Faculty Profiles - OHTSUKI Chikara

Papers - OHTSUKI Chikara

Division display 1 - 20 of about 357 ／ All the affair displays >>

In Situ and Ex Situ Studies of Ring-Like Assembly of Silica Nanoparticles in the Presence of Poly(propylene oxide)–Poly(ethylene oxide) Block Copolymers Reviewed

Rintaro Takahashi, Kazuki Yamamoto, Ryo Sugahara, Ryusuke Otake, Keisuke Hayashi, Jin Nakamura, Chikara Ohtsuki, Sadahito Aoshima, Ayae Sugawara-Narutaki

Langmuir 2023.8

Transformation behaviour of salts composed of calcium ions and phosphate esters with different linear alkyl chain structures in a simulated body fluid modified with alkaline phosphatase

Taishi Yokoi, Akiyoshi Mio, Jin Nakamura, Ayae Sugawara-Narutaki, Masakazu Kawashita, Chikara Ohtsuki

Science and Technology of Advanced Materials Vol. 23 ( 1 ) page： 341 - 351 2022.12

Biological properties of self-assembled nanofibers of elastin-like block polypeptides for tissue-engineered vascular grafts: platelet inhibition, endothelial cell activation and smooth muscle cell maintenance Reviewed International journal

Natsume K, Nakamura J, Sato K, Ohtsuki C, Sugawara-Narutaki A

Regen Biomater Vol. 10 ( rbac111 ) page： rbac111 2022.12

Organic modification of layered zirconium phosphate/phosphonate for controlled release of therapeutic inorganic ions

Jin Nakamura, Ryoya Ito, Ryohei Kozaki, Ayae Sugawara-Narutaki, Chikara Ohtsuki

Science and Technology of Advanced Materials Vol. 22 ( 1 ) page： 1000 - 1012 2021.12

Selective adsorption of dyes on TiO₂-modified hydroxyapatite photocatalysts morphologically controlled by solvothermal synthesis

Tomoyo Goto, Sung Hun Cho, Chikara Ohtsuki and TohruSekino

Journal of Environmental Chemical Engineering Vol. 9 ( 4 ) page： 105738 2021.8

Thixotropic Hydrogels Composed of Self-Assembled Nanofibers of Double-Hydrophobic Elastin-Like Block Polypeptides

Yusuke Sugioka, Jin Nakamura, Chikara Ohtsuki and Ayae Sugawara-Narutaki

International Journal of Molecular Science Vol. 22 ( 8 ) page： 4104 2021.4

Incorporation of tetracarboxylate ions into octacalcium phosphate for the development of next-generation biofriendly materials

Taishi Yokoi, Tomoyo Goto, Mitsuo Hara, Tohru Sekino, Takahiro Seki, Masanobu Kamitakahara, Chikara Ohtsuki, Satoshi Kitaoka, Seiji Takahashi, Masakazu Kawashita

Communications Chemistry Vol. 4 ( 1 ) page： 4 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

<title>Abstract</title>Octacalcium phosphate (OCP; Ca8(HPO4)2(PO4)4 ∙ 5H2O) is a precursor of hydroxyapatite found in human bones and teeth, and is among the inorganic substances critical for hard tissue formation and regeneration in the human body. OCP has a layered structure and can incorporate carboxylate ions into its interlayers. However, studies involving the incorporation of tetracarboxylic and multivalent (pentavalent and above) carboxylic acids into OCP have not yet been reported. In this study, we investigate the incorporation of pyromellitic acid (1,2,4,5-benzenetetracarboxylic acid), a type of tetracarboxylic acid, into OCP. We established that pyromellitate ions could be incorporated into OCP by a wet chemical method using an acetate buffer solution containing pyromellitic acid. The derived OCP showed a brilliant blue emission under UV light owing to the incorporated pyromellitate ions. Incorporation of a carboxylic acid into OCP imparted new functions, which could enable the development of novel functional materials for biomedical applications.

DOI： 10.1038/s42004-020-00443-5

Web of Science

PubMed

Other Link： http://www.nature.com/articles/s42004-020-00443-5

Preparation of layered calcium silicate organically modified with two types of functional groups for varying chemical stability

Jin Nakamura, Yuna Suzuki, Ryosuke Narukawa, Ayae Sugawara-Narutaki, Chikara Ohtsuki

Journal of Asian Ceramic Societies Vol. 9 ( 1 ) page： 90 - 100 2021.1

Behaviour of calcium phosphate ester salts in a simulated body fluid modified with alkaline phosphatase: a new concept of ceramic biomaterials Reviewed

Taishi Yokoi, Tatsuki Ujiyama, Jin Nakamura, Masakazu Kawashita, Chikara Ohtsuki

Materials Advances Vol. 1 ( 9 ) page： 3215 - 3220 2020.12

Human stem cell response to layered zirconium phosphate Reviewed

Jin Nakamura, Kanta Endo, Ayae Sugawara-Narutaki, Chikara Ohtsuki(DOI: 10.1039/d0ra04924g)

RSC Advances Vol. 10 page： 36051-36057 2020.9

Tearable and Fillable Composite Sponges Capable of Heat Generation and Drug Release in Response to Alternating Magnetic Field Reviewed

Koichiro Hayashi, Atsuto Tokuda, Jin Nakamura, Ayae Sugawara-Narutaki, Chikara Ohtsuki

Materials Vol. 13 ( 16 ) page： 3637 2020.8

Hydroxyapatite Formation from Octacalcium Phosphate and Its Related Compounds: A Discussion of the Transformation Mechanism Reviewed

Taishi Yokoi, Tomoyo Goto, Takeharu Kato, Seiji Takahashi, Jin Nakamura, Tohru Sekino, Chikara Ohtsuki, Masakazu Kawashita

Bulletin of the Chemical Society of Japan Vol. 93 ( 5 ) page： 701 - 707 2020.5

Rheology of Dispersions of High-Aspect-Ratio Nanofibers Assembled from Elastin-Like Double-Hydrophobic Polypeptides Reviewed

Ayae Sugawara-Narutaki, Sawako Yasunaga, Yusuke Sugioka, Duc H. T. Le, Issei Kitamura, Jin Nakamura, Chikara Ohtsuki

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol. 20 ( 24 ) 2019.12

Ring-Like Assembly of Silica Nanospheres in the Presence of Amphiphilic Block Copolymer: Effects of Particle Size Reviewed

Chisato Atsumi, Shintaro Araoka, Kira B. Landenberger, Arihiro Kanazawa, Jin Nakamura, Chikara Ohtsuki, Sadahito Aoshima, Ayae Sugawara-Narutaki

LANGMUIR Vol. 34 ( 26 ) page： 7751 - 7758 2018.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Block copolymer-mediated self-assembly of colloidal nanoparticles has attracted great attention for the fabrication of a wide variety of nanoparticle arrays. We have previously shown that silica nanospheres (SNSs) 15 nm in diameter assemble into ring-like nanostructures in the presence of amphiphilic block copolymers poly[(2-ethoxyethyl vinyl ether)-block-(2-methoxyethyl vinyl ether)] (EOVE-MOVE) in an aqueous phase. Here, the effects of particle size of SNSs on this polymer-mediated self-assembly are studied systematically using scanning electron microscopy to observe SNSs of seven different sizes between 13 to 42 nm. SNSs of 13, 16, 19, and 21 nm in diameter assemble into nanorings in the presence of EOVE-MOVE. In contrast, larger SNSs of 26, 34, and 42 nm aggregate heavily, form chain-like networks, and remain dispersed, respectively, instead of forming ring-like nanostructures. The assembly trend for 26-42 nm-SNSs agrees with that expected from the increased colloidal stability for larger particles. Time-course observation for the assembled morphology of 16 nm-SNSs reveals that the nanorings, once formed, assemble further into network-like structures, as if the nanorings behave as building units for higher-order assembly. This indicates that the ring-like assembly is a fast process that can proceed onto random colloidal aggregation. Detailed analysis of nanoring structures revealed that the average number of SNSs comprising one ring decreased from 5.0 to 3.1 with increasing the SNS size from 13 to 21 nm. A change in the number of ring members was also observed when the length of EOVE-MOVE varied while the size of SNSs was fixed. Dynamic light scattering measurements and atomic force microscopy confirmed the SNSs/polymer composite structures. We hypothesize that a stable composite morphology may exist that is influenced by both the size of SNSs and the polymer molecular structures.

DOI： 10.1021/acs.langmuir.8b00420

Web of Science

PubMed

Apatite coating on dendrimer-modified buckypaper and the formation of nanoapatite on MWCNTs Reviewed

Tomoyuki Tajima, Tomoaki Tanaka, Hideaki Miyake, Ill Yong Kim, Chikara Ohtsuki and Yutaka Takaguchi

Polymer Journal 2018.5

Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility

Duc H. T. Le, Yoko Tsutsui, Ayae Sugawara-Narutaki, Hiroshi Yukawa, Yoshinobu Baba, Chikara Ohtsuki

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A Vol. 105 ( 9 ) page： 2475 - 2484 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and -sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. (C) 2017 Wiley Periodicals, Inc.

DOI： 10.1002/jbm.a.36105

Web of Science

PubMed

Periodic Surface-Ring Pattern Formation for Hydroxyapatite Thin Films Formed by Biomineralization-Inspired Processes

Yulai Han, Tatsuya Nishimura, Misato Iimura, Takeshi Sakamoto, Chikara Ohtsuki, Takashi Kato

LANGMUIR Vol. 33 ( 38 ) page： 10077 - 10083 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Surface morphology is a key factor that might significantly influence the properties of biomaterials. In this study, periodic surface-ring structures have been constructed for calcium phosphate thin films via biomineralization-inspired crystallization process. The patterned octacalcium phosphate crystals have been obtained on poly(2-hydroxyethyl methacrylate) (PHEMA) matrix in the presence of poly(acrylic acid) (PAA). The patterned surface morphologies of the crystal thin films could be tuned by the amount of PAA additives. In addition, the rapid and topotactic transformation to hydroxyapatite (HAP) thin films with surface-ring structures has also been achieved. This study may provide new strategy toward the design of functional calcium phosphate-based thin-film hybrids.

DOI： 10.1021/acs.langmuir.7b02126

Web of Science

Bioactive Glass-Ceramics

Yokoi, T; Miyazaki, T; Kawashita, M; Ohtsuki, C

NANOBIOCERAMICS FOR HEALTHCARE APPLICATIONS page： 213 - 237 2017

Rapid and topotactic transformation from octacalcium phosphate to hydroxyapatite (HAP): a new approach to self-organization of free-standing thin-film HAP-based nanohybrids Reviewed

Satoshi Kajiyama, Takeshi Sakamoto, Moe Inoue, Tatsuya Nishimura, Taishi Yokoi, Chikara Ohtsuki and Takashi Kato

CrystEngComm Vol. 18 page： 8388-8395 2016.9

Fabrication of Porous α-TCP/Gellan Gum Scaffold for Bone Tissue Engineering Reviewed

Jian Wen, Ill Yong Kim, Koichi Kikuta and Chikara Ohtsuki

Journal of Nanoscience and Nanotechnology Vol. 16 page： 3077-3083 2016.3

　 PREV - NEXT 　

<OHTSUKI Chikara>

Papers - OHTSUKI Chikara