明胶微球/rhBMP-2/CPC的制备及其异位成骨效应研究

目的：制备多孔复合材料明胶微球／rhBMp-2／CPC并研究其异位成骨效应。方法：双相乳化冷凝聚合法制备明胶微球，京尼平进行交联，喷金后电镜观察。交联微球携载rhBMP-2，以2．5％的比例掺入磷酸钙骨水泥（calcium phosphate cements，CPC）固化，制成实验用多孔明胶微球／rhBMP-2／CPC，rhBMP-2／CPC作为对照组．两组材料固化后分别浸入生理盐水，1、3周后进行生物力学压缩实验，扫描电镜观察材料断面：ELISA法测定不同时间点生理盐水中rhBMP-2浓度，计算rhBMP-2的累积释放量。材料植入小鼠大腿肌袋，术后3周处死小鼠，切取材料及周围组织，HE染色后进行组织学观察，同时测定材料周围组织中碱性磷酸酶及钙含量。结果：交联的明胶微球呈规则圆形，粒径（62±18）um，分散性好。1、3周后实验组材料断面可见大量大孔形成，对照组未见明显大孔，实验组的总孔径率、大孔率及rhBMP-2的累积释放量均高于对照组：3周后实验组最大压缩强度（7．8±1．2）MPa，较对照组（11.2±1．6）MPa稍低。HE染色两组均可见软骨形成，但实验组更多，碱性磷酸酶及钙含量测定实验组分别为（4.33±0．52）IU／g和（6．12±1.22）ug／mg，高于对照组的（2．67±0．23）IU／g和（3．12±0．41）ug／mg。结论：明胶微球／rhBMp-2／CPC在微球降解后形成多孔磷酸钙复合材料，使rhBMp2的释放量增加，具有强大的异位成骨性能，是一种优秀的骨组织工程材料。

Preparation and ectopic osteoinduction study of macroporous bone substitute with calcium phosphate cements and rhBMP-2 loaded gelatin microspheres

Objective:To prepare macroporous bone substitute composed of calcium phosphate cements and rhBMP 2 loaded gelatin microspheres,and to investigate ectopic osteoinduction of the composite.Methods:After being prepared by improved emulsified cold condensation method and crosslinked by 5% genipin solution,gelatin microspheres(GMs) were observed by scanning electron microscope(SEM) and loaded with rhBMP 2 by adsorption.Macroporous bone substitute was developed by mixing calcium phosphate cement(CPC) with 2.5% GMs...