Niemelä T, Niiranen H, Kellomäki M, Törmälä P
Institute of Biomaterials, Tampere University of Technology, P.O. Box 589, FIN-33101 Tampere, Finland.
Acta Biomater. 2005 Mar;1(2):235-42. doi: 10.1016/j.actbio.2004.11.002. Epub 2004 Dec 25.
Spherical bioactive glass 13-93 particles, with a particle size distribution of 50-125 microm, were combined with bioabsorbable poly-L,DL-lactide 70/30 using twin-screw extrusion. The composite rods containing 0, 20, 30, 40 and 50 wt% of bioactive glass were further self-reinforced by drawing to a diameter of approximately 3 mm. The bioactive glass spheres were well dispersed and the open pores were formed on the composite surface during drawing. The initial mechanical properties were studied. The addition of bioactive glass reduced the bending strength, bending modulus, shear strength, compression strength and torsion strength of poly-L,DL-lactide. However, the strain at maximum bending load increased in self-reinforced composites. Initially brittle composites became ductile in self-reinforcing. The bioactivity was studied in phosphate buffered saline for up to 12 days. The formation of calcium phosphate precipitation was followed using scanning electron microscopy and energy dispersive X-ray analysis. Results showed that the bioactive glass addition affected the initial mechanical properties and bioactivity of the composites. It was concluded that the optimal bioactive glass content depends on the applications of the composites.
粒径分布为50 - 125微米的球形生物活性玻璃13 - 93颗粒，通过双螺杆挤出与生物可吸收的聚-L，DL-丙交酯70/30相结合。含有0、20、30、40和50 wt%生物活性玻璃的复合棒材通过拉伸至直径约3毫米进一步实现自增强。生物活性玻璃球体分散良好，在拉伸过程中复合表面形成了开孔。研究了其初始力学性能。生物活性玻璃的添加降低了聚-L，DL-丙交酯的弯曲强度、弯曲模量、剪切强度、压缩强度和扭转强度。然而，在自增强复合材料中，最大弯曲载荷下的应变增加。最初脆性的复合材料在自增强过程中变得具有韧性。在磷酸盐缓冲盐水中对生物活性进行了长达12天的研究。使用扫描电子显微镜和能量色散X射线分析跟踪磷酸钙沉淀的形成。结果表明，生物活性玻璃的添加影响了复合材料的初始力学性能和生物活性。得出的结论是，最佳生物活性玻璃含量取决于复合材料的应用。
