http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bone-like peptide/hydroxyapatite nanocomposites assembled with multi-level hierarchical structures
Ryu, Jungki,Ku, Sook Hee,Lee, Minah,Park, Chan Beum Royal Society of Chemistry 2011 SOFT MATTER Vol.7 No.16
<P>Inspired by nature's strategy for creating organic/inorganic hybrid composite materials, we developed a simple but powerful method to synthesize bone-like peptide/hydroxyapatite nanocomposites using a mussel-mimetic adhesive, polydopamine. We found that polydopamine was uniformly coated in a graphite-like layered structure on the surface of self-assembled diphenylalanine (Phe-Phe, FF) nanowires and enabled the epitaxial growth of <I>c</I>-axis-oriented hydroxyapatite nanocrystals along the nanowires, which is similar to mineralized collagen nanofibers of natural bone. The mineralized peptide nanowires were further organized in relation to each other and then readily hybridized with osteoblastic cells, resulting in the formation of multi-level hierarchical structures. They were found to be nontoxic and enabled efficient adhesion and proliferation of osteoblastic cells by guiding filopoidal extension.</P> <P>Graphic Abstract</P><P>Polydopamine-coated peptide nanowires are readily mineralized with <I>c</I>-axis-oriented carbonated hydroxyapatite nanocrystals and then hybridized with osteoblasts, forming multi-level hierarchical structures as observed in mineralized collagen of natural bone. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1sm05307h'> </P>
Ryu, Jungki,Park, Chan Beum Wiley Subscription Services, Inc., A Wiley Company 2010 Biotechnology and bioengineering Vol.105 No.2
<P>Understanding the self-assembly of peptides into ordered nanostructures is recently getting much attention since it can provide an alternative route for fabricating novel bio-inspired materials. In order to realize the potential of the peptide-based nanofabrication technology, however, more information is needed regarding the integrity or stability of peptide nanostructures under the process conditions encountered in their applications. In this study, we investigated the stability of self-assembled peptide nanowires (PNWs) and nanotubes (PNTs) against thermal, chemical, proteolytic attacks, and their conformational changes upon heat treatment. PNWs and PNTs were grown by the self-assembly of diphenylalanine (Phe–Phe), a peptide building block, on solid substrates at different chemical atmospheres and temperatures. The incubation of diphenylalanine under aniline vapor at 150°C led to the formation of PNWs, while its incubation with water vapor at 25°C produced PNTs. We analyzed the stability of peptide nanostructures using multiple tools, such as electron microscopy, thermal analysis tools, circular dichroism, and Fourier-transform infrared spectroscopy. Our results show that PNWs are highly stable up to 200°C and remain unchanged when incubated in aqueous solutions (from pH 1 to 14) or in various chemical solvents (from polar to non-polar). In contrast, PNTs started to disintegrate even at 100°C and underwent a conformational change at an elevated temperature. When we further studied their resistance to a proteolytic environment, we discovered that PNWs kept their initial structure while PNTs fully disintegrated. We found that the high stability of PNWs originates from their predominant β-sheet conformation and the conformational change of diphenylalanine nanostructures. Our study suggests that self-assembled PNWs are suitable for future nano-scale applications requiring harsh processing conditions. Biotechnol. Bioeng. 2010; 105: 221–230. © 2009 Wiley Periodicals, Inc.</P>
Ryu, Jungki,Lee, Sahng Ha,Nam, Dong Heon,Park, Chan Beum WILEY‐VCH Verlag 2011 Advanced Materials Vol.23 No.16
<P>A novel application of quantum‐dot QD sensitized TiO<SUB>2</SUB> nanotubes for artificial photosynthesis is presented by Chan Beum Park and co‐workers on p. 1883. The system is conceptually very close to natural photosynthesis; photo‐excited electrons are rapidly injected to nearby reaction centers upon light irradiation and generate reducing power, driving redox reactions for synthesis of organic compounds. This study demonstrates that more efficient artificial photosynthetic systems can be developed through rational design and engineering of photosystems. </P>
Ryu, Jungki,Lee, Sahng Ha,Nam, Dong Heon,Park, Chan Beum WILEY‐VCH Verlag 2011 Advanced Materials Vol.23 No.16
<P><B>Chiral compounds are successfully photosynthesized by coupling redox biocatalysis</B> with the photoregeneration of nicotinamide cofactors on quantum‐dot‐sensitized TiO<SUB>2</SUB> nanotubes under visible light irradiation. Nanotubular morphology and hybridization of TiO<SUB>2</SUB> with CdS enables highly efficient photoregeneration of cofactors by ensuring better diffusion of reaction species and rapid charge separation. </P>
Synthesis of Diphenylalanine/Polyaniline Core/Shell Conducting Nanowires by Peptide Self-Assembly
Ryu, Jungki,Park, Chan Beum WILEY-VCH Verlag 2009 Angewandte Chemie Vol.48 No.26
<P>Breaking the mold: Self-assembled peptide nanowires were used as a template for the synthesis of hollow polyaniline (PANI) nanotubes (see scanning electron microscopy images). The thickness and the morphology of the PANI nanostructures could be controlled readily either by varying the reaction time or by applying multiple PANI coatings. <img src='wiley_img/14337851-2009-48-26-ANIE200900668-content.gif' alt='wiley_img/14337851-2009-48-26-ANIE200900668-content'> </P> <B>Graphic Abstract</B> <P>Breaking the mold: Self-assembled peptide nanowires were used as a template for the synthesis of hollow polyaniline (PANI) nanotubes (see scanning electron microscopy images). The thickness and the morphology of the PANI nanostructures could be controlled readily either by varying the reaction time or by applying multiple PANI coatings. <img src='wiley_img/14337851-2009-48-26-ANIE200900668-content.gif' alt='wiley_img/14337851-2009-48-26-ANIE200900668-content'> </P>
Synthesis of Diphenylalanine/Cobalt Oxide Hybrid Nanowires and Their Application to Energy Storage
Ryu, Jungki,Kim, Sung-Wook,Kang, Kisuk,Park, Chan Beum American Chemical Society 2010 ACS NANO Vol.4 No.1
<P>We report the synthesis of novel diphenylalanine/cobalt(II,III) oxide (Co<SUB>3</SUB>O<SUB>4</SUB>) composite nanowires by peptide self-assembly. Peptide nanowires were prepared by treating amorphous diphenylalanine film with aniline vapor at an elevated temperature. They were hybridized with Co<SUB>3</SUB>O<SUB>4</SUB> nanocrystals through the reduction of cobalt ions in an aqueous solution using sodium borohydride (NaBH<SUB>4</SUB>) without any complex processes such as heat treatment. The formation of peptide/Co<SUB>3</SUB>O<SUB>4</SUB> composite nanowires was characterized using multiple tools, such as electron microscopies and elemental analysis, and their potential application as a negative electrode for Li-ion batteries was explored by constructing Swagelok-type cells with hybrid nanowires as a working electrode and examining their charge/discharge behavior. The present study provides a useful approach for the synthesis of functional metal oxide nanomaterials by demonstrating the feasibility of peptide/Co<SUB>3</SUB>O<SUB>4</SUB> hybrid nanowires as an energy storage material.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-1/nn901156w/production/images/medium/nn-2009-01156w_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn901156w'>ACS Electronic Supporting Info</A></P>