Verheyen C C, de Wijn J R, van Blitterswijk C A, de Groot K, Rozing P M
Department of Biomaterials, School of Medicine, University of Leiden, The Netherlands.
J Biomed Mater Res. 1993 Apr;27(4):433-44. doi: 10.1002/jbm.820270404.
In the development of new materials for resorbable systems for bone fixation and replacement, composites of hydroxylapatite and poly (L-lactide) (HA/PLLA) were tested. In a transcortical implantation model in goats the interactions at the bone-implant interface were studied with post-operative intervals up to 1 year. Push-out testing of the implants indicated that PLLA reinforced with 50 wt% hydroxylapatite or PLLA plasma-sprayed with a hydroxylapatite coating of 50 microns thickness increases interfacial shear strength at 3 months of implantation when compared to unfilled poly(L-lactide) (P < .01). Scanning electron microscopy showed that the failure mode was predominantly at the coating-implant interface. Implantation periods longer than 3 months did not result in a significant increase in push-out strength because of the resorbing PLLA matrix. In support of the above findings there was histological evidence, on a light microscopical level, of increased bone contact at the interface for the composites, HA incorporated in or coated on PLLA, compared to unfilled poly(L-lactide).
在用于骨固定和替代的可吸收系统新材料的研发过程中，对羟基磷灰石与聚（L-丙交酯）（HA/PLLA）复合材料进行了测试。在山羊的经皮质植入模型中，研究了长达1年术后间隔时间内骨-植入物界面的相互作用。植入物的推出试验表明，与未填充的聚（L-丙交酯）相比，用50 wt%羟基磷灰石增强的PLLA或喷涂有50微米厚羟基磷灰石涂层的PLLA在植入3个月时可提高界面剪切强度（P <.01）。扫描电子显微镜显示，失效模式主要发生在涂层-植入物界面。由于PLLA基体的吸收，植入时间超过3个月并未导致推出强度显著增加。与未填充的聚（L-丙交酯）相比，在光学显微镜水平上有组织学证据支持上述发现，即对于PLLA中掺入或涂覆HA的复合材料，界面处的骨接触增加。
