University of Illinois at Urbana-Champaign Department of Bioengineering, 1102 Everitt Lab, MC-278, 1406 W. Green Street, Urbana, IL, 61801, USA.
University of Illinois at Urbana-Champaign Department of Mechanical Science and Engineering, Mechanical Engineering Building, 1206 W. Green St. MC 244, Urbana, IL, 61801, USA.
Adv Healthc Mater. 2021 Jun;10(12):e2100223. doi: 10.1002/adhm.202100223. Epub 2021 Apr 23.
3D microenvironments provide a unique opportunity to investigate the impact of intrinsic mechanical signaling on progenitor cell differentiation. Using a hydrogel-based microwell platform, arrays of 3D, multicellular microtissues in constrained geometries, including toroids and cylinders are produced. These generated distinct mechanical profiles to investigate the impact of geometry and stress on early liver progenitor cell fate using a model liver development system. Image segmentation allows the tracking of individual cell fate and the characterization of distinct patterning of hepatocytic makers to the outer shell of the microtissues, and the exclusion from the inner diameter surface of the toroids. Biliary markers are distributed throughout the interior regions of micropatterned tissues and are increased in toroidal tissues when compared with those in cylindrical tissues. Finite element models of predicted stress distributions, combined with mechanical measurements, demonstrates that intercellular tension correlates with increased hepatocytic fate, while compression correlates with decreased hepatocytic and increased biliary fate. This system, which integrates microfabrication, imaging, mechanical modeling, and quantitative analysis, demonstrates how microtissue geometry can drive patterning of mechanical stresses that regulate cell differentiation trajectories. This approach may serve as a platform for further investigation of signaling mechanisms in the liver and other developmental systems.
3D 微环境为研究内在机械信号对祖细胞分化的影响提供了独特的机会。使用基于水凝胶的微井平台，可以在受限的几何形状中产生 3D 多细胞微组织的阵列，包括环和圆柱。这些生成的不同机械轮廓用于使用模型肝脏发育系统研究几何形状和应力对早期肝祖细胞命运的影响。图像分割允许跟踪单个细胞命运，并对微组织外表面的肝细胞标志物的不同模式进行特征化，以及从环的内径表面排除。胆管标记物分布在微图案化组织的内部区域中，并且在与圆柱组织相比时，在环组织中增加。结合力学测量的预测应力分布的有限元模型表明，细胞间张力与增加的肝细胞命运相关，而压缩与减少的肝细胞和增加的胆管命运相关。该系统集成了微制造、成像、力学建模和定量分析，展示了微组织几何形状如何驱动调节细胞分化轨迹的机械应力的模式形成。这种方法可以作为进一步研究肝脏和其他发育系统中信号机制的平台。
