Preparation Of Homogeneous Hydroxyapatite/Organic Macromolecule Composite For Bone Repair Materials

In this research, in situ preparation and microemulsion techniques were originally used to prepare the Hydroxyapatite (HAp)/Chitosan (CS) and HAp/Polylactic acid (PLA) homogeneous composites. And the point was to find out the new approaches that could improve the distribution of the HAp particles in the matrix and the compatibility of the interphase boundary.Considering the principles that calcium phosphate salts have different solubility with diverse pH value and the function of selectivity pervasion of ions of CS film, a HAp/chitosan composite scaffold was developed. The HAp particles were made in situ through a rehydration with alkaline solution and dispersed homogeneously on the porous scaffold. They bounded to the CS scaffolds very well. The effects of the rehydration time, the concentration of CS solution, the content of HAp and collagen on the composition, structure, properties and bioactivity of the composite scaffolds were studied. On the other hand, the test of the proliferation ability of cells, observation the morphology of the cells and in vivo implant test were studied to evaluate the biocompatibility. Results showed that as the ratio of inorganic/organic was 60:100, the inorganic phase of the composite was HAp after 24h rehydration. And the porosity and pore size of composite decreased while the compress strength increased as the concentration of CS solution enhanced. When the concentration of CS solution was 2%, pore size of composite was about 200-800μm, and HAp particles were claviform with 15μm in length. The compress strength of the homogeneous composite scaffolds enhanced as the content of HAp increased, as well as the porosity of the homogeneous composite scaffolds was above 85%. When the ratio of inorganic/organic was 60:100, the homogeneous composite scaffolds of HAp/CS and HAp/CS/COL had higher porosity and compress strength though higher weight loss comparing to those of the composites scaffold prepared by mechanical blending. SEM and EDS results showed that HAp particles of the homogeneous composites were not only scattered more even than the composites prepared by mechanical blending, but also bounded to the CS matrix more well. The bioactivity and biocompatibility test,...