Bakker D, van Blitterswijk C A, Hesseling S C, Koerten H K, Kuijpers W, Grote J J
Ear, Nose & Throat Dept., University Hospital, Leiden, The Netherlands.
J Biomed Mater Res. 1990 Apr;24(4):489-515. doi: 10.1002/jbm.820240407.
The biocompatibility of porous implants made of Estane 5714 F1 polyether urethane, polypropylene oxide, and a poly(ethylene oxide hydantoin) and poly(tetramethylene terephthalate) segmented polyether polyester copolymer (HPOE/PBT copolymer), which were selected as candidates for an alloplastic tympanic membrane, was assessed after implantation in rat middle ears for periods of up to 1 year. Implantation of the materials led to tissue reactions initially associated with the wound-healing process, whereas after 1 month not only the presence of macrophages and foreign-body giant cells surrounding the implant materials but also implant degradation were characteristic for a foreign-body reaction. Macrophages and foreign-body giant cells dominated the picture of the tissue surrounding polypropylene oxide. The altered morphology of these cells, the persistent infiltration of the implantation sites by exudate cells, and the premature death of five rats in the 1-year group suggest that polypropylene oxide degradation was accompanied by the release of toxic substances. Estane and copolymer degradation did not induce tissue responses reflecting implant toxicity, and tympanic membranes given these alloplasts showed a normal healing pattern. Inclusions in the cytoplasm of macrophages associated with degradation and phagocytosis of all of the polymers under study were found to contain iron, silicon, titanium, and aluminum. Growth of fibrous tissue and bone, the latter into Estane and HPOE/PBT copolymer implants, indicated appropriate implant fixation by tissue, although macrophages and foreign-body giant cells were present as well. Especially the fixation of copolymer by ingrowth of bone seems promising in terms of the amount of bone in the pores and the electron-dense bone/copolymer interface. The latter is indicative for bonding osteogenesis. The HPOE/PBT copolymer is a better candidate for alloplastic tympanic membrane than Estane, and the use of polypropylene oxide cannot be recommended.
将由Estane 5714 F1聚醚聚氨酯、聚环氧丙烷以及聚（乙内酰脲环氧乙烷）与聚（对苯二甲酸丁二醇酯）嵌段聚醚聚酯共聚物（HPOE/PBT共聚物）制成的多孔植入物作为人工鼓膜的候选材料，在大鼠中耳植入长达1年的时间后，对其生物相容性进行了评估。材料植入后引发了最初与伤口愈合过程相关的组织反应，而1个月后，不仅植入材料周围出现巨噬细胞和异物巨细胞，而且植入物降解成为异物反应的特征。巨噬细胞和异物巨细胞在聚环氧丙烷周围的组织图像中占主导。这些细胞形态的改变、渗出细胞对植入部位的持续浸润以及1年组中5只大鼠的过早死亡表明，聚环氧丙烷降解伴随着有毒物质的释放。Estane和共聚物降解未引发反映植入物毒性的组织反应，给予这些同种异体材料的鼓膜显示出正常的愈合模式。在与所研究的所有聚合物的降解和吞噬作用相关的巨噬细胞胞质内发现的内含物含有铁、硅、钛和铝。纤维组织和骨的生长，后者长入Estane和HPOE/PBT共聚物植入物中，表明组织对植入物的固定适当，尽管也存在巨噬细胞和异物巨细胞。特别是从孔隙中的骨量和电子致密的骨/共聚物界面来看，骨向内生长对共聚物的固定似乎很有前景。后者表明有骨结合形成。HPOE/PBT共聚物作为人工鼓膜的候选材料比Estane更好，不建议使用聚环氧丙烷。
