Preparation and Improvation of Nanophase Artificial Bone Composite Scaffold and Relevant Study on Properties

Objective:To prepare nanophase artificial bone composite scaffold based on bionics theory, and probe into how different content ratio between collagen and inorganic part as well as different molecular weight of conglutinant agent influence microstructure and properties of the scaffold. Methods: Lead calcic inorganic molecules to deposite onto self-assembled collagen template during coprecipitation under certain reactive conditions such as content ratio and pH value of environment, and then nanophase collagen/calcic salt is obtained. In order to improve the mechanical properties, poly lactic acid (PLLA) which has stable equal properties and controllable biodegradable activities is chosen as conglutinant agent, and then the aimed artificial bone scaffold (nanophase collagen/calcic salt/PLLA composite) is accomplished. After preparation liquid displacement method with isoproanol alcohol, scanning electron microscopic (SEM), transmission electron microscope (TEM), fourier transform infrared spectrometry (FTIR), mechanical testing system are performed to test porosity and density, morphology, conformation, composition and mechanical property, respectively.Results:The artificial synthesized bone composite scaffold is mainly composed of collagen and calcium phosphate partly displaced with B-type carbonate. The crystallinity is low,and the crystal size reaches nanometer which is similar to natural bone. PLLA used effectively improves the mechanical property which can reach at the floor level of cancellous standard,and develops three-dimensional-porous structure with high porosity of 80%. According to the comparison it can be seen that content ratio between collagen and calcic inorganic salt as well as addition of conglutinant PLLA all have an effect on microstructure of the synthesized scaffold, additionally molecular weight of PLLA has an effect on mechanical properties.Conclusion:The nanophase artificial bone composite scaffold synthesized by biomimetic process is one of the most promising optimal materials for clinical application no matter how judged from structure, composition and property.The various factors influencing the scaffold discussed in this article may indicate some useful modification ways according to the actual utility in the near future.