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

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 precursor was 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.