| Bone default repairing material is one of the hotspots of Biomaterial research. During the last ten years, Bone tissue engineering had been becoming the developing direction of this field for many of its merits. Tissue engineering involved the interaction of three biological factors including biologic matrix materials, cell and growth-gene. Among them, biologic matrix materials are the most important and difficult factor. Biologic matrix has been developed from bio-poly-materials or bioceramics only to bio-composites. Now, the bio- composites have been confirmed to be one of the developing directions of bone tissue engineering matrix materials. In order to make a kind of bone tissue engineering matrix material with favorable biocompatibility, mechanical properties and biodegradability, a process which consists of a solvent casting stage, a compression molding stage and a leaching stage had been used to fabricate macroporous composites of poly(l-lactic acid)(PLLA) and β-tricalcium phosphate(β-TCP) decorated by kittul acid. The mechanical properties and degradable characteristics of this material could be controlled by adjusting the components ratio and the porosity. The surface morphology of this material was observed by Scanning Electron Microscope(SEM), and mechanical properties were tested by almighty material testing machine. The degradability of this material was tested by Constant temperature Surging machine whose temperature can be adjusted, and biological properties were tested by cell fostering experiments at last. Based on these testing results, the effect mechanism of β-TCP/PLLA ratio, dosage of porogen and other factors on porosity and strength of the material had been discussed. The experimental results were listed below.1. It is found that the hydrophobic nature of β-TCP powder might been improved when decorated by kittul acid, but it did not affect the composites' properties remarkably.2. Different dosage of PLLA and β-TCP could affect the composites' properties. With the same other conditions, β-TCP:PLLA = 2:1, the composites possessed better advantages for molding and better mechanical properties. 3. When the ratio of PLLA and β-TCP was determined, with the increasing of the porogen dosage, the porosity would be increased, and the mechanical properties would be dropped down.4. The smaller composite particles was favorable to the molding of the composites. The material porosity could be different from 60% to 70% when poregen dosage addition was from 50% to 60%, and this porosity was suited with cell fostering. In a given range, the material properties would improve when molding temperature increased. Molding pressure did not affect the composites' properties remarkably. Accordingly, it could be seen that when the size of the materials for molding was 0.1~1.0mm, molding temperature was 130~160℃, molding pressure was 7~9 MPa, the porous composites could possess better properties correspondingly. 5. From the results of degradation experiments, it could be seen that with more PLLA given, or amount of β-TCP powder reduced, the speed of degrading increased. And the results showed that when β-TCP/PLLA was 2:1, the composites possessed mezzo degrading speed and higher mechanical strength, and its mechanical strength could be maintained for a long time. 6. From the results of cell fostering experiments, it could be seen that when β-TCP/PLLA was 2:1, the dosage addition of NaCl was 50%, the composites could provide a suitable environment for cell fostering.
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