POLYMERS Vol.62 No.2
>> Chinese >> English >> Japanese >> Korean
COVER STORY
Creation of Inorganic Materials Based on Biopolymers
COVER STORY: Highlight Reviews
Fabrication and Application of Bio-Nanomaterial by Biotemplates Kenji IWAHORI, Ichiro YAMASHITA
<Abstract> There are many methods for fabrication of nanomaterials in the world. Recently, many researchers are attracted to the “bio-template method” using small protein cages to synthesize uniform nanomaterials. These small protein cages are used as templates to synthesize nanoparticles or nanowires for nanotechnology such as fabrication of nano-electronic devices. This method is an environmental friendly method, because the synthesis of nanomaterial was achieved in aqueous solutions at room temperature. There are many kinds of nanoparticles and nanowires that are synthesized by this method. I introduce here the fabrication of nanomaterials by the bio-template method and some applications using synthesized NPs and finally a prospect of bio-nanomaterials.
Keywords: Nanomaterial / Nanoparticle / Ferritin / Nano-Devise / Bio-Template
Top of the Page▲
Biomimetic Materials Synthesis and Self-Assembly for Device Fabrications: What Have We Done and Where Do We Go with This Technology Hiroshi MATSUI
<Abstract> Peptides and proteins are advantageous to develop complex and hybrid 3D assemblies and materials due to their robust assembling nature, templating capability, and molecular recognition. This review covers how the field of peptide-based material sciences/engineering started, and continues to discuss the evolution of technology from 2D to more complex 3D assemblies. Unique features include the large scale assembly of nanomaterials in precise location, periodicity, and interparticle distance, difficult to accomplish by other technologies. Applications of biomolecular assemblies can be expected in the fields of electronics, photonics, solar cells, medical devices, tissue engineering, and metamaterials.
Keywords: Bionanotechnology / Peptides / Protiens / 3D Self-Assembly / Biomaterials / Biomimetics
Top of the Page▲
Bioinspired Synthesis of Inorganic Crystals: Molecular Control of Crystal Growth Hiroaki IMAI, Yuya OAKI
<Abstract> The structural design of biominerals consisting of building blocks with the incorporation of organic polymers has attracted the interest of researchers in a broad range of chemistry disciplines. The complex and hierarchical architectures of biominerals are formed with molecular control in an aqueous solution system at ambient atmosphere. In this article, the bioinspired formation of hierarchical inorganic crystals exhibiting a wide variety of complex morphologies are reviewed. The molecular control for the inorganic crystals would be appliable as a smart technique for the fabrication of functional nanoscale materials.
Keywords: Biomineral / Molecular Control / Crystal Growth / Organic Template / Soluble Molecule / Self-Organization
Top of the Page▲
COVER STORY: Topics and Products
Nanointerface Molecules from Material-Binding Antibodies Mitsuo UMETSU, Takamitsu HATTORI, Izumi KUMAGAI
<Abstract> Antibodies, with their high affinity and specificity, are widely utilized in the field of protein engineering, medicinal chemistry, and nanotechnology applications, and our recent studies have demonstrated the recognition and binding of antibodies to the surface of inorganic material. High affinity material-binding antibody fragments are generated on the single variable domain of the heavy chain of a heavy chain camel antibody (VHH) by a combination of peptide-grafting and phage-display techniques and they can be used for one-pot functionalization of nanoparticles as interface molecules. Multivalent and bispecific antibodies which are constructed on the material-binding VHH platform by means of fusion technology functionalized inorganic nanoparticles in one pot, and these functionalized nanoparticles can be used to obtain surface plasmon resonance scattering images of cancer cells and to spontaneously link two different nanomaterials. Here, we propose the bispecific antibodies as convenient interface molecules in nano-sized world.
Keywords: Antibody / Nanoparticle / Evolution Technology / Interface Molecule / Assembly
Top of the Page▲
Technology for Bio-Silica Fabrications Inspired by Diatom Shell Formation: Development and Perspective Yusuke MATSUDA
<Abstract> Biomineralization of silicate is commonly observed in nature. Lessons from diatom silica shell (frustle) formation have indicated that, as one of the observed natures of a frustle-forming factor, Silaffin, silica forming peptides are strongly cationic. Our recent study demonstrated that basic amino acids, lysine and arginine, also mineralize silicate by themselves, although required concentrations of these free amino acids were above 5 mM while cationic peptides required for efficient silica formation were about 30 nM in the presence of 0.1 M silicate, indicating efficiency of more than two orders of magnitude higher compared to free amino acids. Amphipathic α-helix peptide was obtained from a diatom pyrenoid forming carbonic anhydrase, PtCA1, and basic amino acids were introduced to this helix by gene engineering. Resulting cationized-diatom-pyrenoid-forming factor, CDPF, revealed biosilica formation with high activity which is equivalent to that of diatom Silaffin. Our study demonstrates a high potential to create silica-based materials using peptides which are obtained from natural resources or protein engineering.
Keywords: Diatom / Biosilica / Cationic Peptide / Protamine
Top of the Page▲
Metal-Complexed Organic Nanotubes Self-Assembled from Peptide Lipids Masaki KOGISO, Masaru AOYAGI
<Abstract> Organic nanotubes (ONTs) are expected as a novel nano-container for versatile functional materials. Peptide lipids comprising of a glycyl-glycine and an alkyl chain self-assemble to form the organic nanotubes through unique polyglycine-II type hydrogen-bond networks. Metal-complexed organic nanotubes (M-ONTs) are unique ONTs made of metal-complex of the peptide lipids. When an aqueous solution of metal salt was added to a dispersion of the peptide lipids in alcohol, M-ONTs were produced immediately. We can obtain more than 100 g of dry M-ONTs using 1 L of water-alcohol mixture in a few hours. Metal ions exist both on the inner- and outer surfaces and in-between bilayer membranes. These M-ONTs are expected as novel metal or metal-organic hybrid nanomaterials through metallization using organic layers as templates. Applications as a catalyst were also investigated. Single bilayer Ni-ONT showed high catalytic activities toward the oxidation of a variety of organic molecules.
Keywords: Metal Complex / Organic Nanotube / Peptide / Self-Assembly / Catalyst
Top of the Page▲
Development of Organic/Inorganic Hybrids Based on Polymer Templates Tatsuya NISHIMURA
<Abstract> Biominerals such as bones, teeth, the nacre of seashells, and the exoskeletons of crustaceans are organic/inorganic hybrids with highly controlled hierarchical structures. We have been inspired by the structure, properties and formation processes of biominerals for the development of new functional hybrid materials. We previously reported on the formation of thin films of inorganic crystals based on this approach. The resulting hybrid materials consisting of inorganic crystals and organic polymers exhibited a wide variety of morphologies. Here we discuss our recent results for the development of new inorganic/organic hybrid materials. Unidirectionally oriented thin films and macroscopically oriented crystals have been obtained by using functional polymer templates.
Keywords: Biomineralization / Polymer Templates / Organic / Inorganic Hybrids / Recombinant Peptides / Calcium Carbonate
Top of the Page▲
Polymer Science and I: A Personal Account
Growing from “DA-RA-BU-CHI” Hiroshi ENDO
<Abstract> Was myself able to really growing from DA-RA-BU-CHI, which means a foolish person in Toyama prefecture? As for the research life through all my fortunes will be continued.
Top of the Page▲
Front-Line Polymer Science
Layer-by-Layer Assembly, Where are You Going? Katsuhiko ARIGA
<Abstract> Because layer-by-layer (LbL) assembly has especially wide versatility in materials applicability and easiness of procedure, it has been rapidly developing in both fundamental science and practical application. This assembling method resulting in sequence controlled multilayers on a nanometer-scale thickness has been applied to various nanomaterials including graphene and mesoporous materials. For example, LbL assembly of graphene nanosheets and ionic liquids provided a sensor system with superior affinities for aromatic compounds through guest accommodation within the well-defined π-electron-rich nanospace. Mesoporous silica capsules were integrated into LbL structures for development of a novel mode of drug delivery, stimuli-free automodulated delivery. Release of liquid materials from capsules in the LbL films possesses a stepwise profile even though no external stimulus was applied. Recent other research examples also show high potentials of the LbL films in biomedical applications and integration into device structures. Based on these facts, I expect a bright future for the LbL technology.
Keywords: Layer-by-Layer (LbL) Assembly / Thin Film / Nanomaterials / Graphene / Mesoporous Silica / Biomedical Application / Device
Top of the Page▲