Department of Biomaterials, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Acta Biomater. 2012 Jan;8(1):404-14. doi: 10.1016/j.actbio.2011.08.010. Epub 2011 Aug 18.
Porosity and interconnectivity are important properties of calcium phosphate cements (CPCs) and bone-replacement materials. Porosity of CPCs can be achieved by adding polymeric biodegradable pore-generating particles (porogens), which can add porosity to the CPC and can also be used as a drug-delivery system. Porosity affects the mechanical properties of CPCs, and hence is of relevance for clinical application of these cements. The current study focused on the effect of combinations of polymeric mesoporous porogens on the properties of a CPC, such as specific surface area, porosity and interconnectivity and the development of mechanical properties. CPC powder was mixed with different amounts of PLGA porogens of various molecular weights and porogen sizes. The major factors affecting the properties of the CPC were related to the amount of porogen loaded and the porogen size; the molecular weight did not show a significant effect per se. A minimal porogen size of 40 μm in 30 wt.% seems to produce a CPC with mechanical properties, porosity and interconnectivity suitable for clinical applications. The properties studied here, and induced by the porogen and CPC, can be used as a guide to evoke a specific host-response to maintain CPC integrity and to generate an explicit bone ingrowth.
多孔性和连通性是磷酸钙骨水泥（CPC）和骨替代材料的重要特性。通过添加可生物降解的聚合物多孔生成粒子（成孔剂）可以实现 CPC 的多孔性，这些成孔剂可以为 CPC 添加多孔性，也可以用作药物输送系统。多孔性会影响 CPC 的机械性能，因此与这些水泥的临床应用密切相关。本研究主要关注聚合物介孔成孔剂的组合对 CPC 的特性（如比表面积、孔隙率和连通性以及机械性能的发展）的影响。将 CPC 粉末与不同分子量和粒径的不同用量的 PLGA 成孔剂混合。影响 CPC 性能的主要因素与加载的成孔剂数量和成孔剂粒径有关；分子量本身并没有显著影响。在 30wt.%的情况下，最小的成孔剂粒径为 40μm，似乎可以产生具有适合临床应用的机械性能、孔隙率和连通性的 CPC。此处研究的特性以及成孔剂和 CPC 诱导的特性可作为指导，引发特定的宿主反应，以维持 CPC 的完整性并产生明确的骨内生长。
