光学相干层析成像技术用于三维生物打印水凝胶支架结构的定量评价研究

Quantitative Evaluation of Three-Dimensional Bio-Printed Hydrogel Scaffolds by Optical Coherence Tomography

三维生物打印水凝胶支架内部结构的无损检测分析,对组织工程支架设计制造和生物功能实现具有重要意义。提出用扫频光学相干层析成像技术(SS-OCT)对三维生物打印的水凝胶支架进行无损成像和定量分析。设计和打印了4种代表性结构的三维水凝胶支架。用高分辨SS-OCT成像系统重建并揭示了支架内部三维结构,识别出打印支架与设计结构的差异以及孔融合、孔变形、通道堵塞等打印缺陷。基于阈值分割和形态操作的自动分析算法,定量表征了支架的孔隙大小及分布、实体支撑尺寸、孔隙率和三维连通性等结构参数。研究证明,OCT技术可以为三维生物打印水凝胶支架的优化设计、过程控制、功能分析提供有力工具。

Nondestructive investigation and analysis of the internal structure of three-dimensional（3D） bio-printed hydrogel scaffolds is very important for the design, fabrication, and biological functions of engineered tissue scaffolds. Swept- source optical coherence tomography（SS- OCT） is applied to nondestructive imaging and quantitative analysis of 3D bio-printed hydrogel scaffolds. 3D bio-printing technique is used to produce four representative designed geometries of hydrogel scaffolds. High-resolution SS-OCT visualizes the three-dimensional internal structure of the scaffolds, identifies the difference between the designed model and as- produced construction, and detects the printed defects such as fused pores, deformation of pores, breakages of flow channels.The automatic imaging analysis algorithms are developed to quantitatively characterize the pore size（PS） and its distribution, strut size（St S）, volume porosity（VP）, and pore interconnectivity（PC）. It concludes that OCT may be a key tool for the design optimization, process refinement, function realization of 3D bio-printed hydrogel scaffolds.