Faculty Profiles - HAYAKAWA Satoshi

MISC - HAYAKAWA Satoshi

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異分野融合のためのバイオマテリアルの基礎PART3 分析：セラミックバイオマテリアルのキャラクタリゼーション

早川聡, 都留寛治, 尾坂明義

バイオマテリアル－生体材料 25 ( 6 ) 383 - 392 2007

HYDROXYAPATITE HYBRIDIZED WITH METAL OXIDES FOR BIOMEDICAL APPLICATIONS

Akiyoshi Osaka, Eiji Fujii, Koji Kawabata, Hideyuki Yoshimatsu, Satoshi Hayakawa, Kanji Tsuru, Christian Bonhomme, Florence Babonneau

ADVANCES IN BIOCERAMICS AND BIOCOMPOSITES II 27 ( 6 ) 39 - + 2007

Language：English Publisher：AMER CERAMIC SOC

Zn-substituted apatites with homogeneous Zn distribution in the particles (Zn center dot HAp) and those with graded distribution (Zn/HAp) were prepared via a conventional wet chemical synthesis and soaking the Zn-free apatite particles in zinc nitrate solutions X-ray photoelectron spectra of the apatites confirmed such Zn distribution Physical and chemical properties such as particle size, specific surface area, or zeta-potential and were correlated to adsorption of beta(2)-microglobulin (beta(2)-MG) and bovine serum albumin (BSA) Adsorption of beta(2)-MG on both apatites increased with the Zn content, whereas more beta(2)-MG was adsorbed on Zn/HAp than on Zn center dot HAp The amount of BSA adsorbed on Zn center dot HAp reached a maximum at about 1 5%, while it remained constant for Zn/HAp From the results It was suggested that Zn-substituted sites had better affinity against beta(2)-MG and favored beta(2)-MG adsorption Surface charge on the particles was one of the factors to explain the suppressed adsorption of BSA by both apatites

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In vitro apatite-forming ability of titania fims depends on their substrates

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

BIOCERAMICS, VOL 19, PTS 1 AND 2 330-332 633 - + 2007

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Titania films were coated by means of sol-gel method on various substrates such as titanium, titanium alloy, silicon wafer, stain less-stee 1, alumina, and glass slide where they coded as C5Ti, C5Ti6Al4V, C5Si, C5SUS, C5Al(2)O(3) and C5GS, respectively. Their in vilro apatite-forming ability was examined with the Kokubo's simulated body fluid (SBF; pH 7.4, 36.5 degrees C). C5Ti, C5Ti6Al4V and C5Si deposited apatite particles on their surface within 7 days, whereas, C5SUS, C5Al(2)O(3) and C5GS did not. These results implied that the in vitro apatite-forming ability of the titania films indirectly depended on the chemical or physical properties of the Substrates.

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Bonelike apatite formation on synthetic organic polymers and fiber coated with titania

Jin-Fang Liu, Satoshi Hayakawa, Kanji Tsuru, J. Z. Jiang, Akiyoshi Osaka

BIOCERAMICS, VOL 19, PTS 1 AND 2 330-332 679 - + 2007

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Rutile films were deposited on polyethylene terephatalate (PET), polytetrafluoroethylene (PTFE), Silicone, poly6-caprolactam (Nylon6), polyhexamethylene adipamide (Nylon6,6) and Nylon fiber substrates using 0.03 M TiOSO4 and 0.03 M H2O2 aqueous solution at 80 degrees C for 24 h. The rutile films exhibited excellent in vitro bioactivity as they induced apatite deposition in a simulated body fluid (SBF).

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Cell proliferation on Titania layer with in vitro apatite forming ability

S. Yabe, K. Tsuru, S. Hayakawa, A. Osaka, Y. Yoshida, K. Suzuki, T. Kuboki

BIOCERAMICS, VOL 19, PTS 1 AND 2 330-332 131 - + 2007

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Titania layer was fabricated on the titanium substrates with chemical treatment with 20ml or 40ml of hydrogen peroxide solution and subsequent heat treatment at 400 degrees C, coded as CHT20 and CHT40, respectively. CHT20 spontaneously deposited apatite on the surface in a simulated body fluid (SBF), while CHT40 did not. TF-XRD patterns showed that the diffraction intensity of anatase of CHT20 was higher than that of CHT40. It was suggested that the thicker titania layer indicated in vitro apatite forming ability. The cell proliferation of CHT20 and CHT40 were lower than NT and HT. Since the surface of titania layers became hydrophobic after autoclaving, we can suppose that the cell proliferation on CHT20 and CHT40 were lower than NT and HT due to their surface hydrophobicity.

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Preparation of hydroxyapatite/titania double layer coating on poly-l-lactide due to hydrolysis of titanium tetrachloride

Jin-Fang Liu, Satoshi Hayakawa, Kanji Tsuru, Jian-zhong Jiang, Akiyoshi Osaka

BIOCERAMICS, VOL 19, PTS 1 AND 2 330-332 687 - + 2007

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Rutile films were deposited on poly-l-lactide (PLLA) substrates using 0.5 M titanium tetrachloride aqueous solution at 40 degrees C for 72 h. The rutile films exhibited excellent in vitro bioactivity as they induced apatite deposition in a simulated body fluid (SBF) within 3 days, This simple treatment provided an effective route to synthesize bioactive and biodegradable scaffolds.

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生命機能と材料－生命機能マテリアル／生命現象マテリアル生体セラミックスの骨組織結合性発現機序とこれに基づく医用材料設計

尾坂明義, 早川聡, 都留寛治

マテリアルインテグレーション 20 ( 11 ) 2 - 7 2007

Microstructure and biomolecule adsorption property of hydroxyapatite modified with biologically active inorganic ions

Materials integration 20 ( 11 ) 78 - 83 2007

Preparation of porous organically-modified silicate hybrids cell culture matrix

K. Tsuru, S. Hayakawa, Y. Shirosaki, T. Okayama, K. Kataoka, N-H. Huh, A. Osaka

BIOCERAMICS, VOL 19, PTS 1 AND 2 330-332 1177 - + 2007

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Porous & rubbery organic-inorganic hybrids were synthesized from tetraethoxysilane (TEOS) and polydimethylsiloxane(PDMS) through a sol-gel route using sieved sucruse granules as a porogen. The porous hybrids with a high content of PDMS behaved like polymer sponge. The porosity was over 90% irrespective of the hybrid composition and the pore diameter ranged from 100 to 500 mu m. In the three-dimensional cell culture, mammalien cells were well cultured in the porous hybrids. The present results indicate that the hybrids may be a promising scaffold for developing such functional culture methods.

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異分野融合のためのバイオマテリアルの基礎PART3 導入：セラミックバイオマテリアルの特色

尾坂明義, 早川聡, 都留寛治

バイオマテリアル－生体材料 25 ( 6 ) 366 - 373 2007

Direct deposition of a rutile layer on polymer substrates to induce bioactivity in vitro

JM Wu, M Wang, S Hayakawa, K Tsuru, A Osaka

BIOCERAMICS 18, PTS 1 AND 2 309-311 419 - 422 2006

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Rutile films were deposited on polytetrafluoroethylene (PTFE) substrates using 1.5 M titanium tetrachloride aqueous solution at 60 degrees C. The rutile films exhibited excellent in vitro bioactivity as they induced apatite deposition in a simulated body fluid (SBF) within 2 days. Chlorine incorporated in the rutile films did not inhibit apatite deposition.

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Characterization of sol-gel derived titania films on titanium and biomimetic apatite-formation

T Shozui, K Tsuru, S Hayakawa, A Osaka

BIOCERAMICS 18, PTS 1 AND 2 309-311 717 - 720 2006

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Titania films with various thickness (about 100 nm to 300 nm) were prepared on titanium substrate by means of sol- gel method. Their surface energy was derived and in vitro apatite-forming ability was studied. The thickness of titania films of the sample coded C1, C3 and C5 was 98 nm, 204 nm, and 302 nm, respectively. Titania films of C5 showed smoother and more hydrophilic. The surface free energy of C5 was the highest of all. In vitro apatite-forming ability showed the titania films of C5,only. It was thus suggested that the titania films with more hydrophilic and higher surface free energy favored apatite-formation than those with smaller surface free energy.

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Selective protein adsorption property and structure of nano-crystalline hydroxy-carbonate apatite

S Hayakawa, K Ohnishi, K Tsuru, A Osaka, E Fujii, K Kawabata, F Babonneau, C Bonhomme

BIOCERAMICS 18, PTS 1 AND 2 309-311 503 - 506 2006

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

The selective protein adsorption property and the local structure around carbonate ions of nanocrystalline hydroxy-carbonate apatite were examined in this study. Considerable change in the selectivity in the adsorption of BSA and beta(2)-MG was observed due to the incorporation of the carbonate ions in hydroxyapatite lattice. Since the protein adsorption property seems to be related to the surface charge density of hydroxyapatite due to the carbonation, the chemical states of the incorporated carbonate ions were examined by the C-31 CP-MAS NMR spectroscopy. At least four peaks assignable to carbonate ions in A-site(OH-) and B-site(PO43-) were observed in C-13 CP-MAS NMR spectrum. Thus, we must take into consideration that the surface charge distribution and the decrement of polar groups such as OH- groups due to the distribution of carbonate ions in both A- and B-sites of the hydroxyapatite lattice are particularly favorable for beta(2)-MG adsorption rather than for BSA adsorption.

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In vitro bioactivity of hydrogen peroxide modified titanium: Effects of surface morphology and film thickness

JM Wu, M Wang, S Hayakawa, K Tsuru, A Osaka

BIOCERAMICS 18, PTS 1 AND 2 309-311 407 - 410 2006

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

Anatase films with various morphologies were formed on Ti surface through different approaches using hydrogen peroxide solutions. A porous anatase surface was found to favor apatite deposition in SBF, or in vitro bioactivity. Thicker films with wider crack gaps also showed enhanced in vitro bioactivity. However, the most predominant effect was the abundance of Ti-OH functional groups incorporated in the anatase films.

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31P MAS-NMR studies of CaO-P2O5 glass ceramics

AG Dias, MA Lopes, K Tsuru, S Hayakawa, JD Santos, A Osaka

BIOCERAMICS 18, PTS 1 AND 2 309-311 301 - 304 2006

Language：English Publisher：TRANS TECH PUBLICATIONS LTD

This work reports the structure of two glass ceramics prepared in the calcium phosphate system, MK5B and MT13B, using (31)p MAS-NMR technique. The results obtained showed that the network of MK5B consisted mainly of Q(1) and Q(2) groups. Besides these two groups, MT13B material also present Q(3) units. The Q(n) groups detected in both glass ceramics seem to be correlated to the crystalline phases present in their microstructure.

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SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NANOAPATITE CERAMICS POWDERS

K. Ando, S. Hayakawa, K. Tsuru, A. Osaka, E. Fujii, K. Kawabata, C. Bonhomme, F. Babonneau

Proceedings of The Sixth Asian BioCeramics Symposium 2006 2006

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ORGANIC-INORGANIC HYBRIDS PREPARED FROM HEMA AND MPS

T. Uchino, C. Ohtsuki, K. Kikuta, M. Kamitakahara, M. Tanihara, S. Hayakawa, A. Osaka

Proceedings of The Sixth Asian BioCeramics Symposium 2006 2006

IN VITRO APATITE DEPOSITION ON MICRO-PATTERNED TITANIA LAYERS

A. Kaeriyama, K. Tsuru, S. Hayakawa, A. Osaka

Proceedings of The Sixth Asian BioCeramics Symposium 2006 2006