Synthesis amd Mechanism of Polyglucosamine for Cartilage Tissue Engineering

描述（申请人提供）：本研究的总体目标是设计软骨修复策略。具体来说，我们将创造从葡萄糖胺衍生的新材料，并确定葡萄糖胺对软骨细胞和骨髓干细胞的作用机制。氨基葡萄糖在临床治疗软骨变性方面有着悠久的历史。不幸的是，在体外对其有效性的验证和对氨基葡萄糖作用机制的了解很少。一些研究者假设葡萄糖胺的作用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理解软骨上的葡萄糖胺活性至关重要。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，从而调节许多细胞活性以增加基质的产生。我们还证明，在葡萄糖胺存在的情况下，从软骨细胞和间充质干细胞（MSCs）中提取软骨时，水凝胶中的软骨细胞外基质沉积增加。本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。这个提议既是假设驱动的也是设计驱动的。我们假设，葡萄糖胺进入细胞的代谢己糖胺途径，支持o - glcnac介导的细胞反应，以改善新软骨的形成，而不是像之前研究人员假设的那样直接纳入糖胺聚糖合成。在提案的设计部分，我们将研究水凝胶组织工程系统中软骨细胞和间充质干细胞对氨基葡萄糖的反应。此外，我们将开发从葡萄糖胺衍生的新型材料，使分子可以很容易地从生物材料支架中释放出来，用于体内递送。以下的具体目标将解决这些研究课题。具体目标1。评估氨基葡萄糖在软骨组织工程中的活性1A：确定氨基葡萄糖对软骨细胞和间充质干细胞形成软骨组织的影响。1B：确定细胞对葡萄糖胺反应的特定生化途径。具体目标2。合成用于软骨工程三维支架的聚合氨基葡萄糖。

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. .