原位凝固成型法制备可控孔隙结构β-磷酸三钙组织工程支架的研究

发布时间：2018-06-14 10:20

本文选题：β-磷酸三钙 + 骨组织工程支架　；参考：《华南理工大学》2012年硕士论文

【摘要】：理想的组织工程支架要求具有三维连通的孔隙结构和一定的力学强度。传统的造孔方法对孔径大小和连通程度的可控性差，近年来新兴的快速原型制造技术精度高，，能够很好地成型复杂形状零件，具备控制骨组织工程支架结构的能力，但是目前快速原型技术只能对部分生物惰性的高分子材料进行成型。本研究采用快速原型技术，结合凝胶注模成型工艺淀粉原位凝固技术制备了可控孔隙结构的β-磷酸三钙骨组织工程修复支架。本研究以制备可控孔隙结构的β-磷酸三钙骨组织工程修复支架为目的，探讨和优化了支架制备工艺流程。通过对浆料流变性能的检测，确定分散剂聚丙烯酸钠加入量为1wt%，凝固剂淀粉加入量为1.5wt%所配置的固相含量为50%(V/V)的β-磷酸三钙浆料具有较低的粘度，符合凝胶注模成型工艺对浆料的要求。采用快速原型技术构造了三种不同形貌的高分子多孔模板，并进一步通过浆料灌注和凝胶注模淀粉原位凝固技术制备出以β-磷酸三钙为主要成分的三维多孔支架，实现了对骨组织工程支架孔结构的控制。采用微计算机断层扫描技术，在不破坏样品的情况下，精确地对支架的孔隙结构进行了观察和表征，并对支架的物相组成、显微形貌以及抗压强度进行了分析和测试。采用高分子模板制备的规则孔结构支架，大孔隙相互连通构成三维连通结构，并且具有大孔-微孔多级孔结构，抗压强度可达2MPa以上，大孔孔隙率为50%以上。结果表明，通过快速原型技术制备的连通多孔高分子模板，结合原位凝固成型技术，可以制备出孔径和结构可控、孔隙完全连通的β-磷酸三钙支架。其中采用高分子模板B制备的规则孔结构支架B，大孔孔径尺寸约为800m，平均压缩强度为2.21±0.36MPa，大孔孔隙率为53.2%。本研究利用灌注-冷冻干燥技术和真空镀膜技术，采用三种具有良好生物相容性的高分子材料(壳聚糖、明胶和PLGA)与β-磷酸三钙多孔支架进行了复合，以达到增强多孔支架的力学性能，改善支架大孔结构的目的。实验表明，采用灌注-冷冻干燥技术制备的复合支架大孔结构被填充。采用真空镀膜技术制备的复合支架可以在无机支架骨架上覆盖一层薄膜。在力学性能方面，相比于原无机支架，复合后支架的韧性均得到了很大改善。其中，采用PLGA复β-TCP无机支架，保留了原来的大孔结构，复合支架抗压强度能达到2.25±0.15MPa，形变量可达30%。明胶/β-磷酸三钙多孔支架能够获得较好的力学性能，其抗压强度可达到3.18±0.55MPa，形变量可达50%。所制备的支架基本上能够满足非承重部位骨缺损修复的要求，有望经进一步改善后应用于临床。
[Abstract]:An ideal scaffold for tissue engineering requires a three-dimensional connected pore structure and a certain mechanical strength. The traditional method of hole making has poor controllability to the aperture size and connectivity. The newly developed rapid prototyping manufacturing technology has high precision and can be used to shape the parts with complex shape and has the ability to control the scaffold structure of bone tissue engineering. But at present, rapid prototyping technology can only form some biologically inert polymer materials. In this study, the 尾 -tricalcium phosphate bone tissue engineering scaffold with controllable pore structure was prepared by rapid prototyping and starch in-situ solidification. In order to prepare 尾 -tricalcium phosphate bone tissue engineering scaffolds with controllable pore structure, the preparation process of the scaffolds was discussed and optimized. By testing the rheological properties of the slurry, it was determined that the 尾 -tricalcium phosphate slurry with dispersing agent sodium polyacrylate and coagulant starch with solid content of 50 V / V) had low viscosity, and the content of coagulant starch was 1.5 wt%. In accordance with the gel injection molding process for slurry requirements. Three kinds of macromolecule porous templates with different morphologies were constructed by rapid prototyping technique. Furthermore, three dimensional porous scaffolds with 尾 -tricalcium phosphate as the main component were prepared by slurry pouring and gel injection starch in-situ solidification. The structure of scaffold hole in bone tissue engineering is controlled. The pore structure of the scaffold was observed and characterized accurately by means of microcomputed tomography without destroying the sample. The phase composition, microstructure and compressive strength of the scaffold were analyzed and tested. The regular pore structure scaffold prepared by macromolecule template is connected with each other to form a three-dimensional connected structure, and has a macroporous and microporous multistage pore structure, the compressive strength can reach more than 2 MPA, and the porosity of macropore is more than 50%. The results showed that the porous polymer template prepared by rapid prototyping, combined with in-situ solidification technology, could be used to prepare 尾 -tricalcium phosphate scaffolds with controllable pore size and structure and complete connectivity of pores. The regular pore structure scaffold B prepared by polymer template B has a pore size of about 800 m, an average compression strength of 2.21 卤0.36 MPa and a porosity of 53.22MPa. In this study, three kinds of polymer materials (chitosan, gelatin and PLGA) with good biocompatibility were used to combine 尾 -tricalcium phosphate porous scaffold with perfusion freeze-drying and vacuum coating technology. In order to enhance the mechanical properties of porous scaffolds and improve the structure of macroporous scaffolds. The experimental results show that the macroporous structure of composite scaffold prepared by perfusion-freeze-drying technique is filled. The composite scaffolds prepared by vacuum coating technology can be coated on the inorganic scaffold skeleton. In terms of mechanical properties, compared with the original inorganic scaffold, the toughness of the composite scaffold has been greatly improved. Among them, PLGA complex 尾 -TCP inorganic scaffolds retain the original macroporous structure, the compressive strength of the composite scaffold can reach 2.25 卤0.15 MPA, and the shape variable can reach 30 parts. The gelatin / 尾 -tricalcium phosphate porous scaffold can obtain better mechanical properties, its compressive strength can reach 3.18 卤0.55 MPA, and the shape variable can reach 50 MPA. The scaffold can basically meet the requirements of bone defect repair in non-load-bearing site, and it is expected to be used in clinical practice after further improvement.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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