仿生梯度可降解骨组织工程材料设计研究

发布时间：2018-11-04 09:14

【摘要】：骨缺损修复是目前临床中面临的难题之一，人们根据自体骨的结构研制了不同的仿生骨材料用以解决这一难题，但他们大部分致力于软骨的仿生研究，对硬组织的研究还很少见。因此，本课题旨在研究具备梯度可降解的复合仿生硬组织材料，使其具备与自体骨相似的结构及相匹配的力学性能。本文主要进行了以下两方面的工作：（1）选择羟基磷灰石为仿生松质骨原材料，通过微波烧结法制备出成分和结构均与自体骨相似的仿生松质骨，并对其生物活性进行测试；（2）选择纯镁为仿生皮质骨材料，首先对纯镁进行体内外降解实验，测试其生物可降解性以及生物骨诱导性，然后通过对纯镁的激光表面图案化处理来改善试样表面的生物活性，最后利用ANSYS软件对多孔镁板进行了力学性能测试。研究结果表明：（1）当烧结时的工艺参数为600W，15min时可制得由β-磷酸三钙（β-TCP）和羟基磷灰石（HA）两相组成的烧结产物；（2）在模拟体液（SBF）溶液中静态浸泡18d后，烧结后试样的表面及内部均形成类骨磷灰石，证明该试样具有良好的骨诱导性以及良好的孔连通性；（3）对纯镁试样进行体外生物性能研究时，将试样浸泡在SBF溶液中，试样的降解速度逐渐减慢，，并最终达到平衡。当浸泡20h后，表面有钙磷离子沉积，因此纯镁具有一定的生物活性；（4）对纯镁试样进行体内生物性能研究时，在植入动物体内后表现出良好的生物可降解性，但是由于氢气产生量过多以及试样的骨诱导性存在不足，导致在实验前期动物体出现不适现象；（5）通过激光表面图案化在纯镁试样表面制备出具有周期性的环形V凹槽微结构，经测试表明这种V型凹槽结构有利于钙磷离子的沉积，且起到了提高表面生物活性的作用；（6）通过拉伸试验证实了ANSYS软件对纯镁进行力学性能模拟的可靠性。经过ANSYS软件对多孔纯镁平板的力学性能模拟，模拟结果表明当孔数为60，即孔隙率为15.072%时试样可满足人体骨在变形方面的力学性能需求。
[Abstract]:Bone defect repair is one of the current clinical problems. Different biomimetic bone materials have been developed according to the structure of autogenous bone to solve this problem, but most of them are devoted to the biomimetic research of cartilage. The study of hard tissue is rare. Therefore, the purpose of this paper is to study the composite biomimetic hard tissue materials with gradient degradability, so that they have the same structure and matching mechanical properties as autogenous bone. The main work of this paper is as follows: (1) selecting hydroxyapatite as the raw material of biomimetic cancellous bone, biomimetic cancellous bone with similar composition and structure as autologous bone was prepared by microwave sintering, and its biological activity was tested. (2) selecting pure magnesium as biomimetic cortical bone material, the biodegradability and bone inductivity of pure magnesium were tested in vitro and in vivo. Then the surface bioactivity of pure magnesium was improved by laser patterning treatment. Finally, the mechanical properties of porous magnesium plate were tested by ANSYS software. The results show that: (1) when the sintering process parameter is 600W / L for 15 min, the sintered product composed of 尾 -tricalcium phosphate (尾-TCP) and hydroxyapatite (HA) can be prepared; (2) Bone-like apatite was formed on the surface and inside of the sintered sample after static immersion in simulated body fluid (SBF) solution for 18 days, which proved that the sample had good bone-induced property and good pore connectivity; (3) when the biological properties of pure magnesium samples were studied in vitro, the degradation rate of the samples gradually slowed down and finally reached equilibrium when the samples were immersed in SBF solution. After immersion for 20 hours, calcium and phosphorus ions were deposited on the surface, so pure magnesium had certain biological activity. (4) the biodegradability of pure magnesium sample was studied in vivo, but the hydrogen production was too much and the bone inductivity of the sample was insufficient. It leads to the discomfort of animals in the early stage of the experiment. (5) the circular V-groove microstructures with periodicity were prepared on the surface of pure magnesium by laser surface patterning. The results showed that the V-groove structure was favorable to the deposition of calcium and phosphorus ions and played a role in improving the surface biological activity. (6) the reliability of ANSYS software in simulating the mechanical properties of pure magnesium was confirmed by tensile test. The mechanical properties of porous pure magnesium plate were simulated by ANSYS software. The simulation results show that when the number of pores is 60, that is, the porosity is 15.072, the mechanical properties of human bone can be satisfied.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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