Design of supramolecular ligands that can multivalently interact with receptor proteins on cellular membranes

在这项研究中，使用多轮烷的新生物材料被设计和检验以实现与细胞膜上的受体蛋白的强结合。聚轮烷最明确的特征是环状化合物和聚合链之间的非共价键。在聚轮烷中，许多环状化合物被缠绕在带有大体积端基的线性聚合链上。通过研究，我们发现并澄清了以下问题：基于糖-聚轮烷结合物滑动运动的多价分子识别：糖是靶向的配体之一，在糖-聚轮烷结合物中，通过α-环糊精(α-CDS)沿聚乙二醇链的滑动和旋转运动，很容易在缓冲液中扩散。麦芽糖-聚轮烷偶合物具有合适的α-CDS穿线数，在水溶液中表现出较高的麦芽糖迁移率。自旋-晶格驰豫时间(T_1)和α-CDS的…表明糖基和CDS具有较高的迁移率更多的自旋-自旋弛豫时间(T_2)分析。结合物与刀豆蛋白A(ConA)的结合常数(Ka)在6次方范围内。生物医用聚乙二醇聚轮烷水凝胶(PEGPRX)是一种生物医用聚乙二醇聚轮烷可降解水凝胶的制备方法。我们设计的聚乙二醇丙交酯凝胶的水解度被聚轮烷中聚乙二醇端的酯基团的包合作用很好地控制，尽管在生理条件下处于高度膨胀的状态，但完成凝胶侵蚀的时间从几天到半年以上不等。基于生物可裂解聚轮烷的超分子特性，研究了一种由阳离子α-CD和二硫键引入的聚乙二醇链组成的链状结构的生物可裂解聚轮烷作为非病毒基因载体。聚轮烷在低电荷比下仍能形成稳定的表面带正电的聚合物。通过多轮烷的二硫键裂解和随后的α-CDS和聚乙二醇间的非共价键的超分子解离，pDNA解缩合发生。观察到DMAE-SS-PRX复合体迅速逃逸，并且DMAE-SS-PRX复合体的转染量与游离聚阳离子的量无关。这些性质在将PDNA簇递送到核更少的过程中发挥了关键作用

In this research, new biomaterials using a polyrotaxane was designed and examined to achieve strong binding with receptor proteins on cellular membranes. The most definitive feature in polyrotaxanes, in which many cyclic compounds are threaded onto linear polymeric chains capped with bulky end-groups, is the noncovalent bonds between the cyclic compounds and the polymeric chain. Through the research, we found and clarified the following matters.Multivalent Molecular Recognition Based on Sliding Motion of Saccharide-Polyrotaxane Conjugates : Saccharide, one of the ligands for targeting, in saccharide-polyrotaxane conjugates could easily diffuse in buffers via sliding and rotational motion of α-cyclodextrins (α-CDs) along a poly(ethylene glycol) (PEG) chain. A maltose-polyrotaxane conjugate with appropriate threading number of α-CDs exhibits high mobility of maltose in aqueous conditions. A high mobility of saccharide groups and α-Cds was proved by spin-lattice relaxation time (T_1) and … More spin-spin relaxation time (T_2) analysis. The association constant (K_a) between the conjugate and Concanavalin A (Con A) was in the range of 6 powers. The features of high mobility of the ligands and preserving the water clusters led to gaining a large negative enthalpy.Erosion Time-Controllable Hydrogels Using Polyrotaxanes for Cartilege Tissue Enginnering : Hydrolyzable polyrotaxanes were utilized as a cross-linker for preparing PEG-polyrotaxane hydrogels (PEG-PRX gels) for biomedical applications. The hydrolysis of our designed PEG-PRX gels was found to well controlled by inclusion complexation of ester groups located at the terminal of the PEG in the polyrotaxanes, and the time to complete hydrogel erosion varies from a few days to more than a half year in spite of their highly swollen states in physiological conditions. By using the degradation control, the PEG-PRX gels could be designed as scaffolds for cartilege cultivation.Plasmid DNA Delivery to Nucleus Based on Supramolecular Characteristics of Biocleavable Polyrotaxane : A biocleavable polyrotaxane, having a necklace-like structure consisting of many cationic α-CDs and a disulfide-introduced PEG, was examined as a non-viral gene carrier. The polyrotaxane formed a stable polyplex having positively charged surface even at low charge ratio. The pDNA decondensation occurred through disulfide cleavage of the polyrotaxane and subsequent supramolecular dissociation of the non-covalent linkages between α-CDs and PEG. Rapid endosomal escape was observed, and the transfection of the DMAE-SS-PRX polyplex is independent of the amount of free polycation. Those properties played a key role for delivery of pDNA clusters to nucleus Less