Faculty Profiles - UCHIDA Tetsuya

Papers - UCHIDA Tetsuya

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Fundamentals and Applications of Polymer Crystallization -From Nanofiber to Artificial Retina- Invited Reviewed

Tetsuya Uchida

Proceedings of The 17th Asian Textile Conference (ATC-17) 4 2024.12

Preparation of solution-Grown Lozenge-Shaped Poly(P-Phenylene terephthalamide) Single Crystals and Their Structural Stabilization by heat Treatment Reviewed

Yutaro Hara, Tomoyasu Takaki, Tetsuya Uchida

Proceedings of International Symposium on Fiber Science and Technology 2024 (ISF2024) 289 2024.11

Preparation of transparent Sulfated Cellulose Pulp Sheet with High O2 Gas Barrier Property Reviewed

Ayato Nishimura, Michitaka Sugino, Tetsuya Uchida

Proceedings of International Symposium on Fiber Science and Technology 2024 (ISF2024) 350 2024.11

ポリエチレンフィルム表面に光電変換色素を結合した人工網膜の実男床に向けた医工連携での取り組み Invited

内田哲也

DreamaTex 12 6 - 7 2024.8

溶液結晶化を利用したポリイミドナノファイバーの作製と熱処理効果 Reviewed

二宮良太, 熊野翔太, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 31 57 - 60 2024.7

固体高分子型燃料電池の応用に向けたイオン液体ドープ剛直高分子架橋体フィルムの作製と導電性評価 Reviewed

西岡凌平, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 31 61 - 64 2024.7

剛直高分子poly(p-phenylene benzobisoxazole)(PBO)を用いて作製した板状晶の過冷却度と熱処理安定化の表面構造への影響 Reviewed

服部陽, 木下諒大, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 31 65 - 68 2024.7

超音波照射を用いた剛直高分子ナノファイバーの精製と積層マットおよび複合体フィルムへの応用 Reviewed

三津江貴史, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 31 69 - 72 2024.7

溶液結晶化による高結晶性ポリイミドナノファイバーの作製 Reviewed

熊野翔太, 鈴木圭, 松島智士, 五島敏之, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 30 77 - 80 2023.7

剛直高分子poly(p-phenylene benzobisoxazole)板状晶の結晶化と熱処理による構造安定化 Reviewed

服部陽, 木下諒大, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 30 85 - 88 2023.7

固体高分子形燃料電池への応用に向けた剛直高分子架橋体フィルムを用いたリン酸ドープ型高分子電解質膜の作製と導電性向上 Reviewed

西岡凌平, 後藤厚保, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 30 89 - 92 2023.7

高熱伝導性剛直高分子ナノファイバーの解繊条件の検討とポリカーボネート複合体フィルムへの応用 Reviewed

三津江貴史, 内田哲也

ポリイミド・芳香族系高分子最近の進歩 30 81 - 84 2023.7

Preparation of crystalline polyimide nanofibers via solution crystallization Reviewed

Shota Kumano, Tomoyasu Takaki, Tetsuya Uchida

Polymer Journal 55 ( 6 ) 717 - 722 2023.6

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

Two crystalline polyimide nanofibers (PINFs) with different morphologies were prepared. The crystalline unit cells of the aromatic PI crystals and the crystal morphologies of the fabricated PINFs were examined. PINF-I (lengths = 305 ± 152 nm and diameters = 12 ± 2 nm) was crystallized from crystalline PI dissolved in a concentrated sulfuric acid solution. The resulting PINF-I was isolated from this solution, and it did not aggregate in water. PINF-II with diameters of 105 ± 99 nm was prepared by dispersing PINF-I in a mixed water and t-butanol (TBA) solution (water:TBA = 4:1), followed by freeze-drying. Then, the PINF-II was heated to enhance its crystallinity. X-ray diffraction and transmission electron microscopy studies of the heat-treated PINF-II revealed a PI crystalline unit cell [orthorhombic, a = 1.21 nm, b = 0.88 nm, and c = 2.23 nm (molecular chain axis direction)]. The crystal structure of the heat-treated PINF-II suggested that highly crystalline PINFs were fabricated in which the PI molecular chains were oriented along the direction of the fiber lengths.

DOI： 10.1038/s41428-023-00765-w

Scopus

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Preparation of cellulose nanocrystals coated with polymer crystals and their application in composite films Reviewed

Tetsuya Uchida, Ryohei Nishioka, Risa Yanai

Polymers for Advanced Technologies 33 ( 8 ) 2511 - 2518 2022.8

Preparation of cellulose nanocrystals coated with polymer crystals and their application in composite films Reviewed

T. Uchida, R. Nishioka, R. Yanai

Polym. Adv. Technol. 33 2511 - 2518 2022.4

Clarification of degradation mechanism on retinal prosthesis using photoelectric dyes coupled to polyethylene film by mass spectrometry Reviewed

Koichiro Yamashita, Mayu Mitsui, Toshihiko Matsuo, Tetsuya Uchida

Materials Letters 307 130978 - 130978 2022.1

Preparation of highly porous heat-resistant polybenzoxazole network films and their electrical conductivities Reviewed

Tetsuya Uchida, Yukihisa Onishi, Atsu Goto

POLYMERS FOR ADVANCED TECHNOLOGIES 33 ( 1 ) 104 - 110 2022.1

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Highly porous rigid polybenzoxazole (PBO) network films were prepared using a precursor-mediated fabrication method. The obtained PBO network films possessed high porosities of similar to 40%, as calculated from their apparent densities. In addition, the 5%-weight-loss temperatures of the films were >= 570 degrees C under nitrogen atmosphere, demonstrating an excellent thermal stability. The electrical conductivities of the obtained PBO network films and phosphoric-acid-doped PBO network films were also evaluated. In addition, PBO network films containing pyridine rings were prepared and subjected to phosphoric acid doping. The resultant films were found to exhibit the highest conductivities of the films considered in this study owing to proton conduction both between phosphate groups and between the pyridine rings. The highest conductivity was found for a film prepared from a phosphoric-acid-doped PBO network containing pyridine rings, that is, 2.09 x 10(-1) S/cm at 150 degrees C, which was higher than that of Nafion (TM). Therefore, these films can be used at higher temperatures than that of Nafion (TM).

DOI： 10.1002/pat.5494

Web of Science

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Modelling the visual response to an OUReP retinal prosthesis with photoelectric dye coupled to polyethylene film Reviewed

Koichiro Yamashita, Prathima Sundaram, Tetsuya Uchida, Toshihiko Matsuo, Willy Wong

JOURNAL OF NEURAL ENGINEERING 18 ( 4 ) 2021.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

Objective. Retinal prostheses have been developed to restore vision in blind patients suffering from diseases like retinitis pigmentosa. Approach. A new type of retinal prosthesis called the Okayama University-type retinal prosthesis (OUReP) was developed by chemically coupling photoelectric dyes to a polyethylene film surface. The prosthesis works by passively generating an electric potential when stimulated by light. However, the neurophysiological mechanism of how OUReP stimulates the degenerated retina is unknown. Main results. Here, we explore how the OUReP affects retinal tissues using a finite element model to solve for the potential inside the tissue and an active Hodgkin-Huxley model based on rat vision to predict the corresponding retinal bipolar response. Significance. We show that the OUReP is likely capable of eliciting responses in retinal bipolar cells necessary to generate vision under most ambient conditions.

DOI： 10.1088/1741-2552/abf892

Web of Science

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Development of highly durable retinal prosthesis using photoelectric dyes coupled to polyethylene film and quantitative in vitro evaluation of its durability Reviewed

Koichiro Yamashita, Tenu Tanaka, Toshihiko Matsuo, Tetsuya Uchida

BIOMEDICAL MATERIALS 16 ( 4 ) 2021.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

Retinal prostheses have been developed to restore vision in blind patients suffering from such diseases as retinitis pigmentosa. In our previous studies, we developed a retinal prosthesis called dye-coupled film by chemical coupling of photoelectric dyes, which absorb light and then generate electrical potential, with a polyethylene film surface. The dye-coupled film is nontoxic, and we recovered the vision of a monkey with macular degeneration. The amount of dye on the dye-coupled film, however, decreased to one-third after five months in the monkey's eye. The photoelectric dye consists of a cation with photoresponsivity and a bromide ion (Br-). Therefore, an anion-exchange reaction could be applied to the dye-coupled film to improve its durability. In this study, the anion-exchange reaction was conducted using bis(trifluoromethanesulfonyl)imide ion (TFSI-), which has lower nucleophilicity than Br-. First, the long-term durability was examined without using animal subjects and in a short period. Subsequently, an elemental analysis was performed to confirm the exchange between Br- and TFSI-, and chemical properties, such as photoresponsivity and durability, before and after the anion exchange, were evaluated. It was quantitatively confirmed that the long-term durability of dye-coupled films can be evaluated in an in vitro environment and in a short period of one-thirtieth by utilizing a saline solution at 60 degrees C, compared with an in vivo environment. In addition, the durability of the dye-coupled film with TFSI- was improved to 270%-320% compared with that of the dye-coupled film with Br-.

DOI： 10.1088/1748-605X/abe809

Web of Science

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Photoelectric dye, NK-5962, as a potential drug for preventing retinal neurons from apoptosis: pharmacokinetic studies based on review of the evidence Reviewed International journal

Toshihiko Matsuo, Tetsuya Uchida, Shihui Liu, Satomi Onoue, Shinsaku Nakagawa, Mayumi Ishii, Kayoko Kanamitsu

Life 11 ( 6 ) 591 2021.6

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

NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 μM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 μM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa.

DOI： 10.3390/life11060591

PubMed

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