Devin J E, Attawia M A, Laurencin C T
Helen I. Moorehead-Laurencin Biomaterials Research Laboratory, Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, USA.
J Biomater Sci Polym Ed. 1996;7(8):661-9. doi: 10.1163/156856296x00435.
A degradable polymer-ceramic matrix for use as a bone graft material is described. The fabrication method used produces 3-dimensional macroporous matrices which are structurally similar to cancellous bone in their porosity, mechanically similar to cancellous bone in compressive elastic modulus and chemically comparable to the mineral matrix of bone in that they contain hydroxyapatite (HA). A 50:50 copolymer of poly(lactide/glycolide) (PLAGA) reinforced by a particulate calcium phosphate ceramic, HA, was used to create a matrix composed of polymeric microspheres. The channels between these spheres were pores approximately 100 microns in diameter. Four polymer/ceramic ratios were used in matrix fabrication: 1:0, 1:1, 2.5:1, and 5:1. The mechanical behavior of the material was found to vary with ceramic content. Increased levels of HA resulted in increased compressive elastic moduli. Prior to polymer degradation, moduli ranged from a high of 1459 MPa (50% HA) to a low of 293 MPa (0% HA). Degradation studies over a 6-week period showed that 0 and 16.7% HA-containing matrices lost up to 50% of their original weight, while the 28.6 and 50% IIA-containing matrices lost up to 20% of their original weight. Increased HA matrix content translated into decreased rates of matrix degradation. Environmental scanning electron microscopy (ESEM) confirmed that the polymer matrix contained pores that were interconnected during degradation. Viewed via ESEM, 10% HA containing matrices completely degraded by 6 weeks, while 50% HA matrices remained relatively stable. These studies indicate that the porous 3-dimensional polymer/ceramic matrix may potentially be useful as a synthetic material for bone repair.
描述了一种用作骨移植材料的可降解聚合物 - 陶瓷基质。所采用的制造方法可生产出三维大孔基质，其孔隙率在结构上与松质骨相似，压缩弹性模量在力学性能上与松质骨相似，并且在化学组成上与骨的矿物质基质相当，因为它们含有羟基磷灰石（HA）。由颗粒状磷酸钙陶瓷HA增强的聚（丙交酯/乙交酯）（PLAGA）50:50共聚物被用于制造由聚合物微球组成的基质。这些球体之间的通道是直径约100微米的孔隙。在基质制造中使用了四种聚合物/陶瓷比例：1:0、1:1、2.5:1和5:1。发现该材料的力学行为随陶瓷含量而变化。HA含量的增加导致压缩弹性模量增加。在聚合物降解之前，模量范围从1459兆帕（50% HA）的高位到293兆帕（0% HA）的低位。为期6周的降解研究表明，含0%和16.7% HA的基质损失了高达其原始重量的50%，而含28.6%和50% HA的基质损失了高达其原始重量的20%。HA基质含量的增加转化为基质降解速率的降低。环境扫描电子显微镜（ESEM）证实，聚合物基质在降解过程中含有相互连接的孔隙。通过ESEM观察，含10% HA的基质在6周时完全降解，而含50% HA的基质保持相对稳定。这些研究表明，多孔三维聚合物/陶瓷基质可能有潜力用作骨修复的合成材料。
