Study and Application of Collagen Mimetic Peptide-Collagen Hybridization

描述（由申请人提供）：胶原蛋白是哺乳动物中最丰富的蛋白质，在组织发育和修复过程中提供结构框架，其结构和代谢异常是许多慢性疾病（例如纤维化和肿瘤生长）的共同特征。对胶原蛋白具有选择性结合亲和力的简单合成分子可以为此类疾病的诊断和治疗提供新的途径，并促进功能化胶原蛋白支架的生产，用于组织工程和药物递送中新的和改进的生物材料应用。该项目的重点是i）开发新的合成胶原模拟肽（CMP），通过独特的螺旋杂交机制特异性结合天然胶原，以及ii）创建基于胶原的组织工程支架，以空间和时间定义的方式显示形态发生信号。长期目标是开发针对疾病相关纤维化的诊断和治疗方法，并开发将细胞指导信号编码到体内胶原支架上用于组织再生和体外移植治疗的革命性方法。作为实现这些长期目标的努力的一部分，在所提出的工作中阐述了以下具体目标：1）获得CMP-胶原杂交相互作用的分子水平理解，2）开发新的CMP架构，其将允许胶原支架的精确图案化，以及3）通过采用CMP证明具有胶原结合的形态发生因子的胶原支架中的血管生成事件的空间控制。 在目标1中，CMP-胶原结合的关键假设-CMP通过形成杂合三螺旋复合物与胶原分子的未折叠结构域相互作用-通过鉴定影响结合事件的分子因素（例如CMP的螺旋倾向和胶原的未折叠水平）以及通过分离和研究CMP-胶原复合物的生物物理性质来测试。在目标2中，提出了用于胶原支架的时空修饰的新方法，其涉及可以被光触发以折叠并结合胶原的笼状-CMP的设计和合成;将在2D和3D胶原支架图案化的背景下研究光触发的结合事件。目的3试图通过使用与细胞指导性分子缀合的CMP和笼状CMP来控制胶原支架中微血管形成的空间组织（用于体内和体外系统）。 从长远来看，所提出的工作的完成将允许微血管网络的工程化，用于再血管化天然缺血组织以及血管化离体工程化组织。它还可以提供用于成像病理性瘢痕组织的新途径，以及促进用于组织工程和药物递送中的新的和改进的生物材料应用的功能化胶原支架的生产。

DESCRIPTION (provided by applicant): Collagens, the most abundant protein in mammals, provide a structural framework during tissue development and repair, and their structural and metabolic abnormalities are common to many chronic diseases (e.g. fibrosis and tumor growth). A simple synthetic molecule with selective binding affinity to collagen may offer new pathways for diagnosis and treatment of such diseases as well as facilitate production of functionalized collagen scaffolds for new and improved biomaterials applications in tissue engineering and drug delivery. This project focuses on i) developing new synthetic collagen mimetic peptides (CMPs) that bind specifically to natural collagen by a unique helix hybridization mechanism, and ii) creating collagen-based tissue engineering scaffolds that display morphogenic signals in a spatially and temporally defined manner. The long-term goals are to develop diagnostic and therapeutic methods that target disease-related fibrosis and to develop revolutionary methods for encoding cell-instructive signals onto collagen scaffolds in vivo for tissue regeneration and in vitro for transplantation therapy. As part of the efforts in achieving these long-term goals, the following specific aims are set forth in the proposed work: 1) Acquire a molecular level understanding of CMP-collagen hybridization interactions, 2) Develop new CMP architectures that will allow precise patterning of collagen scaffolds, and 3) Demonstrate spatial control of angiogenic events in collagen scaffolds with collagen- bound morphogenic factors by employment of CMPs. In aim 1, a key hypothesis for CMP-collagen binding- that CMPs interact with the unfolded domains of collagen molecules by forming a hybrid triple helical complex- is tested by identifying molecular factors that affect binding events such as CMP's helical propensity and collagen's level of unfolding, and by isolating and studying the biophysical properties of CMP-collagen complexes. In aim 2, new methods for spatio-temporal modification of collagen scaffolds are proposed that involve the design and synthesis of caged-CMPs that can be photo-triggered to fold and bind to collagen; the photo-triggered binding event will be investigated in the context of 2D and 3D collagen scaffold patterning. And aim 3 attempts to control spatial organization of microvasculature formation in collagen scaffolds (for both in vivo and in vitro systems) by employment of CMPs and caged-CMPs conjugated to cell-instructive molecules. In the long run, completion of the proposed work will allow engineering of microvasculature networks for re-vascularizing native ischemic tissues as well as vascularizing ex-vivo engineered tissues. It may also offer new pathways for imaging pathologic scar tissue as well as facilitate production of functionalized collagen scaffolds for new and improved biomaterials applications in tissue engineering and drug delivery.