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Tokoh, Chisuzu; Takabe, Keiji; Fujita, Minoru; Saiki, Hiroshi

doi:10.1023/a:1009211927183

Cited by 278 publications

(127 citation statements)

References 26 publications

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“…The oriented C(6) hydroxyl groups allow a close contact with the glucan chains, as they are being secreted and crystallized. Thus, in theory, this interaction is predicted to alter the self-assembly of glucan chains into the crystalline microfibril (15)(16)(17)(18)(19). In fact, alteration of the aggregation of cellulose microfibrils on NOC has been confirmed in this work (Fig.…”

Section: Concept Of the ''Molecular Track'' And Its Function In The Csupporting

confidence: 75%

“…3 B and C). Just as Tinopal binds with cellulose and alters its crystallinity (16), CMC and other polysaccharides bind with the cellulose, and they alter its integration into the ribbon (15,(17)(18)(19). NOC has the same effect, but is a solid surface that interacts with the secreted cellulose microfibrils before they become associated to form the ribbons.…”

Section: Concept Of the ''Molecular Track'' And Its Function In The Cmentioning

confidence: 99%

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Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Kondo

Nojiri

Hishikawa

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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Biodirected epitaxial nanodeposition of polymers was achieved on a template with an oriented molecular surface. Acetobacter xylinum synthesized a ribbon of cellulose I microfibrils onto a fixed, nematic ordered substrate of glucan chains with unique surface characteristics. The substrate directed the orientation of the motion due to the inverse force of the secretion during biosynthesis, and the microfibrils were aligned along the orientation of the molecular template. Using real-time video analysis, the patterns and rates of deposition were elucidated. Field emission scanning electron microscopy revealed that a strong molecular interaction allowed for the deposition of nascent biosynthesized 3.5-nm cellulose microfibrils with inter-microfibrillar spacings of 7-8 nm on the surface of the template. The cellulose was deposited parallel to the molecular orientation of the template. Directed cellulose synthesis and ordered movement of cells were observed only by using a nematic ordered substrate made from cellulose, and not from ordered crystalline cellulose substrates or ordered cellulose-related synthetic polymers such as polyvinyl alcohol. This unique relationship between directed biosynthesis and the ordered fabrication from the nano to the micro scales could lead to new methodologies for the design of functional materials with desired nanostructures. Interfacial surface structure and interaction of materials at the nanoscale have attracted much attention in the field of nanotechnology (1). Microbiological systems have been investigated as a microscale process (2); however, recent studies showing the unique interaction of biological systems with entirely synthetic molecular assemblies have prompted consideration of a new generation of approaches for controlled nanoassembly (3). We report on an interaction of a biological system with an artificially oriented molecular substrate. The preparation of such an ordered substrate recently was achieved by Kondo and coworkers (4, 5) by dissolving native cellulose and reprecipitating it in a unique manner to form a distinctive structure termed nematic ordered cellulose (NOC) (Fig. 1). This is a unique type of glucan chain association. The structure is highly ordered but not crystalline and therefore may have exclusive properties as a material product over the native form of crystalline cellulose. The unique surface of NOC can be used as a template for the construction of nanocomposites. The methods for producing NOC also have been applied to other biopolymers, e.g., chitin, xylan, their derivatives, and blends of these polymers, and these will be reported in future papers.Native biopolymer assembly has been shown to be a complex process involving two separate, but integrated, steps of polymerization and crystallization (6). In particular, cellulose has been shown to be assembled by a macromolecular complex of enzymes located on the cell surface (7). Nature has designed an efficient system for regulating the molecular weight, crystallinity, size, and shape of the nanostruct...

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Section: Concept Of the ''Molecular Track'' And Its Function In The Csupporting

confidence: 75%

Section: Concept Of the ''Molecular Track'' And Its Function In The Cmentioning

confidence: 99%

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Kondo

Nojiri

Hishikawa

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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“…[46][47][48][49] The structure of cellulose composites formed by the addition of different cellwall polysaccharides and reagents, like gluco-and galactomannans, xyloglucan, and pectin, were recently investigated using X-ray diffraction, 13 C CP/MAS NMR, and electron microscopy techniques. [50][51][52][53][54] Structural interactions between those polysaccharides have been studied, and some interesting properties of such composites were found, such as improved gel strength and stability, the alteration of both ribbon and microfibril structure, lower stiffness, and greater extensibility and strength. [50][51][52][53][54] Many studies already have shown that a pure microbial cellulose membrane can accelerate the healing process of acute and chronic skin wounds.…”

Section: Microbial Cellulose As a Wound-healing Systemmentioning

confidence: 99%

“…[50][51][52][53][54] Structural interactions between those polysaccharides have been studied, and some interesting properties of such composites were found, such as improved gel strength and stability, the alteration of both ribbon and microfibril structure, lower stiffness, and greater extensibility and strength. [50][51][52][53][54] Many studies already have shown that a pure microbial cellulose membrane can accelerate the healing process of acute and chronic skin wounds. However, these versatile MC membranes can also be infused with compounds that are known to promote healing.…”

Section: Microbial Cellulose As a Wound-healing Systemmentioning

confidence: 99%

The Future Prospects of Microbial Cellulose in Biomedical Applications

et al. 2006

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Microbial cellulose has proven to be a remarkably versatile biomaterial and can be used in wide variety of applied scientific endeavors, such as paper products, electronics, acoustics, and biomedical devices. In fact, biomedical devices recently have gained a significant amount of attention because of an increased interest in tissue-engineered products for both wound care and the regeneration of damaged or diseased organs. Due to its unique nanostructure and properties, microbial cellulose is a natural candidate for numerous medical and tissue-engineered applications. For example, a microbial cellulose membrane has been successfully used as a wound-healing device for severely damaged skin and as a small-diameter blood vessel replacement. The nonwoven ribbons of microbial cellulose microfibrils closely resemble the structure of native extracellullar matrices, suggesting that it could function as a scaffold for the production of many tissue-engineered constructs. In addition, microbial cellulose membranes, having a unique nanostructure, could have many other uses in wound healing and regenerative medicine, such as guided tissue regeneration (GTR), periodontal treatments, or as a replacement for dura mater (a membrane that surrounds brain tissue). In effect, microbial cellulose could function as a scaffold material for the regeneration of a wide variety of tissues, showing that it could eventually become an excellent platform technology for medicine. If microbial cellulose can be successfully mass produced, it will eventually become a vital biomaterial and will be used in the creation of a wide variety of medical devices and consumer products.

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“…Detection of acidic glycoconjugates in a variety of mammalian connective tissues by means of a physical development procedure into high or low iron diamine-thiocarbohydrazide-silver protein (HID or LID-TCH-SP) methods 48 . The cellulose synthesized in the mannan medium by Acetobacter xylinum in the presence of acetyl glucomannan was stained heavily by the periodic acid-thiocarbohydrazide-silver proteinate (PATAg) method for X-ray diffractometry and FT-IR spectroscopy determination of its crystal structure 49 . The presence and localization of storage polysaccharides and of polysaccharides as cell structure constituents of Paracoccidioides brasiliensis yeast-like cells and protoplasts were studied using the same technique 50 .…”

Section: Introductionmentioning

confidence: 99%

Thiocarbohydrazides: Synthesis and Reactions

Metwally¹,

Khalifa²,

Koketsu³

2012

CHEMISTRY

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Thiocarbohydrazides are an important class of compounds which possess applications in many fields. The chemistry of thiocarbohydrazides has gained increased interest in both synthetic organic chemistry and biological fields and has considerable value in many useful applications such as the assessment process of the three-dimensional ultrastructure examination techniques of interphase nuclei and tissues, besides their therapeutic importance. They are also described for use as fogging agents and are considered as safe, storable, and cool-burning pyrotechnic compounds for dissemination of smoke, chemical warfare agents. On the other hand, thiocarbohydrazides are used in performing a highly selective heavy metal ion adsorbent and as complexing agents for the solvent extraction separation methods. The present review covers the literature up to date for the synthesis, reactions and applications of such compounds.

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Untitled

Cited by 278 publications

References 26 publications

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

The Future Prospects of Microbial Cellulose in Biomedical Applications

Thiocarbohydrazides: Synthesis and Reactions

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