Simulation of Cell Recognition As Studied by Using Macrocyclic Sacchraide Clusters

我们构建了一个以杯形[4]间苯甲醚为基础的糖簇化合物作为宿主/载体的基因传递系统。主要成就如下。(1)糖团簇形成胶束状纳米颗粒，与磷酸盐离子发生凝集。这是由糖团簇和阴离子脱水引起的熵驱动。(2)糖簇还能与质粒dna紧密结合，形成约50 nm大小的“糖病毒”。它们能够通过内吞作用转染各种细胞以表达编码蛋白。(3)内吞作用与尺寸有关，在50 nm左右优化。具有末端半乳糖残基的糖病毒会进一步聚集以降低转染活性。另一方面，它们能够通过受体介导的特异性途径靶向肝细胞。然而，由于规模因素，总体活动保持在较低水平。(4)半乳糖部分功能化的糖病毒不聚集，在体外和体内（小鼠）对肝细胞具有高亲和力和选择性。(5)因此，我们成功地构建了一个高度靶向肝细胞的基因传递系统，该系统使用具有半乳糖功能化操纵模式的非聚集半乳糖病毒。(6)鉴于蛋白聚糖在细胞外基质中的显著作用，我们还制备了硫酸软膏功能化的大环簇。它们对纤维连接蛋白-整合素介导的细胞粘附表现出显著的抑制作用，可能是由于蛋白质复合物在聚集过程中的稳定

We constructed a gene delivery system using a calix[4]resorcarene-based glycocluster compounds as hosts/carriers. The major achievements are as follows.(1) Glycoclusters form micelle-like nanoparticles, which are agglutinated with phosphate ions. This is entropy-driven via dehydration of glycoclusters and anions.(2) Glycolcusters also strongly bind to plasmid DNAs to give "glycoviruses" having a size of ca. 50 nm. They are capable of transfection of various cells via endocytosis to express encoded proteins.(3) Endocytosis is size-dependent and is optimized at around 50 nm. Glycoviruses having terminal galactose residues undergo further aggregation to lower the transfection activities. On the other hand, they are capable of targeting the hepatic cells via receptor-mediated specific pathway. The overall activity, however, is kept low due to the size factor.(4) The partially galactose-functionalized glyovirus is free from aggregation and show a high affinity as well selectivity to the hepatic cells both in vitro and in vivo (mouse).(5) We are thus successful in constructing a highly hepatocyte-targeting gene delivery system using a non-aggregating galactose-virus having a manipulated mode of galactose functionalization.(6) In view of the remarkable roles of proteoglycans in the extracellular matrices, we also prepared condroitin-sulfate functionalized macrocyclic clusters. They show a remarkably potent inhibition effect toward fibronectin-integrin mediated cell adhesion, probably as a result of stabilization of protein complexes from undergoing aggregation