Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47908, USA.
J Biomed Mater Res A. 2010 Aug;94(2):547-55. doi: 10.1002/jbm.a.32742.
This study describes a novel method of calcium phosphate cement reinforcement based on infiltrating a pre-set cement with a reactive polymer and then cross-linking the polymer in situ. This method can be used to reinforce 3D calcium phosphate cement scaffolds, which we demonstrate using poly(ethylene glycol) diacrylate (PEGDA) as a model reinforcing polymer. The compressive strength of a 3D scaffold comprised of orthogonally intersecting beams was increased from 0.31 +/- 0.06 MPa to 1.65 +/- 0.13 MPa using PEGDA 600. In addition, the mechanical properties of reinforced cement were characterized using three PEGDA molecular weights (200, 400, and 600 Da) and three cement powder to liquid (P/L) ratios (0.8, 1.0, and 1.43). Higher molecular weight increased reinforcement efficacy, and P/L controlled cement porosity and determined the extent of polymer incorporation. Although increasing polymer incorporation resulted in a transition from brittle, cement-like behavior to ductile, polymer-like behavior, maximizing polymer incorporation was not advantageous. Polymerization shrinkage produced microcracks in the cement, which reduced the mechanical properties. The most effective reinforcement was achieved with P/L of 1.43 and PEGDA 600. In this group, flexural strength increased from 0.44 +/- 0.12 MPa to 7.04 +/- 0.51 MPa, maximum displacement from 0.05 +/- 0.01 mm to 1.44 +/- 0.17 mm, and work of fracture from 0.64 +/- 0.10 J/m(2) to 677.96 +/- 70.88 J/m(2) compared to non-reinforced controls. These results demonstrate the effectiveness of our novel reinforcement method, as well as its potential for fabricating reinforced 3D calcium phosphate cement scaffolds useful for bone tissue engineering.
本研究描述了一种基于在预设定的水泥中渗透反应性聚合物并原位交联聚合物的新型磷酸钙水泥增强方法。我们使用聚乙二醇二丙烯酸酯（PEGDA）作为模型增强聚合物来证明这种方法可用于增强 3D 磷酸钙水泥支架。使用正交相交梁组成的 3D 支架的抗压强度从 0.31 ± 0.06 MPa 增加到 1.65 ± 0.13 MPa 使用 PEGDA 600。此外，使用三种 PEGDA 分子量（200、400 和 600 Da）和三种水泥粉液比（0.8、1.0 和 1.43）对增强水泥的力学性能进行了表征。较高的分子量增加了增强效果，而 P/L 控制水泥的孔隙率并确定聚合物的掺入程度。虽然增加聚合物的掺入导致从脆性、水泥样行为转变为延性、聚合物样行为，但最大化聚合物的掺入并不有利。聚合收缩在水泥中产生微裂纹，从而降低了力学性能。在 P/L 为 1.43 和 PEGDA 600 的情况下，实现了最有效的增强。在该组中，弯曲强度从 0.44 ± 0.12 MPa 增加到 7.04 ± 0.51 MPa，最大位移从 0.05 ± 0.01 mm 增加到 1.44 ± 0.17 mm，断裂功从 0.64 ± 0.10 J/m 2增加到 677.96 ± 70.88 J/m 2与非增强对照相比。这些结果表明了我们新型增强方法的有效性，以及其用于制造用于骨组织工程的增强 3D 磷酸钙水泥支架的潜力。
