新型具有拓扑结构的聚己内酯支架在促进视网膜前体细胞向感光细胞分化中的作用研究

Enhanced cellular differentiation is essential for rebuilding retinal function. Recently, increasing studies indicate that mechanical cues are important for directing cell fate. In this project, a novel polycaprolactone (PCL) scaffold with different microtopographies has been constructed. Our initial study showed that retinal progenitor cells (RPCs) cultured on these PCL scaffolds had the potential to differentiate towards photoreceptor-committed cells. This project will further investigate the role of these PCL scaffolds in promoting the differentiation of RPCs towards photoreceptors. To elucidate which one is more important between topography and stiffness/elasticity for cellular differentiation, RPCs will be cultured on different topographies of PCL scaffolds and different stiffness/elasticity of culture substrates, respectively, and the differentiation of RPCs towards photoreceptors will be compared. Combined with co-culturing RPC/PCL constructs on retinal explants, the optimal PCL scaffold for differentiation and the optimal differentiation state for transplantation will be determined. Then, transplantation of RPC/PCL constructs into the sub-retinal space will be performed to investigate the efficiency and safety of cell transplantation. The aim of this project is to provide an inexpensive and reproducible platform to differentiate cells in a controlled manner, thereby rebuilding complex and finely structured tissues of the outer retina. Moreover, exploring the interaction between cell and microenvironment will have significant implications for regenerative medicine.

要达到视网膜功能的重建，首先必须解决移植细胞的分化问题，近年来机械因素在细胞分化中的作用越来越受到关注。本课题组已合成了一种新型的具有不同拓扑结构的聚己内酯（polycaprolactone，PCL）支架，前期研究发现这些PCL支架上培养的视网膜前体细胞（retinal progenitor cells, RPCs）更易向感光细胞分化。本课题拟在此基础上进一步研究以揭示这些PCL支架的两个主要机械因素（拓扑结构和硬度/弹性）在RPCs向感光细胞分化中的作用；结合视网膜外植块的共同培养，筛选出最适合细胞分化的PCL支架和最适合细胞移植的分化阶段；进一步进行视网膜下腔移植，探索细胞移植的有效性和安全性。希望为细胞移植应用于临床提供一个价廉物美的可重复的分化平台，重建复杂而精细的视网膜。本课题从机械因素角度对细胞与微环境相互作用的初步探索对再生医学中载体的选择也具有一定的指导意义。

细胞移植可能是晚期老年黄斑变性最有希望的治疗方法之一。要达到视网膜功能的重建，首先必须解决移植细胞的分化问题，近年来机械因素在细胞分化中的作用越来越受到关注。本课题组合成了一种新型的具有不同拓扑结构的聚己内酯（polycaprolactone，PCL）支架。合成的PCL支架与常规培养载体相比具有不同的硬度/弹性。与常规培养载体相比，培养在PCL支架上的视网膜前体细胞（retinal progenitor cells, RPCs）更易向感光细胞分化，模拟感光细胞的形态，表达感光细胞的特异性标志。 合成的PCL支架可以成功移植到视网膜下腔，与单细胞移植相比，通过PCL支架移植的RPCs整合率更高，其中整合到外核层的移植细胞可以表达感光细胞的特异性标志。这些结果提示PCL支架可以作为一个价廉物美的可重复的分化平台，利用其机械特性诱导RPCs向感光细胞定型细胞分化，进一步作为细胞移植的载体，提高细胞移植的整合率和向成熟感光细胞的分化效率。这将为细胞移植应用于临床提供大量的种子细胞，结果也将对再生医学中载体的选择具有一定的指导意义。