Taki Chemical Co.

Harima, Japan

Taki Chemical Co.

Harima, Japan

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Sumiya S.,Hiroshima University | Sumiya S.,Taki Chemical Co. | Fujiwara J.,Hiroshima University | Oumi Y.,Hiroshima University | And 2 more authors.
Journal of Porous Materials | Year: 2011

Incorporation of aluminum on the inner surfaces of mesopores was carried out under hydrothermal conditions for synthesizing mesoporous silica using an anionic surfactant. The synthesis concept was based on ionic interactions between aluminum cations and anionic surfactants, with the latter as templates. We easily obtained aluminum-containing microporous silica with supermicropores. The results of pyridine adsorption and cumene cracking reactions strongly indicated that unlike the materials prepared by the previously reported post synthesis and direct synthesis methods, the larger amount of aluminum incorporated into the materials were effectively present on the inner surfaces of supermicropores. © 2010 Springer Science+Business Media, LLC.


Takao O.,Taki Chemical Co. | Imamura Y.,Taki Chemical Co. | Matsuda T.,Kanazawa Institute of Technology
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2010

Polymerization of a trimethylene carbonate (TMC) in an aqueous solution was investigated by gel permeation chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. The polymerization reaction proceeded rapidly in the aqueous solution and high conversion was achieved in a relatively short time. 1,3-Propanediol (PPD) formed by hydrolysis of TMC was used as the initiator. The TMC oligomer obtained by ring-opening polymerization had a TMC unit backbone with terminal 3-hydroxypropyl groups at both chain ends. The oligomer underwent transesterification reaction with elimination of PPD, resulting in a gradual increase in the molecular weight of the product. The molecular weight was affected by the concentration of TMC. The thermal properties of the polymers were investigated by differential scanning calorimetry. Polymers within the molecular weight (Mn) range from 6.0 × 103 to 2.3 × 104 g/mol crystallized, and endothermic peaks corresponding to the melting temperature were observed. The glass transition temperature increased with the molecular weight of the polymers. © 2010 Wiley Periodicals, Inc.


Yokoyama Y.,University of Hyogo | Yokoyama Y.,Taki Chemical Co. | Yusa S.-I.,University of Hyogo
Polymer Journal | Year: 2013

Poly(sodium styrenesulfonate)-block-poly(ethylene glycol)-block-poly(sodium styrenesulfonate) (PSS-PEG-PSS) was prepared via reversible addition-fragmentation chain transfer (RAFT) radical polymerization of sodium styrenesulfonate (SS) using a poly(ethylene glycol) (PEG)-based bifunctional macro-chain transfer agent in water. The reaction proceeded in the manner of living polymerization, suggesting that the number-average molecular weight increased linearly with monomer conversion, whereas the molecular weight distribution remained nearly constant below 1.30, independent of conversion. Poly(methacrylic acid) (PMA) homopolymer was also prepared via RAFT. When aqueous solutions of PSS-PEG-PSS and PMA were mixed below pH 5, water-soluble PSS-PEG-PSS/PMA complexes were formed as a result of hydrogen bonding interactions between the PEG block and the pendant carboxylic acids in PMA. The complex was characterized by 1H NMR spin-spin relaxation time, light scattering and transmission electron microscopy measurement techniques. The hydrodynamic radius (Rh) of the complex depended on the mixing ratio of the PSS-PEG-PSS and PMA molecules. When the mole ratio of ethylene glycol units in PSS-PEG-PSS and the pendant carboxylic acids in PMA was nearly unity, the scattering intensity and Rh exhibited maximum values for PSS-PEG-PSS and PMA, which is indicative of stoichiometric complex formation. The complex dissociated at pH greater than 5 because the hydrogen bonding interaction ceased as a result of deprotonation of the pendant carboxylic acids in PMA. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.


Oh H.H.,Japan National Institute of Advanced Industrial Science and Technology | Uemura T.,Japan National Institute of Advanced Industrial Science and Technology | Yamaguchi I.,Taki Chemical Co. | Ikoma T.,Tokyo Institute of Technology | Tanaka J.,Tokyo Institute of Technology
Journal of Bioactive and Compatible Polymers | Year: 2016

Type I collagen is an abundant component of bone tissue that has been used for bone tissue engineering using various cross-linking methods, including chemical agents, ultraviolet irradiation, and dehydrothermal treatment to enhance its physical properties. Collagens derived from mammalian animals are generally not used for implantable scaffolds owing to the potential for zoonotic infection. In addition, the toxicity of cross-linking agents and alteration of inherent properties after cross-linking have been issues. In this study, fish collagen derived from tilapia scales which are free from the risk of infection was employed to fabricate a three-dimensional porous scaffold. Tilapia scale collagen scaffolds were modified using microbial transglutaminase enzyme as a catalyst to preserve the inherent properties of collagen material. Human mesenchymal stem cells were incubated with various substitutes including tilapia scale collagen and porcine collagen-coated cell culture dishes with or without microbial transglutaminase, tilapia scale collagen, and porcine collagen scaffolds cross-linked by microbial transglutaminase. Differentiation of human mesenchymal stem cells was verified using alkaline phosphatase activity and osteocalcin assays. A remarkably enhanced expression of osteoblastic differentiation was observed selectively with tilapia scale collagen-coated dishes with/without microbial transglutaminase and tilapia scale collagen collagen scaffold cross-linked by microbial transglutaminase. Thus, the combination of tilapia scale collagen and the microbial transglutaminase cross-linking method will be useful for osteoblastic differentiation and bone tissue engineering. © 2015 SAGE Publications.


Hsu H.-H.,Japan National Institute of Advanced Industrial Science and Technology | Uemura T.,Japan National Institute of Advanced Industrial Science and Technology | Yamaguchi I.,Taki Chemical Co. | Ikoma T.,Tokyo Institute of Technology | Tanaka J.,Tokyo Institute of Technology
Journal of Bioscience and Bioengineering | Year: 2016

Fish collagen has recently been reported to be a novel biomaterial for cell and tissue culture as an alternative to conventional mammalian collagens such as bovine and porcine collagens. Fish collagen could overcome the risk of zoonosis, such as from bovine spongiform encephalopathy. Among fish collagens, tilapia collagen, the denaturing temperature of which is near 37°C, is appropriate for cell and tissue culture. In this study, we investigated chondrogenic differentiation of human mesenchymal stem cells (hMSCs) cultured on tilapia scale collagen fibrils compared with porcine collagen and non-coated dishes. The collagen fibrils were observed using a scanning electronic microscope. Safranin O staining, glycosaminoglycans (GAG) expression, and real-time PCR were examined to evaluate chondrogenesis of hMSCs on each type of collagen fibril. The results showed that hMSCs cultured on tilapia scale collagen showed stronger Safranin O staining and higher GAG expression at day 6. Results of real-time PCR indicated that hMSCs cultured on tilapia collagen showed earlier SOX9 expression on day 4 and higher AGGRECAN and COLLAGEN II expression on day 6 compared with on porcine collagen and non-coated dishes. Furthermore, low mRNA levels of bone gamma-carboxyglutamate, a specific marker of osteogenesis, showed that tilapia collagen fibrils specifically enhanced chondrogenic differentiation of hMSCs in chondrogenic medium, as well as porcine collagen. Accordingly, tilapia scale collagen may provide an appropriate collagen source for hMSC chondrogenesis in vitro. © 2016 The Society for Biotechnology, Japan.


Matsumoto R.,Japan National Institute of Advanced Industrial Science and Technology | Uemura T.,Japan National Institute of Advanced Industrial Science and Technology | Xu Z.,Tokyo Institute of Technology | Yamaguchi I.,Taki Chemical Co. | And 2 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2015

We studied the effect of fibril formation of fish scale collagen on the osteoblastic differentiation of human mesenchymal stem cells (hMSCs). We found that hMSCs adhered easily to tilapia scale collagen, which remarkably accelerated the early stage of osteoblastic differentiation in hMSCs during in vitro cell culture. Osteoblastic markers such as ALP activity, osteopontin, and bone morphogenetic protein 2 were markedly upregulated when the hMSCs were cultured on a tilapia collagen surface, especially in the early osteoblastic differentiation stage. We hypothesized that this phenomenon occurs due to specific fibril formation of tilapia collagen. Thus, we examined the time course of collagen fibril formation using high-speed atomic force microscopy. Moreover, to elucidate the effect of the orientation of fibril formation on the differentiation of hMSCs, we measured ALP activity of hMSCs cultured on two types of tilapia scale collagen membranes with different degrees of fibril formation. The ALP activity in hMSCs cultured on a fibrous collagen membrane was significantly higher than on a non-fibrous collagen membrane even before adding osteoblastic differentiation medium. These results showed that the degree of the fibril formation of tilapia collagen was essential for the osteoblastic differentiation of hMSCs. © 2014 Wiley Periodicals, Inc.


Patent
Taki Chemical Co. and TOTO Ltd. | Date: 2010-12-20

A photocatalytic coating composition comprising photocatalytic titanium oxide, silver, copper and a quaternary ammonium hydroxide. The photocatalytic coating composition may include a photocatalytic titanium oxide sol dispersed in a binder. Furthermore, a photocatalytic member includes a substrate having a surface coated with the photocatalytic coating composition. The photocatalyst coating composition can contain highly antibacterial silver by skillfully utilizing copper and a quaternary ammonium hydroxide, and accordingly can show an antibacterial effect not only in a dark place simply due to silver, but also a higher antibacterial effect in a conventional application of employing ultraviolet sterilization by concomitantly using the photocatalyst titanium oxide sol according to the present invention and an ultraviolet sterilizer.


PubMed | Japan National Institute of Advanced Industrial Science and Technology, Taki Chemical Co. and Tokyo Institute of Technology
Type: Journal Article | Journal: Journal of bioscience and bioengineering | Year: 2016

Fish collagen has recently been reported to be a novel biomaterial for cell and tissue culture as an alternative to conventional mammalian collagens such as bovine and porcine collagens. Fish collagen could overcome the risk of zoonosis, such as from bovine spongiform encephalopathy. Among fish collagens, tilapia collagen, the denaturing temperature of which is near 37C, is appropriate for cell and tissue culture. In this study, we investigated chondrogenic differentiation of human mesenchymal stem cells (hMSCs) cultured on tilapia scale collagen fibrils compared with porcine collagen and non-coated dishes. The collagen fibrils were observed using a scanning electronic microscope. Safranin O staining, glycosaminoglycans (GAG) expression, and real-time PCR were examined to evaluate chondrogenesis of hMSCs on each type of collagen fibril. The results showed that hMSCs cultured on tilapia scale collagen showed stronger Safranin O staining and higher GAG expression at day 6. Results of real-time PCR indicated that hMSCs cultured on tilapia collagen showed earlier SOX9 expression on day 4 and higher AGGRECAN and COLLAGEN II expression on day 6 compared with on porcine collagen and non-coated dishes. Furthermore, low mRNA levels of bone gamma-carboxyglutamate, a specific marker of osteogenesis, showed that tilapia collagen fibrils specifically enhanced chondrogenic differentiation of hMSCs in chondrogenic medium, as well as porcine collagen. Accordingly, tilapia scale collagen may provide an appropriate collagen source for hMSC chondrogenesis invitro.

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