http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Seo, Jiae,Yui, Nobuhiko,Seo, Ji-Hun Elsevier 2019 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.356 No.-
<P><B>Abstract</B></P> <P>The development of a novel accelerator capable of simultaneously enhancing the cross-linking density and ductility of an epoxy resin without sacrificing the reaction rate is reported. The basic concept comprises the synthesis of a tertiary amine-functionalized polyrotaxane (PRX_NR1) accelerator: a molecular necklace structure that induces a high cross-linking density as well as active molecular movement. Fourier transform infrared spectroscopy and differential scanning calorimetry measurements confirmed that the PRX_NR1-containing epoxy resin afforded a high reaction rate. Furthermore, the cross-linking density and mechanical properties of the epoxy resin were confirmed by dynamic mechanical analysis and tensile testing. Consequently, the PRX_NR1-containing epoxy resin greatly increased the cross-linking density, thereby resulting in an increase in tensile strength and glass transition temperature. Interestingly, the epoxy resin exhibited a simultaneous increase in ductility which is important to avoid brittle fracture (low toughness) of the epoxy resins. These results indicate that the proposed molecular necklace-like supramolecular PRX_NR1 accelerator is highly effective to overcome the traditional drawbacks of an epoxy resin that pose significant problems in the industrial field.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Molecular necklace-like supramolecular accelerator for epoxy resin was suggested. </LI> <LI> The synthesized accelerator displayed fast room temperature curing rate. </LI> <LI> The cross-linking density and ductility was simultaneously enhanced. </LI> </UL> </P>
Ooya, Tooru,Kawashima, Tomokatsu,Yui, Nobuhiko The Korean Society for Biotechnology and Bioengine 2001 Biotechnology and Bioprocess Engineering Vol.6 No.4
A polyrotaxane-biotin conjugate was synthesized and its interaction with streptavidin measured using surface plasmon resonance(SPR) detection. A biodegradable polyrotaxane in which ca, 22 molecules of ${\alpha}$-cyclodextrina(${\alpha}$-CDs) were threaded onto a poly(ethylene oxide) chain(M$\sub$n:4,000) capped with benzyloxycarbonyl-L-phenylalanine was conjugated with a biotin hydorazide and 2-aminoethanol after activing the hydroxyl groups of ${\alpha}$-CDs in the polyrotaxane using N, N'-carbonyldiimidazole. The results of the high-resolution $^1$H-nyclear lmagnetic resonance($^1$H-NMR)spectra and gel permeation chromatography of the conjugate showed that ca, 11 biotin molecules were actually introduced to the polyrotaxane scaffold. An SPR analysis showed that the binding curves of the biotin molecules in the conjugate on the streptavidin-deposited surface changed in a concentration dependent manner, indicating that the biotin in the conjugate was ac-tually recognized by streptavidin. The association equilibrium constant(K$\sub$a/) of the interaction be-tween the conjugate and steptavidin tetramer was of the order 10$\^$7/. These results suggest that polyrotaxane is useful for scaffolds as a polymeric ligand in biomedical fields.
Anti-Inflammatory Response of Mannose-Conjugated Polyrotaxane Endocytosed into Macrophage
Tomo Ehashi,현훈,Nobuhiko Yui 한국고분자학회 2011 Macromolecular Research Vol.19 No.5
Macrophage response to mannose-conjugated polyrotaxane (Man-PRX) was examined in terms of the morphological changes in macrophage-like J774.1 cells and their inflammation-related cytokine expression. The results obtained were compared with those by mannose-conjugated α-CD (Man-CD), mannan, and mannose-conjugated polyacrylamide (Man-PAAm). The largest percentage of the morphological change was observed for Man-PRX, which is presumably induced by mannose receptor-mediated endocytosis. In the cytokine expression experiments,anti-inflammatory cytokine was expressed by Man-PRX but the pro-inflammatory cytokine level was increased by Man-PAAm. Therefore, Man-PRX has great potential as anti-inflammatory biomaterial.
Supramolecular Structures with Cyclodextrins for Biomedical Applications
Yoon Ki Joung,박기동,Hyung Dal Park,Nobuhiko Yui 한국생체재료학회 2007 생체재료학회지 Vol.11 No.4
Supramolecular structures by the host-guest interaction between cyclodextrins and polymers, inclusion complexes, have been investigated and developed to apply to biomedical fields. An example of the supramolecular structure is anionic polyrotaxanes with sulfonyl or carboxyl group, showing blood compatibility such as anticoagulant activity and antithrombin III binding activity as well as other biocompatible properties. Second example is supramolecular network systems with temperature- and/or pH-sensitive properties, giving biomedical hydrogels. In addition, a simple supramolecular structure was electrospun to fabricate a new nanofiber for practical uses as biomaterials. These studies demonstrated that supramolecular structures with cyclodextrins are potential candidate of ‘smart’ biomaterials with functions, such as stimuli-sensitivity or biocompatibility, in various biomedical applications.
Park Hyung Dal,Bae Jin Woo,Park Ki Dong,Ooya Tooru,Yui Nobuhiko,Jang Jun-Hyeog,Han Dong Keun,Shin Jung-Woog The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.1
Sulfonated poly(ethylene glycol) (PEG-$SO_{3}$) grafted polyrotaxanes (PRx-PEG-$SO_{3}$) were prepared in order to utilize the unique properties of PEG-$SO_{3}$ and the supramolecular structure of PRx, in which PEG-$SO_{3}$ grafted $\alpha$-cyclodextrins ($\alpha$-CDs) were threaded onto PEG segments in a PEG-b-poly(propylene glycol) (PPG)-b-PEG triblock copolymer (Pluronic) chain capped with bulky end groups. Some of the PRx-PEG-$SO_{3}$ demonstrated a higher anticoagulant activity in case of PRx-PEG-$SO_{3}$ (P 105), and compared with the control they showed a lower fibrinogen adsorption in PRx-PEG-$SO_{3}$ (F68) and a higher binding affinity with fibroblast growth factor. The obtained results suggested that polyrotaxane incorporated with PEG-$SO_{3}$ may be applicable to the surface modification of clinically used polymers, especially for blood/cell compatible medical devices.