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策略。具体而言，我们将创造新的材料，从葡萄糖胺和确定的机制，葡萄糖胺对软骨细胞和骨髓来源的干细胞的作用。氨基葡萄糖在软骨退变的临床治疗中具有悠久的历史。不幸的是，在体外的功效验证存在冲突，对氨基葡萄糖的作用机制了解甚少。一些研究人员假设葡萄糖胺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葡萄糖胺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，葡萄糖胺通过O-Glc-NAc蛋白修饰发挥作用，进而调节多种细胞活性以增加基质产生。我们还证明了当在葡糖胺存在下从软骨细胞和间充质干细胞（MSC）工程化软骨时，水凝胶中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葡萄糖胺对软骨生长的作用机制，并设计适当的修复策略。这个建议是假设驱动和设计驱动。我们假设葡萄糖胺进入细胞中的代谢己糖胺途径，支持O-GlcNAc介导的细胞反应以改善新软骨形成，而不是如研究人员先前假设的那样直接掺入糖胺聚糖合成中。在设计部分的建议，我们将调查软骨细胞和MSC响应葡糖胺在水凝胶组织工程系统。此外，我们将开发新的材料，从葡糖胺，使分子可以很容易地释放从生物材料支架体内交付。以下具体目标将涉及这些研究课题。具体目标1.评估葡萄糖胺在软骨组织工程中的活性1A：确定葡萄糖胺对软骨细胞和MSC形成软骨组织的影响。1B：确定负责葡萄糖胺细胞反应的特定生化途径。具体目标2。合成一种聚合葡糖胺，用于软骨工程的3D支架。.

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. .