Glycosylated Nanoparticles to Inhibit Receptor Clustering

描述（由申请人提供）：已知受体酪氨酸激酶和其他细胞表面受体通过配体诱导的二聚体或聚类激活信号转导途径，导致一系列重要的健康相关后果，如细胞增殖、炎症反应和血管生成。受体聚集通常是由肝素结合蛋白与附近的蛋白聚糖结合而促进的。该提案将基于一种称为反聚类的新概念开发一类新的受体抑制剂，其中纳米大小的复合物将与多个受体结合，但将它们保持在阻滞状态。硫酸低聚糖配体将被接枝到胶体金纳米颗粒上，作为选择性募集和定向肝素结合信号蛋白（如生长因子或趋化因子）的多价支架。利用正交保护的低聚糖功能化纳米粒子的合成策略将被开发出来，这些低聚糖将以不同的方式被去保护和硫酸化，以产生具有不同硫酸化模式的糖基化纳米粒子（GNs）文库。具体目标包括：(1)在非脱附涂层中封装纳米颗粒并在低表面密度下用正交保护低聚糖使其功能化的可靠方法；(2)采用正交保护基团策略合成多达32种不同磺化模式的双糖；(3)磺化GN文库的生成与表征；(4)筛选GNs与成纤维细胞生长因子（FGFs）的高亲和力结合，并随后使用细胞增殖试验评估其作为FGF受体介导的信号转导抑制剂（抗聚集剂）的作用。

DESCRIPTION (provided by applicant): Receptor tyrosine kinases and other cell-surface receptors are known to activate signal transduction pathways by ligand-induced dimerization or clustering, resulting in a range of important health-related consequences such as cell proliferation, inflammatory response, and angiogenesis. Receptor clustering is often promoted by heparin-binding proteins complexed onto nearby proteoglycans. This proposal will develop a new class of receptor inhibitors based on a novel concept called anti-clustering, in which nanometer-sized complexes will bind to multiple receptors but retain them in arrested states. Sulfated oligosaccharide ligands will be grafted onto colloidal gold nanoparticles, which will serve as multivalent scaffolds for the selective recruitment and orientation of heparin-binding signaling proteins such as growth factors or chemokines. Synthetic strategies will be developed for functionalizing nanoparticles with orthogonally protected oligosaccharides, which will be deprotected and sulfated in variable order to generate libraries of glycosylated nanoparticles (GNs) with variable sulfation patterns. Specific Aims include: (1) a robust method for encapsulating nanoparticles in nondesorptive coatings and functionalizing them with orthogonally protected oligosaccharides at low surface densities; (2) orthogonal protecting-group strategies for synthesizing disaccharides with up to 32 different sulfation patterns; (3) generation and characterization of sulfated GN libraries; (4) screening of GNs for highaffinity binding to fibroblast growth factors (FGFs), and their subsequent evaluation as inhibitors (anticlustering agents) against FGF receptor-mediated signal transduction using a cell proliferation assay.