Faculty Profiles - OHTSUKI Chikara

Papers - OHTSUKI Chikara

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RSC Advances, 14, 38660-38667 (2024). (DOI: ) Reviewed Open Access

Wanyu Dong, Yuko Matsukawa, Yanglifu Long, Yoshinao Hayashi, Jin Nakamura, Kazumasa, Suzuki and Chikara Ohtsuki

RSC Advances Vol. 14 page： 38660 - 38667 2024.12

Apatite Formation on α-Tricalcium Phosphate Modified with Bioresponsive Ceramics in Simulated Body Fluid Containing Alkaline Phosphatase Reviewed

Taishi Yokoi, Shinji Tomita, Jin Nakamura, Ayae Sugawara-Narutaki, Yuko Matsukawa, Masakazu Kawashita and Chikara Ohtsuki

Biomimetics Vol. 9 ( 8 ) page： 502 2024.8

Loading of antibiotic molecules into organically modified layered calcium silicate

Nakamura, J; Kato, H; Miyazaki, T; Ohtsuki, C

JOURNAL OF ASIAN CERAMIC SOCIETIES Vol. 12 ( 3 ) page： 227 - 233 2024.7

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

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 2023.1

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

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, Ayae Sugawara‐narutaki

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

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

Physically crosslinked hydrogels with thixotropic properties attract considerable attention in the biomedical research field because their self‐healing nature is useful in cell encapsulation, as injectable gels, and as bioinks for three‐dimensional (3D) bioprinting. Here, we report the formation of thixotropic hydrogels containing nanofibers of double‐hydrophobic elastin‐like polypeptides (ELPs). The hydrogels are obtained with the double‐hydrophobic ELPs at 0.5 wt%, the concentration of which is an order of magnitude lower than those for previously reported ELP hydrogels. Although the kinetics of hydrogel formation is slower for the double‐hydrophobic ELP with a cell-binding sequence, the storage moduli G’ of mature hydrogels are similar regardless of the presence of a cell‐binding sequence. Reversible gel–sol transitions are demonstrated in step‐strain rheological measurements. The degree of recovery of the storage modulus G’ after the removal of high shear stress is improved by chemical crosslinking of nanofibers when intermolecular crosslinking is successful. This work would provide deeper insight into the structure–property relationships of the self‐assembling polypeptides and a better design strategy for hydrogels with desired viscoelastic properties.

DOI： 10.3390/ijms22084104

Web of Science

Scopus

PubMed

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

Introduction of alkylammonium into calcium silicate hydrate towards application in development of novel biomaterial

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

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy Vol. 65 ( 6 ) page： 325 - 327 2018

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of the Japan Society of Powder and Powder Metallurgy

Human body contains trace inorganic elements that play important roles in the regulation of vital reactions. Biomaterials releasing the trace inorganic elements are suggested to be beneficial for tissue reconstruction remedies. The authors focused on inorganic layered compounds that give drug-releasing system tailored by assembling nanosheet-like crystals of the compounds with inserting ions and macromolecules which promote tissue regeneration. In the present study, calcium silicate hydrate (C-S-H) was selected as the framework, and its preparation conditions via precipitation method were explored. Moreover, the incorporation behaviors of alkylammonium molecules into the C-S-H were evaluated by their simultaneous addition during the method. Agglomerates of nanosheet-like C-S-H were precipitated by introducing calcium nitrate aqueous solution into equimolar concentration of sodium silicate aqueous solution in a controlled manner. By soaking C-S-H into simulated body fluid, which mimicked the inorganic elemental composition of human blood plasma, bone-like apatite was precipitated on its surface. The incorporation of tetrabuthylammonium cations (TBA+) were conducted by the addition of its hydroxide into sodium silicate aqueous solution during the preparation. XRD pattern of the sample showed the broadening of a peak, attributed to the interlayer distances in a C-S-H crystal. These results suggested the introduction of TBA+ in the C-S-H.

DOI： 10.2497/jjspm.65.325

Scopus

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

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Papers - OHTSUKI Chikara