一种具有骨诱导活性的羟基磷灰石结晶的制备与研究

目的将骨形成蛋白2（BMP2）活性多肽与Ⅰ型胶原复合煅烧牛松质骨以制备出具有骨诱导活性的矿化羟基磷灰石结晶,并进一步探讨其生物学性能,为组织工程化人工骨提供实验基础。方法将BMP2活性多肽与Ⅰ型胶原复合煅烧牛松质骨作为实验组,以Ⅰ型胶原复合煅烧牛松质骨作为对照组。通过环境扫描电镜和能谱法以及x射线衍射实验观察能否生成羟基磷灰石结晶,同时对2组材料进行体外细胞培养,计算2组材料细胞黏附率,初步评价BMP2活性多肽引导Ⅰ型胶原复合煅烧牛松质骨表面矿化生成羟基磷灰石结晶的作用与能力。结果环境扫描电镜下可见实验组煅烧骨表面有矿化羟基磷灰石结晶生成,而对照组没有：能谱法对实验组矿化骨部分进行钙磷元素检测,质量比分别为16．23％、7．76％．原子百分数分别为6．34％、3．88％,X射线衍射检测证实矿化物的成分为磷灰石。大鼠骨髓基质干细胞分别与2组材料体外复合培养24h,实验组细胞黏附率明显高于对照组（a〈0．05）。结论BMP2活性多肽能引导Ⅰ型胶原复合煅烧骨表面矿化生成羟基磷灰石结晶,可以改善煅烧骨的骨诱导活性,提高细胞黏附性能,与煅烧骨复合后是一种理想的骨组织支架复合材料。

Preparation and characterization of oligopeptide modified hydroxyapatite crystal scaffolds

Objective To prepare a new osteoinduction hydroxyapatite crystal material using sintered bovine bone combined with bone morphogenetic protein(BMP2)-derived peptide and type Ⅰ collagen,and to study their biological characteristics for developing biomaterials for orthopaedic tissue engineered bone.Methods Sintered bovine bone combined with BMP2-derived peptide and type Ⅰ collagen was as experimental group.and Sintered bovine bone combined with Type Ⅰ collagen Wag as control group.Formation of hydmxyapatite crystals was inveati gated under environmental scanning electron microscopy(ESEM),energy-dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The ceil-material complex Wag observed and cell adhesion rate on each materials WaS calculated using the method of indirect cell count to evaluate the interaction between cells and materials.Results By ESEM,formation of hydroxyapatite crystals in collagen surface was observed in experimental group but none was observed in control group.By EDS and XRD,the contents of calcium and phosphorus elements from mineralized bone surface were 16.23% and 7.76%respectively.The atom percentages of calcium and phosphorus elements were 6.34%and 3.88%respectively.The cell adhesion rate of experimental group after 24 hours co-culture was significantly higher than that of control group (α＜0.05).Conclusion BMP2-derived peptide can induce the formation of hydroxyapatite crystals at the surface of sintered bovine bone combined with type Ⅰcollagen.It can also elevate the osteoinduction and cell adhesion rate and is an ideal scaffold material by combining with sintered bovine bone for the bone tissue engineering.