研究者詳細 - 早川　聡

MISC - 早川　聡

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キトサン-シリケートハイブリッドの構造と細胞適合性

都留寛治, 城崎由紀, 岡山知幸, 早川聡, 尾坂明義

キチン・キトサン研究 = Chitin and chitosan research 11 ( 2 ) 112 - 113 2005年7月

Conformational change of protein due to contact with bioceramic materials

S Nagai, K Tsuru, S Hayakawa, A Osaka

BIOCERAMICS, VOL 17 284-286 517 - 520 2005年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

The structural change of bovine serum albumin (BSA) was analyzed by means of ultraviolet (UV) and circular dichroism (CD) spectroscopy due to in contact with ceramics powders such as Al2O3, SiO2, TiO2, ZrO2, hydroxyapatite and beta-tricalcium phosphate. The absorbance of the UV spectra increased for the BSA solution in contact with TiO2, ZrO2 and Al2O3, that is, the BSA solution clouded. This indicated the aggregation of BSA after contact with those ceramics powders. The CD spectroscopy showed that the ordered secondary structure of BSA was diminished on contact with TiO2 and ZrO2. We discussed the protein adsorption property of ceramics on the basis of the magnitude of the interaction forces between proteins and the bioceramics.

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Blood compatibility of organic-inorganic biomedical materials

A Osaka, T Yoshioka, T Yabuta, K Tsuru, S Hayakawa

BIOCERAMICS, VOL 17 284-286 713 - 716 2005年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

Organic-inorganic hybrids involving Ti-O bonds were coated on stainless-steel (SUS316L) substrates. Tetraisopropoxide and titanium methacrylate triisopropoxide were employed as the major starting chemicals to provide TiO2-polydimethylsiloxane (PDMS) layers or organotitanium molecular thin layers, respectively. Fourier transform infrared spectra indicated that each layer contained Ti-O bonds in their structure. The obtained hybrid layers had little effects on the blood-clotting times such as active partial thromboplastin time and prothrombin time. In addition, the number of adhered platelet on the TiO2-PDMS layers depended on the composition, while the organotitanium molecular thin layers suppressed fibrinogen adsorption compared with coating-free SUS 316L substrate.

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Deposition of bioactive titania layers under ambient conditions due to hydrolysis of titanium oxysulfate aqueous solutions

Fan Xiao, Kanji Tsuru, Satoshi Hayakawa, Akiyoshi Osaka

Archives of BioCeramics Research 2005年

In vitro apatite formation on nano-crystalline titanium oxide layer grown at glass-coating/titanium interface

Satoshi Hayakawa, Yongxing Liu, Kanji Tsuru, Akiyoshi Osaka, Eiji Fujii, Kouji Kawabata

Archives of BioCeramics Research 2005年

Nano-crystalline Titanium oxide layer grown at glass-coating/titanium interface for biomedical application,

Satoshi Hayakawa, Yongxing Liu, Kazuya Okamoto, Ayako Sekikawa, Kanji Tsuru, Akiyoshi Osaka

Proceedings of Third Balkan Conference on Glass Science and Technology, 15th Conference on Glass and Ceramics 2005年

Surface characterization and corrosion behavior of NiTi alloy coated with nano-crystalline titanium oxide film

Miho Yamamoto, Kanji Tsuru, Satoshi Hayakawa, Akiyoshi Osaka, Eiji Fujii, Kouji Kawabata

Archives of BioCeramics Research 2005年

In vitro protein release behavior of gelatin-silicate porous hybrids

Kanji Tsuru, Mitsuyuki Nagahara, Satoshi Hayakawa, Akiyoshi Osaka, Kerntaro Deguishi, Nam-ho Huh

Archives of BioCeramics Research 2005年

Preparation of titanate nano-rod array on titanium substrates by novel microflux method

YX Liu, K Okamoto, S Hayakawa, K Tsuru, A Osaka

CERAMIC NANOMATERIALS AND NANOTECHNOLOGY III 159 193 - 199 2005年

記述言語：英語出版者・発行元：AMER CERAMIC SOC

We proposed a new approach on preparing titania or titanate nano- or micro-rod arrays on metallic titanium (alpha-Ti) surfaces by coating a layer of sodium tetraborate or potassium metaborate on titanium substrates and subsequent thermal treatment. Thin-film X-ray diffraction analysis indicated that the sodium tetraborate gave rutile (TiO2: PDF# 21-1276) micro-rod array. The potassium metaborate, in contrast, yielded a potassium titanate (K2Ti6O13: PDF# 40-0403) nano-rod array. The rods in the arrays grew almost perpendicular to the substrate surface.

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In vitro biodegradability of chitosan-organosiloxane hybrid membrane

K Tsuru, Y Shirosaki, S Hayakawa, A Osaka, MA Lopes, JD Santos, MH Fernandes

BIOCERAMICS, VOL 17 284-286 823 - 826 2005年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

Chitosan-silicate hybrid membranes were prepared using gamma-glycidoxypropyltrimethoxysilane (GPSM) through a sol-gel process. The amino groups of chitosan chains were reacted with the epoxy groups of GPSM and GPSM have a function as the agent to cross-link the chitosan chains. The cross-linking degree of the hybrid membranes was determined by ninhydrin assay. Fourier-transform infrared (FT-IR) spectroscopy and Si-29 cross-polarization (CP) magic-angle spinning (MAS)-NMR spectroscopy were used to assess the structure of the hybrid membranes. The biodegradability of the hybrid membranes in phosphate-buffered saline solution or lysozyme solution was investigated as a function of the GPSM concentration.

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ガラス研究機関訪問ガラス構造のコンセプトに触発されたハイブリッド医用材料の設計と創成

都留寛治, 早川聡, 尾坂明義

ニュ-ガラス 20 ( 4 ) 57 - 62 2005年

ヒドロキシアパタイトとリン酸エステル系機能性モノマーの化学的相互作用

泓川大輔, 吉田靖弘, 鈴木一臣, 早川聡, 尾坂明義, VAN MEERBEEK B.

歯材器 24 P - 35 2005年

ナノ結晶性酸化チタン層のin vitro生体活性に及ぼす無機イオン吸着の影響

松浦直子, 都留寛治, 早川聡, 尾坂明義, 吉田靖弘, 鈴木一臣, 窪木拓男

日本セラミックス協会秋季シンポジウム講演予稿集 18th 2005年

Hydroxyapatite formation on and inside of cotton fibrilla with an oxysulfate solution

J. F. Liu, S. Hayakawa, K. Tsuru, A. Osaka

Transactions - 7th World Biomaterials Congress 977 2004年12月

The formation of hydroxyapatite on and inside of cotton fibrils with an oxysulfate solution was investigated. A titania layer consisting of rutile was observed to be deposited on cotton fibrils after treating in above solution. It was observed that bonelike apatite was successfully formed on entirety of cotton fibrils in SBF at 36.5°C within only 2d. It was found that rutile induces apatite deposition in SBF at 36.5 °C just as well as anatase.

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Protein adsorption properties of stainless-steel and titanium modified with alginic acid

T. Yoshioka, K. Tsuru, S. Hayakawa, A. Osaka

Transactions - 7th World Biomaterials Congress 1408 2004年12月

The protein adsorption on the alginic acid layers covalently immobilized on stainless-steel and titanium was examined by Fourier transform infrared spectroscopy using a reflection adsorption method (FT-IRRAS). The relationship between platelet adhesion and protein adsorption was also investigated. The contact angle measurement and FT-IRRAS spectra confirmed the successful immobilization of γ-APS and alginic acid onto stainless-steel and titanium substrates. The result shows that less protein adsorption leads to blood-compatible surface on the alginic acid-immobilization.

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In vitro cytocompatibility of osteoblastic cells cultured on chitosan-organosiloxane hybrid membrane

Y Shirosaki, K Tsuru, S Hayakawa, A Osaka, MA Lopes, JD Santos, MH Fernandes

BIOCERAMICS, VOL 16 254-2 857 - 860 2004年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

Chitosan-silicate hybrids were synthesized using gamma-glycidoxypropyltrimethoxysilane (GPSM) as the agent to cross-link the chitosan chains. Fourier-transform infrared (FT-IR) spectroscopy was used to analyze the structures of the hybrids. The swelling ability and the cytocompatibility of the hybrids were investigated as a function of the GPSM concentration. The swelling of the hybrids was suppressed by addition of GPSM. MG63 human osteoblastic cells were cultured on the hybrids. The adhesion and proliferation of the MG63 cells cultured on the chitosan-GPSM hybrid surface were improved comparing to that on chitosan membrane, regardless the GPSM concentration.

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Control of morphology of titania film with high apatite-forming ability derived from chemical treatments of titanium with hydrogen peroxide

S Kawasaki, K Tsuru, S Hayakawa, A Osaka

BIOCERAMICS, VOL 16 254-2 443 - 446 2004年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

We prepared titanium substrates with sub-micron scale pores and without sub-micron scale pores by means of chemical treatments with hydrogen peroxide and subsequent thermal treatments. Sub-micron scale pores were observed on the surface of the titanium substrate treated with 3 mass% H2O2 at 90degreesC for 1 h(H1) by scanning electron microscopy. On the other hand, the sub-micron scale pores were not observed on the substrate treated with 3mass% H2O2 at 90degreesC for 72 h(H72). The surface roughness, Ra of H1 and H72 substrates was 27 and 14 nm, respectively. Both substrates showed high in vitro apatite-forming ability in simulated body fluid (SBF of Kokubo's recipe). The apatite-forming ability of H72 substrate with low Ra value was higher than that of H1 with high Ra value.

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Platelet adhesion on titania film prepared from interaction of Ni-Ti alloy with hydrogen peroxide solution

S Hayakawa, K Tsuru, A Osaka

BIOCERAMICS, VOL 16 254-2 865 - 868 2004年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

Titania films were prepared from interaction of Ni-Ti shape memory alloy with hydrogen peroxide solution followed by heating at 400degreesC. The titania films consisted of crystalline phase of TiO2 (anatase). The in vitro platelet adhesion property of the titania films was examined. The titania films on Ni-Ti alloy substrates adhered less platelets than Ni-Ti alloy substrate without treatment. This indicates that the titania film can suppress the adhesion of platelet. The present chemical modification process with hydrogen peroxide solution is applicable to prevent the Ni-Ti shape memory alloy materials from platelet adhesion when in contact with blood.

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特集I バイオとガラス医用金属材料の生体適合性制御

早川聡, 都留寛治, 尾坂明義

ニューガラス Vol.19 [3],pp.21-27 ( 3 ) 21 - 27 2004年

Platelet adhesion on metal oxide layers

S Takemoto, T Yamamoto, K Tsuru, S Hayakawa, A Osaka

BIOCERAMICS, VOL 16 254-2 853 - 856 2004年

記述言語：英語出版者・発行元：TRANS TECH PUBLICATIONS LTD

This study was concerned with blood compatibility of titanium oxide layers on stainless steel. The titanium oxide layers were prepared through sol-gel process by dip-coating of tetraethyltitanate solution and heated at 500degreesC. The crystal phase, thickness and wettability of the oxide were characterized. The blood compatibility was evaluated in term of platelet adhesion using human platelet rich plasma. Consequently, with increase in the thickness of the titanium oxide layers, the number of platelet adhered on the stainless steel coated with titanium oxide layer decreased rapidly. When the thickness of titanium oxide layers on stainless steel grew more than 150 nm, the number of adherent platelets decreased less than 10% in comparison with that on non-coated stainless steel. The titanium oxide layers indicated to be more hydrophilic than non-coated stainless steel. In conclusion, the thicker and more hydrophilic titanium oxide layer on stainless steel appears to inhibit platelet adhesion.

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MISC - 早川 聡

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MISC - 早川　聡