Synthesis amd Mechanism of Polyglucosamine for Cartilage Tissue Engineering

描述(由申请人提供)：本研究的总体目标是设计软骨修复的策略。具体地说，我们将创造从氨基葡萄糖衍生的新材料，并确定氨基葡萄糖对软骨细胞和骨髓源干细胞的作用机制。氨基葡萄糖用于软骨退行性变的临床治疗已有很长的历史。不幸的是，对体外疗效的验证相互矛盾，对氨基葡萄糖的作用机制知之甚少。一些研究人员假设氨基葡萄糖的功能是直接增加软骨多糖的合成。糖生物学家的专业知识对于最终了解氨基葡萄糖对软骨的活性至关重要。我们的初步数据和COPI专业知识表明，氨基葡萄糖通过O-GLC-NAC蛋白修饰发挥作用，而O-GLC-NAC蛋白修饰反过来调节大量细胞活动，增加基质产生。我们还证明了在氨基葡萄糖存在的情况下，从软骨细胞和间充质干细胞(MSCs)工程软骨时，水凝胶中的软骨细胞外基质沉积增加。这项研究的结果将使我们能够明确地提供氨基葡萄糖对软骨生长的作用机制，并设计适当的修复策略。这一提议既是假设驱动的，也是设计驱动的。我们假设，氨基葡萄糖进入支持O-GlcNAc介导的细胞反应的代谢己糖途径，以促进新的软骨形成，而不是像研究人员先前假设的那样，直接并入糖胺聚糖的合成。在该提案的设计部分，我们将研究水凝胶组织工程系统中软骨细胞和MSC对氨基葡萄糖的反应。此外，我们将开发从氨基葡萄糖衍生的新材料，以便分子可以很容易地从生物材料支架中释放出来，以便在体内释放。以下具体目标将针对这些研究主题。具体目的1.评价氨基葡萄糖在软骨组织工程中的活性1A：测定氨基葡萄糖对软骨细胞和MSCs软骨组织形成的影响。1B：确定负责细胞对氨基葡萄糖反应的特定生化途径。具体目的2.合成一种可用于软骨工程三维支架的聚合物氨基葡萄糖。。

DESCRIPTION (provided by applicant): The overall goal of this researches to design strategies for cartilage repair. Specifically, we will create novel materials derived from glucosamine and determine the mechanism of glucosamine action on chondrocytes and bone marrow derived stem cells. Glucosamine has had a long history in clinical treatment of cartilage degeneration. Unfortunately there has been conflicting validation of efficacy in vitro and little understanding of glucosamine's mechanism of action. Some researchers have hypothesized that glucosamine functions to directly increase cartilage polysaccharide synthesis. The expertise of a glycobiologist is critical to finally understanding glucosamine activity on cartilage. Our preliminary data and coPI expertise demonstrates that glucosamine functions by O-Glc-NAc protein modification which in turn regulates numerous cell activities to increase matrix production. We have also demonstrated increased cartilage extracellular matrix deposition in hydrogels when engineering cartilage from chondrocytes and mesenchymal stem cells (MSCs) in the presence of glucosamine. Results of this study will allow us to definitively provide the mechanism of glucosamine action on cartilage growth and design appropriate repair strategies. This proposal is both hypothesis driven and design driven. We hypothesize that glucosamine enters the metabolic hexosamine pathway in cells that supports O-GlcNAc-mediated cell responses to improve new cartilage formation instead of being directly incorporated into glycosaminoglycan synthesis as previously hypothesized by researchers. In the design portion of the proposal we will investigate chondrocyte and MSC response to glucosamine in hydrogel tissue engineering systems. Furthermore, we will develop novel materials derived from glucosamine so that the molecule can be readily released from a biomaterial scaffold for in vivo delivery. The following specific aims will address these research topics. Specific aim 1. Evaluate glucosamine activity on cartilage tissue engineering 1A: Determine glucosamine influence on cartilage tissue formation by chondrocytes and MSCs. 1B: Identify specific biochemical pathways responsible for cellular responses to glucosamine. Specific aim 2. Synthesize a polymeric glucosamine for incorporation into 3D scaffolds for cartilage engineering. .