Fabrication and characterization of poly(propylene fumarate) scaffolds with controlled pore structures using 3-dimensional printing and injection molding
Fabrication and characterization of poly(propylene fumarate) scaffolds with controlled pore structures using 3-dimensional printing and injection molding
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DOI：
10.1089/ten.2006.12.2801
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发表时间：
2006-10-01
影响因子：
--
通讯作者：
Yaszemski, Michael J.
中科院分区：
文献类型：
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作者：
Lee, Kee-Won;Wang, Shanfeng;Yaszemski, Michael J.
聚（富马酸丙二醇酯）（PPF）是一种可注射、可生物降解的聚合物，由于其原位交联特性，已被用于制备组织工程应用中的预成型支架。为了了解孔结构参数对骨组织长入的影响，本研究从计算机辅助设计（CAD）模型中制作了具有受控孔结构的三维（3D）PPF支架。我们已经创建了具有3个孔径（300、600和900 μ m）的原始支架模型，并且在3个平面中随机封闭来自原始模型的总孔的0%、10%、20%或30%。PPF支架通过一系列步骤制造，包括3D打印支撑/构建结构、溶解构建材料、注射PPF和溶解支撑材料。为了研究控制孔径和互连性对支架的影响，我们比较了模型和由此制造的PPF支架之间的孔隙率，使用扫描电子显微镜检查表面和横截面的孔形态，并使用落头电导率测试测量渗透性。通过差示扫描量热法和热重分析测定所得支架以及未交联的PPF的热性能。PPF支架的平均孔径和孔形状与600-和900-μ m的孔相似的CAD模型，但它们依赖于那些与300-μ m的孔的方向。PPF支架的孔隙率和渗透性随着原始模型中闭孔数量的增加而降低，特别是当孔径为300 μ m时，这是低孔隙率和孔闭塞的结果。这些结果表明，3D打印和注射成型技术可以应用于可交联聚合物，以使用其CAD模型制造具有受控孔结构、孔隙率和渗透性的3D多孔支架。
Poly(propylene fumarate) (PPF) is an injectable, biodegradable polymer that has been used for fabricating preformed scaffolds in tissue engineering applications because of in situ crosslinking characteristics. Aiming for understanding the effects of pore structure parameters on bone tissue ingrowth, 3-dimensional (3D) PPF scaffolds with controlled pore architecture have been produced in this study from computer-aided design (CAD) models. We have created original scaffold models with 3 pore sizes (300, 600, and 900 mu m) and randomly closed 0%, 10%, 20%, or 30% of total pores from the original models in 3 planes. PPF scaffolds were fabricated by a series steps involving 3D printing of support/build constructs, dissolving build materials, injecting PPF, and dissolving support materials. To investigate the effects of controlled pore size and interconnectivity on scaffolds, we compared the porosities between the models and PPF scaffolds fabricated thereby, examined pore morphologies in surface and cross-section using scanning electron microscopy, and measured permeability using the falling head conductivity test. The thermal properties of the resulting scaffolds as well as uncrosslinked PPF were determined by differential scanning calorimetry and thermogravimetric analysis. Average pore sizes and pore shapes of PPF scaffolds with 600- and 900-mu m pores were similar to those of CAD models, but they depended on directions in those with 300-mu m pores. Porosity and permeability of PPF scaffolds decreased as the number of closed pores in original models increased, particularly when the pore size was 300 mu m as the result of low porosity and pore occlusion. These results show that 3D printing and injection molding technique can be applied to crosslinkable polymers to fabricate 3D porous scaffolds with controlled pore structures, porosity, and permeability using their CAD models.