Ibim S E, Uhrich K E, Attawia M, Shastri V R, El-Amin S F, Bronson R, Langer R, Laurencin C T
Department of Biology, Morris Brown College, Atlanta, Georgia 30314, USA.
J Biomed Mater Res. 1998 Winter;43(4):374-9. doi: 10.1002/(sici)1097-4636(199824)43:4<374::aid-jbm5>3.0.co;2-5.
A novel class of polymers with mechanical properties similar to cancellous bone are being investigated for their ability to be used in weight-bearing areas for orthopedic applications. The poly(anhydride-co-imide) polymers based on poly[trimellitylimidoglycine-co-1,6-bis(carboxyphenoxy)hexan e] (TMA-Gly:CPH) and poly[pyromellitylimidoalanine-co-1,6-bis(carboxyphenoxy)hexa ne] (PMA-Ala:CPH) in molar ratios of 30:70 were investigated for osteocompatibility, with effects on the healing of unicortical 3-mm defects in rat tibias examined over a 30-day period. Defects were made with surgical drill bits (3-mm diameter) and sites were filled with poly(anhydride-co-imide) matrices and compared to the control poly(lactic acid-glycolic acid) (PLAGA) (50:50), a well-characterized matrix frequently used in bone regeneration studies, and defects without polymeric implants. At predetermined time intervals (3, 6, 9, 12, 20, and 30 days), animals were sacrificed and tissue histology was examined for bone formation, polymer-tissue interaction, and local tissue response by light microscopy. The studies revealed that matrices of TMA-Gly:CPH and PMA-Ala:CPH produced responses similar to the control PLAGA with tissue compatibility characterized by a mild response involving neutrophils, macrophages, and giant cells throughout the experiment for all matrices studied. Matrices of PLAGA were nearly completely degraded by 21 days in contrast to matrices of TMA-Gly:CPH and PMA-Ala:CPH that displayed slow erosion characteristics and maintenance of shape. Defects in control rats without polymer healed by day 12, defects containing PLAGA healed after 20 days, and defects containing poly(anhydride-co-imide) matrices produced endosteal bone growth as early as day 3 and formed bridges of cortical bone around matrices by 30 days. In addition, there was marrow reconstitution at the defect site for all matrices studied along with matured bone-forming cells. This study suggests that novel poly(anhydride-co-imides) are promising polymers that may be suitable for use as implants in bone surgery, especially in weight-bearing areas.
正在研究一类新型聚合物，其机械性能与松质骨相似，探讨其在骨科应用的承重部位使用的能力。研究了基于聚[偏苯三酸亚氨基甘氨酸-co-1,6-双（羧基苯氧基）己烷]（TMA-Gly:CPH）和聚[均苯四酸亚氨基丙氨酸-co-1,6-双（羧基苯氧基）己烷]（PMA-Ala:CPH）、摩尔比为30:70的聚（酸酐-共-酰亚胺）聚合物的骨相容性，在30天的时间内观察其对大鼠胫骨单皮质3毫米缺损愈合的影响。用手术钻头（直径3毫米）制造缺损，缺损部位填充聚（酸酐-共-酰亚胺）基质，并与对照聚（乳酸-乙醇酸）（PLAGA）（50:50）进行比较，PLAGA是一种在骨再生研究中常用的、特性明确的基质，同时设置无聚合物植入物的缺损作为对照。在预定的时间间隔（3、6、9、12、20和30天），处死动物，通过光学显微镜检查组织学，观察骨形成、聚合物-组织相互作用和局部组织反应。研究表明，TMA-Gly:CPH和PMA-Ala:CPH基质产生的反应与对照PLAGA相似，在整个实验过程中，所有研究基质的组织相容性表现为涉及中性粒细胞、巨噬细胞和巨细胞的轻度反应。与TMA-Gly:CPH和PMA-Ala:CPH基质显示出缓慢侵蚀特性并保持形状不同，PLAGA基质在21天时几乎完全降解。无聚合物的对照大鼠的缺损在第12天愈合，含PLAGA的缺损在20天后愈合，含聚（酸酐-共-酰亚胺）基质的缺损早在第3天就产生了骨内膜骨生长，并在30天时在基质周围形成皮质骨桥。此外，所有研究基质的缺损部位都有骨髓重建，同时伴有成熟的成骨细胞。这项研究表明，新型聚（酸酐-共-酰亚胺）是有前景的聚合物，可能适合用作骨外科手术中的植入物，尤其是在承重部位。
