Neural progenitor cell (NPC) culture within three-dimensional (3D) hydrogels is an attractive strategy for expanding a therapeutically relevant number of stem cells. However, relatively little is known about how 3D material properties such as stiffness and degradability affect the maintenance of NPC stemness in the absence of differentiation factors. Over a physiologically relevant range of stiffness from ∼0.5 to 50 kPa, stemness maintenance did not correlate with initial hydrogel stiffness. In contrast, hydrogel degradation was both correlated with, and necessary for, maintenance of NPC stemness. This requirement for degradation was independent of cytoskeletal tension generation and presentation of engineered adhesive ligands, instead relying on matrix remodelling to facilitate cadherin-mediated cell–cell contact and promote β-catenin signalling. In two additional hydrogel systems, permitting NPC-mediated matrix remodelling proved to be a generalizable strategy for stemness maintenance in 3D. Our findings have identified matrix remodelling, in the absence of cytoskeletal tension generation, as a previously unknown strategy to maintain stemness in 3D.

三维 (3D) 水凝胶内的神经祖细胞 (NPC) 培养是扩大治疗相关数量的干细胞的有吸引力的策略。然而，在没有分化因子的情况下，关于 3D 材料特性（如刚度和可降解性）如何影响 NPC 干性的维持知之甚少。在生理相关的刚度范围内，从∼0.5 至 50 kPa，干性维持与初始水凝胶刚度无关。相比之下，水凝胶降解与 NPC 干性的维持相关，也是必要的。这种降解要求与细胞骨架张力的产生和工程粘附配体的呈现无关，而是依赖于基质重塑来促进钙粘蛋白介导的细胞-细胞接触并促进 β-连环蛋白信号传导。在另外两个水凝胶系统中，允许 NPC 介导的基质重塑被证明是 3D 中干性维持的可推广策略。我们的研究结果已经确定了基质重塑，在没有细胞骨架张力产生的情况下，作为一种以前未知的维持 3D 干性的策略。