Bioresource Processing Research Institute of Australia (BioPRIA), Department of Chemical Engineering, Monash University, Australia.
Development and Stem Cells Program, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia.
Mater Sci Eng C Mater Biol Appl. 2021 May;124:112051. doi: 10.1016/j.msec.2021.112051. Epub 2021 Mar 24.
Three-dimensional (3D) cell culture systems include bioengineered microenvironments that mimic the complexity of human tissues and organs in vitro. Robust biological models, like organoids and spheroids, rely on biomaterials to emulate the biochemical and biomechanical properties found in the extracellular matrix (ECM). Collagen (COL) is the main protein component of the ECM and has been used to generate fibrous matrices for 3D cell culture. Whilst neat COL gels are commonly blended with inert polymers to improve their poor mechanical properties, whether nanocellulose (NC) fibers interact or can develop some synergic bioactive effect to support organoid systems has never been demonstrated. Here, we investigate collagen-nanocellulose (COL-NC) hydrogels as a thermo-responsive matrix for the formation and growth of intestinal organoids. Cellulose nanofibres grafted with fibronectin-like adhesive sites form a porous network with type I collagen, presenting a sol-gel transition and viscoelastic profile similar to those of standard animal-based matrices. Crypts embedded in COL-NC form organoids with evidence of epithelial budding. Cell viability and metabolic activity are preserved as well as the expression of key cell markers. The stiffness of COL-NC hydrogels is shown to be a determinant element for the formation and development organoids. COL-NC hydrogels provide an affordable, performant thermo-responsive and sustainable matrix for organoid growth.
三维（3D）细胞培养系统包括生物工程微环境，可在体外模拟人体组织和器官的复杂性。像类器官和球体这样的强大生物模型依赖于生物材料来模拟细胞外基质（ECM）中发现的生化和生物力学特性。胶原蛋白（COL）是 ECM 的主要蛋白质成分，已被用于生成用于 3D 细胞培养的纤维基质。虽然纯 COL 凝胶通常与惰性聚合物混合以改善其较差的机械性能，但纳米纤维素（NC）纤维是否相互作用或能否产生一些协同的生物活性效应来支持类器官系统从未得到证明。在这里，我们研究了胶原-纳米纤维素（COL-NC）水凝胶作为用于肠类器官形成和生长的热响应基质。接枝有纤维连接蛋白样粘附位点的纤维素纳米纤维与 I 型胶原蛋白形成多孔网络，呈现出类似于标准动物基质的溶胶-凝胶转变和粘弹性特征。嵌入 COL-NC 中的隐窝形成具有上皮芽生证据的类器官。细胞活力和代谢活性得以保留，关键细胞标志物的表达也得以保留。COL-NC 水凝胶的刚度被证明是类器官形成和发育的决定因素。COL-NC 水凝胶为类器官的生长提供了一种经济实惠、性能良好、热响应和可持续的基质。
