合支架植入兔 15mm 半径缺损处，系统评估其骨修复能力。根据 SEM 图像，CMs 呈球形，具有多孔表面。体外复合支架表现出理想的释放曲线。微 CT 分析显示，负载 rhBMP-2 的复合支架不仅在 4 周时早期桥接缺损，而且在 12 周时愈合缺损并呈现骨髓腔再通。X 射线证实了这一点。与其他对照组相比，复合支架组明显促进了新骨形成和机械性能，这可以通过骨矿物质含量评估、组织学观察和生物力学测试来证明。此外，还可以获得复合支架的生物相容性和适当的降解。所有这些结果都清楚地表明，该复合支架是治疗骨段缺损的 BMP-2 的一种有前途的载体。
