title: Automated quantitative assessment of three-dimensional bioprinted hydrogel scaffolds using optical coherence tomography.
abstract: Reconstructing and quantitatively assessing the internal architecture of opaque three-dimensional (3D) bioprinted hydrogel scaffolds is difficult but vital to the improvement of 3D bioprinting techniques and to the fabrication of functional engineered tissues. In this study, swept-source optical coherence tomography was applied to acquire high-resolution images of hydrogel scaffolds. Novel 3D gelatin/alginate hydrogel scaffolds with six different representative architectures were fabricated using our 3D bioprinting system. Both the scaffold material networks and the interconnected flow channel networks were reconstructed through volume rendering and binarisation processing to provide a 3D volumetric view. An image analysis algorithm was developed based on the automatic selection of the spatially-isolated region-of-interest. Via this algorithm, the spatially-resolved morphological parameters including pore size, pore shape, strut size, surface area, porosity, and interconnectivity were quantified precisely. Fabrication defects and differences between the designed and as-produced scaffolds were clearly identified in both 2D and 3D; the locations and dimensions of each of the fabrication defects were also defined. It concludes that this method will be a key tool for non-destructive and quantitative characterization, design optimisation and fabrication refinement of 3D bioprinted hydrogel scaffolds. Furthermore, this method enables investigation into the quantitative relationship between scaffold structure and biological outcome.
authors.affiliation: College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; Key Laboratory of Medical Information and 3D Bioprinting of Zhejiang Province, Hangzhou Dianzi University, Hangzhou 310018, China; lingw@hdu.edu.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; Key Laboratory of Medical Information and 3D Bioprinting of Zhejiang Province, Hangzhou Dianzi University, Hangzhou 310018, China; Hangzhou Regenovo Corporation, Hangzhou 310018, China; xumingen@hdu.edu.cn.
authors.forename: Mingen
authors.initials: M
authors.lastname: Xu
authors.affiliation: College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
authors.forename: LieLie
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; Key Laboratory of Medical Information and 3D Bioprinting of Zhejiang Province, Hangzhou Dianzi University, Hangzhou 310018, China.
authors.forename: QingQing
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
authors.forename: Li
authors.initials: L
authors.lastname: Luo
keywords: (170.3880) Medical and biological imaging; (170.4500) Optical coherence tomography