Chen Zhi, Liu Xiao, You Jingjing, Song Yihui, Tomaskovic-Crook Eva, Sutton Gerard, Crook Jeremy M, Wallace Gordon G
ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, AIIM Facility, Innovation Campus, University of Wollongong, Fairy Meadow, New South Wales 2519, Australia.
Save Sight Institute, University of Sydney, Sydney, New South Wales 2000, Australia.
Acta Biomater. 2020 Sep 1;113:360-371. doi: 10.1016/j.actbio.2020.07.004. Epub 2020 Jul 8.
Engineering substantia propria (or stroma of cornea) that mimics the function and anatomy of natural tissue is vital for in vitro modelling and in vivo regeneration. There are, however, few examples of bioengineered biomimetic corneal stroma. Here we describe the construction of an orthogonally oriented 3D corneal stroma model (3D-CSM) using pure electro-compacted collagen (EC). EC films comprise aligned collagen fibrils and support primary human corneal stromal cells (hCSCs). Cell-laden constructs are analogous to the anatomical structure of native human cornea. The hCSCs are guided by the topographical cues provided by the aligned collagen fibrils of the EC films. Importantly, the 3D-CSM are biodegradable, highly transparent, glucose-permeable and comprise quiescent hCSCs. Gene expression analysis indicated the presence of aligned collagen fibrils is strongly coupled to downregulation of active fibroblast/myofibroblast markers α-SMA and Thy-1, with a concomitant upregulation of the dormant keratocyte marker ALDH3. The 3D-CSM represents the first example of an optimally robust biomimetic engineered corneal stroma that is constructed from pure electro-compacted collagen for cell and tissue support. The 3D-CSM is a significant advance for synthetic corneal stroma engineering, with the potential to be used for full-thickness and functional cornea replacement, as well as informing in vivo tissue regeneration. STATEMENT OF SIGNIFICANCE: This manuscript represents the first example of a robust, transparent, glucose permeable and pure collagen-based biomimetic 3D corneal stromal model (3D-CSM) constructed from pure electro-compacted collagen. The collagen fibrils of 3D-CSM are aligned and orthogonally arranged, mimicking native human corneal stroma. The alignment of collagen fibrils correlates with the direction of current applied for electro-compaction and influences human corneal stromal cell (hCSC) orientation. Moreover, 3D-CSM constructs support a corneal keratocyte phenotype; an essential requirement for modelling healthy corneal stroma. As-prepared 3D-CSM hold great promise as corneal stromal substitutes for research and translation, with the potential to be used for full-thickness cornea replacement.
构建模仿天然组织功能和解剖结构的角膜基质（或角膜基质层）对于体外建模和体内再生至关重要。然而，生物工程仿生角膜基质的实例却很少。在此，我们描述了一种使用纯电压实胶原蛋白（EC）构建的正交定向三维角膜基质模型（3D-CSM）。EC膜由排列整齐的胶原纤维组成，并支持原代人角膜基质细胞（hCSCs）。负载细胞的构建体类似于天然人角膜的解剖结构。hCSCs受EC膜排列整齐的胶原纤维提供的地形线索引导。重要的是，3D-CSM可生物降解、高度透明、具有葡萄糖渗透性且包含静止的hCSCs。基因表达分析表明，排列整齐的胶原纤维的存在与活性成纤维细胞/肌成纤维细胞标志物α-SMA和Thy-1的下调密切相关，同时休眠角膜细胞标志物ALDH3上调。3D-CSM代表了首个由纯电压实胶原蛋白构建的、用于细胞和组织支持的、具有最佳强度的仿生工程角膜基质实例。3D-CSM是合成角膜基质工程的一项重大进展，有可能用于全层和功能性角膜置换，以及为体内组织再生提供信息。重要性声明：本手稿代表了首个由纯电压实胶原蛋白构建的、坚固、透明、具有葡萄糖渗透性且基于纯胶原蛋白的仿生三维角膜基质模型（3D-CSM）实例。3D-CSM的胶原纤维排列整齐且呈正交排列，模仿天然人角膜基质。胶原纤维的排列与电压实所施加电流的方向相关，并影响人角膜基质细胞（hCSC）的取向。此外，3D-CSM构建体支持角膜角膜细胞表型；这是模拟健康角膜基质的一项基本要求。制备好的3D-CSM作为角膜基质替代物用于研究和转化具有巨大潜力，有可能用于全层角膜置换。
