Murphy W L, Peters M C, Kohn D H, Mooney D J
Department of Biomedical Engineering, University of Michigan, Ann Arbor 48109-2136, USA.
Biomaterials. 2000 Dec;21(24):2521-7. doi: 10.1016/s0142-9612(00)00120-4.
Strategies to engineer bone tissue have focused on either: (1) the use of scaffolds for osteogenic cell transplantation or as conductive substrates for guided bone regeneration; or (2) release of inductive bioactive factors from these scaffold materials. This study describes an approach to add an inductive component to an osteoconductive scaffold for bone tissue engineering. We report the release of bioactive vascular endothelial growth factor (VEGF) from a mineralized, porous, degradable polymer scaffold. Three dimensional, porous scaffolds of the copolymer 85 : 15 poly(lactide-co-glycolide) were fabricated by including the growth factor into a gas foaming/particulate leaching process. The scaffold was then mineralized via incubation in a simulated body fluid. Growth of a bone-like mineral film on the inner pore surfaces of the porous scaffold is confirmed by mass increase measurements and quantification of phosphate content within scaffolds. Release of 125I-labeled VEGF was tracked over a 15 day period to determine release kinetics from the mineralized scaffolds. Sustained release from the mineralized scaffolds was achieved, and growth of the mineral film had only a minor effect on the release kinetics from the scaffolds. The VEGF released from the mineralized and non-mineralized scaffolds was over 70% active for up to 12 days following mineralization treatment, and the growth of mineral had little effect on total scaffold porosity.
（1）使用支架进行成骨细胞移植，或作为引导骨再生的传导性基质；（2）从这些支架材料中释放诱导性生物活性因子。本研究描述了一种在骨组织工程的骨传导支架中添加诱导成分的方法。我们报道了生物活性血管内皮生长因子（VEGF）从一种矿化、多孔、可降解的聚合物支架中的释放情况。通过将生长因子纳入气体发泡/颗粒沥滤过程，制备了共聚物85:15聚（丙交酯-共-乙交酯）的三维多孔支架。然后将该支架在模拟体液中孵育使其矿化。通过质量增加测量和支架内磷酸盐含量的定量分析，证实了多孔支架内孔表面有类骨矿物质膜的生长。在15天的时间内追踪125I标记的VEGF的释放情况，以确定矿化支架的释放动力学。实现了从矿化支架的持续释放，并且矿物质膜的生长对支架的释放动力学仅有轻微影响。矿化和未矿化支架释放的VEGF在矿化处理后的12天内活性超过70%，并且矿物质的生长对支架的总孔隙率影响很小。
