Centre for Translational Bone, Joint and Soft Tissue Research, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
Biofabrication. 2022 Sep 27;14(4). doi: 10.1088/1758-5090/ac9019.
liver models allow the investigation of the cell behavior in disease conditions or in response to changes in the microenvironment. A major challenge in liver tissue engineering is to mimic the tissue-level complexity: besides the selection of suitable biomaterial(s) replacing the extracellular matrix (ECM) and cell sources, the three-dimensional (3D) microarchitecture defined by the fabrication method is a critical factor to achieve functional constructs. In this study, coaxial extrusion-based 3D bioprinting has been applied to develop a liver sinusoid-like model that consists of a core compartment containing pre-vascular structures and a shell compartment containing hepatocytes. The shell ink was composed of alginate and methylcellulose (algMC), dissolved in human fresh frozen plasma. The algMC blend conferred high printing fidelity and stability to the core-shell constructs and the plasma as biologically active component enhanced viability and supported cluster formation and biomarker expression of HepG2 embedded in the shell. For the core, a natural ECM-like ink based on angiogenesis-supporting collagen-fibrin (CF) matrices was developed; the addition of gelatin (G) enabled 3D printing in combination with the plasma-algMC shell ink. Human endothelial cells, laden in the CFG core ink together with human fibroblasts as supportive cells, formed a pre-vascular network in the core in the absence and presence of HepG2 in the shell. The cellular interactions occurring in the triple culture model enhanced the albumin secretion. In conclusion, core-shell bioprinting was shown to be a valuable tool to study cell-cell-interactions and to develop complex tissue-like models.
肝脏模型允许研究细胞在疾病条件下或对微环境变化的反应中的行为。肝脏组织工程的主要挑战是模拟组织水平的复杂性：除了选择合适的生物材料替代细胞外基质 (ECM) 和细胞来源外，制造方法定义的三维 (3D) 微结构是实现功能性构建体的关键因素。在这项研究中，基于同轴挤出的 3D 生物打印已被应用于开发一种类似于肝窦的模型，该模型由包含前血管结构的核心腔室和包含肝细胞的壳腔室组成。壳墨由藻酸盐和甲基纤维素 (algMC) 组成，溶解在人新鲜冷冻血浆中。algMC 共混物赋予了核心-壳结构和作为生物活性成分的血浆高打印保真度和稳定性，增强了嵌入壳中的 HepG2 的活力，并支持其集群形成和生物标志物表达。对于核心，开发了一种基于支持血管生成的胶原蛋白-纤维蛋白 (CF) 基质的天然 ECM 样墨水；添加明胶 (G) 可与血浆-algMC 壳墨一起进行 3D 打印。载有人内皮细胞和人成纤维细胞作为支持细胞的 CFG 核心墨水中形成了一个前血管网络，而 HepG2 则存在于壳中。三重培养模型中发生的细胞相互作用增强了白蛋白的分泌。总之，核心-壳生物打印被证明是研究细胞-细胞相互作用和开发复杂组织样模型的有价值的工具。
