Department of Biomaterials, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Acta Biomater. 2011 Apr;7(4):1752-9. doi: 10.1016/j.actbio.2010.12.020. Epub 2010 Dec 24.
In this study, we investigated the in vivo degradation properties and tissue response towards injectable calcium phosphate cement (CPC) with no further addition, or calcium phosphate composite cement containing approximately 50 vol.% of microspheres. Three types of spheres were assessed, i.e. poly(lactic-co-glycolic acid) (PLGA), gelatin (GEL) and poly(trimethylene carbonate) (PTMC). The cements were injected into 4.6 mm diameter and 6mm deep cylindrical defects in the femoral condyle of New Zealand white rabbits, hardened in situ and, after wound closure, left to heal for 4, 8 and 12 weeks (n=6 for each composition and time period). After retrieval, specimens were analyzed using histological and histomorphometrical methods. Results showed that non-modified CPCs showed excellent bone contact but only very limited erosion at the surface. The CPC/PLGA implant degraded almost completely, while tissue response significantly improved at each time period. CPC/PTMC showed slower degradation characteristics compared to CPC/PLGA. Finally, at all time periods, there was an evident inflammatory response to the CPC/GEL composite cement. In conclusion, the degradation properties of the CPC/PLGA microspheres composite and its bone response when implanted into the femoral condyles of rabbits were significantly better than those of CPC/gelatin and CPC/PTMC microspheres composites.
在这项研究中，我们研究了可注射磷酸钙水泥（CPC）的体内降解特性和组织反应，这些水泥没有进一步添加成分，或者含有大约 50%体积分数的微球的磷酸钙复合水泥。我们评估了三种类型的微球，即聚（乳酸-共-乙醇酸）（PLGA）、明胶（GEL）和聚（三亚甲基碳酸酯）（PTMC）。将水泥注入新西兰白兔股骨髁的直径为 4.6 毫米、深度为 6 毫米的圆柱形缺陷中，就地硬化，然后在伤口闭合后，让其愈合 4、8 和 12 周（每种成分和时间段各 6 只）。取出后，使用组织学和组织形态计量学方法对标本进行分析。结果表明，未改性的 CPC 表现出优异的骨接触，但表面仅发生非常有限的侵蚀。CPC/PLGA 植入物几乎完全降解，而组织反应在每个时间段都显著改善。CPC/PTMC 与 CPC/PLGA 相比，降解特性较慢。最后，在所有时间段，CPC/GEL 复合材料的炎症反应明显。总之，当植入兔股骨髁时，CPC/PLGA 微球复合材料的降解特性及其骨反应明显优于 CPC/明胶和 CPC/PTMC 微球复合材料。
