MODIFICATION OF CORNEAL TISSUE ENGINEERED SCAFFOLDS TO PROMOTE EPITHELIALIZATION

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。用合成材料增加和替换角膜的尝试遇到了有限的困难，主要是因为这些装置不能支持和维持正常的复层上皮。基本问题是宿主上皮细胞将聚合物表面识别为不同于基质或“自身”，因此，在植入物的整个寿命期间存在一定程度的异物反应。虽然天然材料通常具有良好的生物相容性，但它们缺乏支持组织再生的强度和承受自然伤口重塑过程的能力。因此，考虑利用合成和天然材料的优点用于组织工程应用的组合策略是有利的。对于角膜材料构建，特别需要最少2层微结构化支架以将上皮层与基质细胞层分离。支架材料的中心部分必须支持基质细胞的浸润和生长，而支架的外表面必须允许上皮层的粘附和维持。也需要共价连接到支架表面的细胞外基质蛋白（ECMP）和肽来增强细胞生长。我们建议整合新的化学，微/纳米纤维和细胞生物学方法，首先了解，然后控制角膜上皮和基质细胞材料的相互作用，作为一种方法来设计一种有效的角膜替代/增强材料。我们的具体目标如下：具体目标I：开发和表征硅酮水凝胶、胶原蛋白和壳聚糖（和/或其共聚物）的三维支架，作为最佳角膜置换/增强材料的框架。 具体目标二：为了增加最佳的细胞反应，开发的聚合物支架材料，通过修改其表面与栓系的ECMPs和肽，使用新的微/纳米纤维技术。 具体目标三：使用原代兔上皮细胞和角膜细胞培养物以及角膜器官培养物定量和分析对开发的聚合物支架的细胞反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Attempts to augment and replace the cornea with synthetic materials have met with limited succeass, primarily because these devices have been unable to support and maintain a normal stratified epithelium. The fundamental problem is that the host epithelial cells recognize the polymer surface as other than stroma or "self" and, therefore, a degree of foreign body response is present throughout the life of the implant. Although natural materials often have good biocompatibility, they lack the strength to support tissue regeneration and the ability to withstand the natural wound remodeling process. It is advantageous, therefore, to consider combination strategies for leveraging the advantages of synthetic and natural materials for tissue engineering applications. For corneal material construction, a minimum 2-layer microstructured scaffold is specifically required to separate the epithelial layer from the stromal cell layer. The central part of the scaffold material must support infiltration and growth of stromal cells, whereas the outer surface of the scaffold must allow the adhesion and maintenance of the epithelial layer. Extracellular matrix proteins (ECMPs) and peptides covalently tethered to the scaffold surfaces are also needed to enhance cell growth. We propose to integrate novel chemistry, micro/nanofabrication, and cell biology methods to first understand and then control corneal both epithelial and stromal cell-material interactions as a method to engineer an effective corneal replacement/augmentation material. Our specific aims are as follows: Specific Aim I: To develop and characterize 3-dimensional scaffolds of silicone hydrogels, collagen, and chitosan (and/or copolymers thereof), as the framework for an optimal corneal replacement/augmentation material. Specific Aim II: To increase optimal cellular response to the developed polymer scaffold materials by modifying their surfaces with tethered ECMPs and peptides using novel micro/nanofabrication techniques. Specific Aim III: To quantify and analyze the cellular response to the developed polymer scaffolds using primary rabbit epithelial and keratocyte cell culture and corneal organ culture.