Guo Ting, Holzberg Timothy R, Lim Casey G, Gao Feng, Gargava Ankit, Trachtenberg Jordan E, Mikos Antonios G, Fisher John P
The Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States of America.
Biofabrication. 2017 Apr 12;9(2):024101. doi: 10.1088/1758-5090/aa6370.
In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid:glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements.
在过去几十年中,3D打印在制造具有一致、复杂结构的支架方面发挥了重要作用,这些支架能够满足未来临床应用中患者的特定需求。尽管许多研究为这个新兴的增材制造领域做出了贡献,包括材料开发和计算机辅助支架设计,但目前的定量分析在很大程度上并未将材料特性、打印参数和打印结果关联起来。一个能够关联这些特性的模型对于组织工程和生物材料科学的3D打印标准化具有巨大潜力。在本研究中,我们使用直接熔融挤出技术打印聚乳酸-乙醇酸共聚物(PLGA),且不添加其他成分。我们研究了具有不同乳酸:乙醇酸(LA:GA)分子量比和封端的PLGA,以证明挤出过程对聚合物组成的依赖性。然后使用微型计算机断层扫描来评估包含不同LA:GA比例、由不同纤维图案组成且在不同打印条件下加工的打印支架。我们建立了一个统计模型来揭示决定打印精度的相关性和主要因素。我们的模型显示,在不同的打印条件和材料组成组合下,实际精度与预测精度之间存在很强的线性关系。这种定量研究为遵循系统制造程序的3D打印生物材料奠定了重要基础。此外,我们提出的统计模型可应用于将特定生物材料与具有特定要求的患者植入物的3D打印应用相结合。