重构Ⅰ型胶原联合聚天冬氨酸在仿骨生物矿化中的应用

Application of Recombinant Collagen Type Ⅰ Combined with Polyaspartic Acid in Biomimetic Biomineralization

目的重构Ⅰ型胶原联合聚天冬氨酸制备仿生物骨。方法采用酸解方法将鼠尾Ⅰ型胶原蛋白分解成原胶原纤维,然后置于钙磷矿化液中,在戊二醛交联下,重构组装成胶原纤维,并将钙磷晶体包裹在胶原纤维内部进行生物矿化。加入聚天冬氨酸,促进羟基磷灰石钙前体渗入胶原纤维内部,模仿人体内的骨生物矿化。矿化3d和9d,采用透射电子显微镜和电子衍射观察骨生物矿化过程。结果透射电子显微镜和电子衍射结果显示,矿化3d,羟基磷灰石钙前体被包裹在胶原纤维内部,胶原纤维部分矿化;矿化9d,羟基磷灰石前体完全渗入胶原蛋白纤维内部,其无定型磷酸钙状态最终转变成羟基磷灰石晶体,从而模拟完成骨生物矿化,形成Ⅰ型胶原蛋白/羟基磷灰石钙的仿生骨材料。结论重构Ⅰ型胶原联合聚天冬氨酸可制备出与人类自体骨组织化学成分和分子结构接近的仿生骨材料。

Objective To prepare biomimetic bone material by reconstructing type Ⅰ collagen combined with polyaspartic acid. Methods By acid hydrolysis,rat tail type Ⅰ collagen was decomposed into collagen fibers,which were then placed in the calcium phosphate mineralization solution. Under the cross-linking of glutaraldehyde,the collagen fibers were reconstructed and assembled into collagen fibers,and the calcium phosphate crystals were wrapped in the inner side of the collagen fibers for biomineralizationin. After poly aspartate acid was added,calcium hydroxyapatite calcium precursor was added into the collagen fibers to simulate thebiomimetic biomineralizationin the human body. After mineralization for 3-9 days,the bone mineralization process was observed by transmission electron microscopy and electron diffraction. Results Transmission electron microscopy and electron diffraction displayed that,after 3 days of mineralization,calcium hydroxyapatite precursorwas wrapped in the collagen fiber gap,and the collagen fiber was partially mineralized. After 9 days of mineralization,calcium hydroxyapatite precursor completely infiltrated into the collagen fiber,and the amorphous calcium phosphate was transformed into hydroxyapatite calcium crystal. Thus,the simulation of bone mineralization was completed, and collagen type Ⅰ collagen/hydroxyapatite calcium biomimetic bone material was formed.Conclusion Reconstruction of type Ⅰ collagen combined with polyaspartic acid can prepare biomimetic bone material that has close chemical composition and molecular structure to the human bone tissue.