Narra Nathaniel, Blanquer Sébastien B G, Haimi Suvi P, Grijpma Dirk W, Hyttinen Jari
Department of Electronics and Communications Engineering, Tampere University of Technology, BioMediTech Tampere, Finland.
Department of Biomaterials Science and Technology, University of Twente, Enschede, The Netherlands.
Clin Hemorheol Microcirc. 2015;60(1):99-108. doi: 10.3233/CH-151931.
Advances in rapid-prototyping and 3D printing technologies have enhanced the possibilities in preparing designed architectures for tissue engineering applications. A major advantage in custom designing is the ability to create structures with desired mechanical properties. While the behaviour of a designed scaffold can be simulated using bulk material properties, it is important to verify the behaviour of a printed scaffold at the microstructure level.
In this study we present an effective method in validating the mechanical behaviour of designed scaffolds using a μCT with an in-situ mechanical deformation device.
The scaffolds were prepared from biodegradable poly(trimethylene carbonate) (PTMC) by stereolithography and images obtained using a high-resolution μCT with 12.25μm isometric voxels. The data was processed (filtering, segmentation) and analysed (surface generation, registration) to extract relevant deformation features.
The computed local deformation fields, calculated at sub-pore resolutions, displayed expected linear behaviour within the scaffold along the compressions axis. On planes perpendicular to this axis, the deformations varied by 150- 200μm.
μCT based imaging with in-situ deformation provides a vital tool in validating the design parameters of printed scaffolds. Deformation fields obtained from micro-tomographic image volumes can serve to corroborate the simulated ideal design with the realized product.
快速成型和3D打印技术的进步增加了为组织工程应用制备设计架构的可能性。定制设计的一个主要优势是能够创建具有所需机械性能的结构。虽然可以使用块状材料特性模拟设计支架的行为，但在微观结构层面验证打印支架的行为很重要。
在本研究中，我们提出了一种使用带有原位机械变形装置的μCT验证设计支架机械行为的有效方法。
通过立体光刻从可生物降解的聚碳酸三亚甲基酯（PTMC）制备支架，并使用具有12.25μm等距体素的高分辨率μCT获得图像。对数据进行处理（滤波、分割）和分析（表面生成、配准）以提取相关变形特征。
在亚孔隙分辨率下计算的局部变形场在支架内沿压缩轴显示出预期的线性行为。在垂直于该轴的平面上，变形变化为150 - 200μm。
基于μCT的原位变形成像为验证打印支架的设计参数提供了重要工具。从微观断层图像体积获得的变形场可用于将模拟的理想设计与实际产品进行对比。
