Radder A M, Leenders H, van Blitterswijk C A
Bio Scan, Bilthoven, The Netherlands.
J Biomed Mater Res. 1996 Mar;30(3):341-51. doi: 10.1002/(SICI)1097-4636(199603)30:3<341::AID-JBM8>3.0.CO;2-Q.
A range of polyethylene oxide/polybutylene terephthalate (PEO/PBT) copolymers (70-30% PEO) was investigated for nonloadbearing bone replacement application. Porous PEO/PBT cylinders (d = 5 mm, h = 7 mm) were implanted transcortically in the diaphyseal femur of 10 goats, and the animals were sacrificed at 3, 6, 9, 12, and 26 weeks. Qualitative evaluation was performed using light and fluorescence microscopy, scanning electron microscopy, and back-scatter electron imaging with an attached X-ray microanalysis system. The percentage of bone ingrowth and the percentage of bone contact in the pore region were quantitatively assessed using undecalcified histological sections. The hydrogel properties of the PEO/PBT copolymers provided a rapid closure of the defect upon press-fit implantation, due to postoperative water uptake and subsequent swelling behavior of the materials. Bridging of the defect by bone and the occurrence of bone bonding were observed 6 weeks postoperatively for the material with the highest PEO content (70/30). For the 60/40 and 55/45 PEO/PBT proportions, union of the defect and bone bonding were observed at 9 and 12 weeks, respectively. The stiffer 40/60 and 30/70 PEO/PBT implants showed bridging of the 5-mm gap after 12 weeks, but did not reveal bone bonding up to 26 weeks. Peripheral fragmentation, mainly in the marrow cavity, was found for the 70/30 material at 12 weeks and had increased at 26 weeks. Degradation was not seen for the other materials. The histomorphometrical data confirmed the microscopical observations and demonstrated a direct relation between PEO content in the PEO/PBT co-polymers, the rate of bone ingrowth, and the amount of bone contact. Porous PEO/PBT copolymers are degradable, bone-bonding elastomeric substrates with favorable handling properties and a high percentage of bone ingrowth (69-78 at 26 weeks). It was therefore concluded that PEO/ PBT copolymers are highly promising materials for bone-replacement surgery.
研究了一系列聚环氧乙烷/聚对苯二甲酸丁二醇酯（PEO/PBT）共聚物（PEO含量为70 - 30%）在非承重骨替代应用中的性能。将多孔PEO/PBT圆柱体（直径 = 5 mm，高 = 7 mm）经皮质植入10只山羊的股骨干中，并在3、6、9、12和26周时处死动物。使用光学显微镜、荧光显微镜、扫描电子显微镜以及配备X射线微分析系统的背散射电子成像进行定性评估。使用未脱钙组织切片定量评估孔隙区域内骨长入的百分比和骨接触的百分比。PEO/PBT共聚物的水凝胶特性使得在压配合植入后由于材料术后吸水及随后的肿胀行为而迅速封闭缺损。对于PEO含量最高（70/30）的材料，术后6周观察到骨对缺损的桥接和骨结合的发生。对于60/40和55/45的PEO/PBT比例，分别在9周和12周观察到缺损的愈合和骨结合。较硬的40/60和30/70 PEO/PBT植入物在12周后显示出5 mm间隙的桥接，但直至26周都未显示骨结合。在12周时发现70/30材料存在外周碎裂，主要在骨髓腔，且在26周时有所增加。其他材料未见降解。组织形态计量学数据证实了显微镜观察结果，并表明PEO/PBT共聚物中的PEO含量、骨长入速率和骨接触量之间存在直接关系。多孔PEO/PBT共聚物是可降解的、具有骨结合能力的弹性体基质，具有良好的操作性能和较高的骨长入百分比（26周时为69 - 78）。因此得出结论，PEO/PBT共聚物是骨置换手术中非常有前景的材料。
