The aim of this study was to develop a synthetic alternative to the human corneal limbus for use initially as an ex vivo model in which to study corneal stem cell function within a niche environment and ultimately to develop an implantable limbus for future clinical use. Microstereolithography was used for the fabrication of polyethylene glycol diacrylate (PEGDA) based rings on a macroscopic (1.2 cm) scale containing unique microfeatures (pockets) which were then modified with fibronectin to promote cell adhesion. These rings were designed to mimic the limbal area of the eye containing structures of the approximate size and shape of the stem cell microenvironments found in the palisades of Vogt. The attachment of rabbit limbal fibroblasts and rabbit limbal epithelial cells to the PEGDA rings was increased by pretreating the microfabricated structures with biotinylated fibronectin. Cell outgrowth from fibronectin coated microfabricated structures was 50% greater than from rings without structures or fibronectin coating. The cell loaded rings were then placed on an ex vivo wounded cornea model and the outgrowth of cells to form a multilayered epithelium was observed. We suggest this is a new approach to investigating limbal stem cells niches and the first steps towards a new approach for corneal regeneration.

中文翻译：

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开发带有微型袋的微加工人造角膜缘，用于将细胞输送到角膜。

本研究的目的是开发人类角膜缘的合成替代品，最初用作离体模型，在该模型中研究小生境环境中的角膜干细胞功能，并最终开发可植入的角膜缘以供未来临床使用。微立体光刻技术用于在宏观 (1.2 cm) 尺度上制造基于聚乙二醇二丙烯酸酯 (PEGDA) 的环，该环包含独特的微观特征（口袋），然后用纤连蛋白修饰以促进细胞粘附。这些环旨在模拟眼睛的边缘区域，其中包含与 Vogt 栅栏中发现的干细胞微环境的大小和形状近似的结构。通过用生物素化纤连蛋白预处理微制造结构，增加了兔角膜缘成纤维细胞和兔角膜缘上皮细胞对 PEGDA 环的附着。来自纤连蛋白涂层微加工结构的细胞生长比没有结构或纤连蛋白涂层的环多 50%。然后将装载细胞的环置于离体受伤角膜模型上，观察细胞生长形成多层上皮。我们建议这是一种研究角膜缘干细胞生态位的新方法，也是迈向角膜再生新方法的第一步。然后将装载细胞的环置于离体受伤的角膜模型上，观察细胞生长形成多层上皮。我们建议这是一种研究角膜缘干细胞生态位的新方法，也是迈向角膜再生新方法的第一步。然后将装载细胞的环置于离体受伤的角膜模型上，观察细胞生长形成多层上皮。我们建议这是一种研究角膜缘干细胞生态位的新方法，也是迈向角膜再生新方法的第一步。