Hsu Chia-Chen, George Julian H, Waller Sharlayne, Besnard Cyril, Nagel David A, Hill Eric J, Coleman Michael D, Korsunsky Alexander M, Cui Zhanfeng, Ye Hua
Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK.
MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
Bioact Mater. 2021 Jul 15;9:358-372. doi: 10.1016/j.bioactmat.2021.07.008. eCollection 2022 Mar.
To reflect human development, it is critical to create a substrate that can support long-term cell survival, differentiation, and maturation. Hydrogels are promising materials for 3D cultures. However, a bulk structure consisting of dense polymer networks often leads to suboptimal microenvironments that impedes nutrient exchange and cell-to-cell interaction. Herein, granular hydrogel-based scaffolds were used to support 3D human induced pluripotent stem cell (hiPSC)-derived neural networks. A custom designed 3D printed toolset was developed to extrude hyaluronic acid hydrogel through a porous nylon fabric to generate hydrogel granules. Cells and hydrogel granules were combined using a weaker secondary gelation step, forming self-supporting cell laden scaffolds. At three and seven days, granular scaffolds supported higher cell viability compared to bulk hydrogels, whereas granular scaffolds supported more neurite bearing cells and longer neurite extensions (65.52 ± 11.59 μm) after seven days compared to bulk hydrogels (22.90 ± 4.70 μm). Long-term (three-month) cultures of clinically relevant hiPSC-derived neural cells in granular hydrogels supported well established neuronal and astrocytic colonies and a high level of neurite extension both inside and beyond the scaffold. This approach is significant as it provides a simple, rapid and efficient way to achieve a tissue-relevant granular structure within hydrogel cultures.
为了反映人类发育情况，创建一个能够支持细胞长期存活、分化和成熟的基质至关重要。水凝胶是用于三维培养的有前景的材料。然而，由致密聚合物网络组成的块状结构通常会导致微环境欠佳，阻碍营养物质交换和细胞间相互作用。在此，基于颗粒水凝胶的支架被用于支持三维人诱导多能干细胞（hiPSC）衍生的神经网络。开发了一种定制设计的三维打印工具集，通过多孔尼龙织物挤出透明质酸水凝胶以生成水凝胶颗粒。细胞和水凝胶颗粒通过较弱的二次凝胶化步骤结合，形成自支撑的载细胞支架。在三天和七天时，与块状水凝胶相比，颗粒支架支持更高的细胞活力，而在七天后，与块状水凝胶（22.90±4.70μm）相比，颗粒支架支持更多带有神经突的细胞和更长的神经突延伸（65.52±11.59μm）。在颗粒水凝胶中对临床相关的hiPSC衍生神经细胞进行长期（三个月）培养，支持了支架内外成熟的神经元和星形胶质细胞集落以及高水平的神经突延伸。这种方法意义重大，因为它提供了一种简单、快速且高效的方式，在水凝胶培养物中实现与组织相关的颗粒结构。
