研究者詳細 - 藤原　正澄

論文 - 藤原　正澄

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Bright Quantum-Grade Fluorescent Nanodiamonds

Keisuke Oshimi, Hitoshi Ishiwata, Hiromu Nakashima, Sara Mandić, Hina Kobayashi, Minori Teramoto, Hirokazu Tsuji, Yoshiki Nishibayashi, Yutaka Shikano, Toshu An, Masazumi Fujiwara

ACS Nano 2024年12月

Size, polyglycerol grafting, and net surface charge of iron oxide nanoparticles determine their interaction and toxicity in Caenorhabditis elegans. 査読国際誌

Yajuan Zou, Yutaka Shikano, Yuta Nishina, Naoki Komatsu, Eriko Kage-Nakadai, Masazumi Fujiwara

Chemosphere 142060 - 142060 2024年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

The widespread application of engineered nanoparticles (NPs) in environmental remediation has raised public concerns about their toxicity to aquatic organisms. Although appropriate surface modification can mitigate the ecotoxicity of NPs, the lack of polymer coating to inhibit toxicity completely and the insufficient knowledge about charge effect hinder the development of safe nanomaterials. Herein, we explored the potential of polyglycerol (PG) functionalization in alleviating the environmental risks of NPs. Iron oxide NPs (ION) of 20, 100, and 200 nm sizes (IONS, IONM and IONL, respectively) were grafted with PG to afford ION-PG. We examined the interaction of ION and ION-PG with Caenorhabditis elegans (C. elegans) and found that PG suppressed non-specific interaction of ION with C. elegans to reduce their accumulation and to inhibit their translocation. Particularly, IONS-PG was completely excluded from worms of all developmental stages. By covalently introducing sulfate, carboxyl and amino groups onto IONS-PG, we further demonstrated that positively charged IONS-PG-NH3+ induced high intestinal accumulation, cuticle adhesion and distal translocation, whereas the negatively charged IONS-PG-OSO3- and IONS-PG-COO- were excreted out. Consequently, no apparent deleterious effects on brood size and life span were observed in worms treated by IONS-PG and IONS-PG bearing negatively charged groups. This study presents new surface functionalization approaches for developing ecofriendly nanomaterials.

DOI： 10.1016/j.chemosphere.2024.142060

PubMed

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Diamond quantum sensors in microfluidics technology 査読

17 ( 5 ) 2023年9月

Glass-patternable notch-shaped microwave architecture for on-chip spin detection in biological samples. 査読国際誌

Keisuke Oshimi, Yushi Nishimura, Tsutomu Matsubara, Masuaki Tanaka, Eiji Shikoh, Li Zhao, Yajuan Zou, Naoki Komatsu, Yuta Ikado, Yuka Takezawa, Eriko Kage-Nakadai, Yumi Izutsu, Katsutoshi Yoshizato, Saho Morita, Masato Tokunaga, Hiroshi Yukawa, Yoshinobu Baba, Yoshio Teki, Masazumi Fujiwara

Lab on a chip 22 ( 13 ) 2519 - 2530 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

We report a notch-shaped coplanar microwave waveguide antenna on a glass plate designed for on-chip detection of optically detected magnetic resonance (ODMR) of fluorescent nanodiamonds (NDs). A lithographically patterned thin wire at the center of the notch area in the coplanar waveguide realizes a millimeter-scale ODMR detection area (1.5 × 2.0 mm2) and gigahertz-broadband characteristics with low reflection (∼8%). The ODMR signal intensity in the detection area is quantitatively predictable by numerical simulation. Using this chip device, we demonstrate a uniform ODMR signal intensity over the detection area for cells, tissue, and worms. The present demonstration of a chip-based microwave architecture will enable scalable chip integration of ODMR-based quantum sensing technology into various bioassay platforms.

DOI： 10.1039/d2lc00112h

PubMed

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Probing the Role of Charged Functional Groups on Nanoparticles Grafted with Polyglycerol in Protein Adsorption and Cellular Uptake 査読

Yajuan Zou, Shinji Ito, Masazumi Fujiwara, Naoki Komatsu

ADVANCED FUNCTIONAL MATERIALS 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

In biofluids, charged functional groups on the surface of nanoparticles (NPs) interact with cells through the protein corona. However, the cascade effects of charged groups on corona formation and cellular uptake remain unclear. Herein, carboxy, sulfate, and amino groups are quantitatively introduced at the periphery of polyglycerol (PG)-grafted nanodiamond and superparamagnetic iron oxide NP to probe their roles in corona formation and cellular uptake. The uptake efficiency and intracellular aggregation state of NPs are revealed to correlate with protein affinity of the charged groups; sulfate at lower density and carboxylate exhibit no affinity to proteins, inducing negligible or no cellular uptake. In contrast, sulfate at higher density and ammonium associate with fetal bovine serum proteins to alter the aggregation state of the internalized NPs. It is further demonstrated that the distinct protein corona profiles on NP-PG-OSO3- and NP-PG-NH3+ surfaces dictate their uptake mechanism. The protein corona of NP-PG-OSO3- suppresses cellular uptake via downregulation of macropinocytosis and clathrin-mediated endocytosis, whereas that of NP-PG-NH3+ enhances uptake through upregulation of macropinocytosis and caveolae-mediated endocytosis. This study clarifies the elusive role of the charged groups in protein adsorption and cellular uptake, which sheds light on NP design for controlled cellular uptake and theranostics in nanomedicine.

DOI： 10.1002/adfm.202111077

Web of Science

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π-Topology and ultrafast excited-state dynamics of remarkably photochemically stabilized pentacene derivatives with radical substituents 査読

Nishiki Minami, Kohei Yoshida, Keijiro Maeguchi, Ken Kato, Akihiro Shimizu, Genta Kashima, Masazumi Fujiwara, Chiasa Uragami, Hideki Hashimoto, Yoshio Teki

Physical Chemistry Chemical Physics 24 ( 22 ) 13514 - 13518 2022年

掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry (RSC)

π-Topologically different pentacene derivatives (1m and 1p) exhibited remarkable photochemical stability owing to the ultrafast ICS induced by a π-radical substituent. The relationship between the π-topology and the photostability is discussed.

DOI： 10.1039/d2cp00683a

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Diamond quantum thermometry: from foundations to applications 招待査読

Nanotechnology 32 ( 48 ) 482002 - 482002 2021年11月

Wide-field fluorescent nanodiamond spin measurements toward real-time large-area intracellular thermometry. 国際誌

Yushi Nishimura, Keisuke Oshimi, Yumi Umehara, Yuka Kumon, Kazu Miyaji, Hiroshi Yukawa, Yutaka Shikano, Tsutomu Matsubara, Masazumi Fujiwara, Yoshinobu Baba, Yoshio Teki

Scientific reports 11 ( 1 ) 4248 - 4248 2021年2月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Measuring optically detected magnetic resonance (ODMR) of diamond nitrogen vacancy centers significantly depends on the photon detectors used. We study camera-based wide-field ODMR measurements to examine the performance in thermometry by comparing the results to those of the confocal-based ODMR detection. We show that the temperature sensitivity of the camera-based measurements can be as high as that of the confocal detection and that possible artifacts of the ODMR shift are produced owing to the complexity of the camera-based measurements. Although measurements from wide-field ODMR of nanodiamonds in living cells can provide temperature precisions consistent with those of confocal detection, the technique requires the integration of rapid ODMR measurement protocols for better precisions. Our results can aid the development of camera-based real-time large-area spin-based thermometry of living cells.

DOI： 10.1038/s41598-021-83285-y

PubMed

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Real-time estimation of the optically detected magnetic resonance shift in diamond quantum thermometry toward biological applications 査読

Fujiwara Masazumi, Dohms Alexander, Suto Ken, Nishimura Yushi, Oshimi Keisuke, Teki Yoshio, Cai Kai, Benson Oliver, Shikano Yutaka

PHYSICAL REVIEW RESEARCH 2 ( 4 ) 043415 2020年12月

Real-time nanodiamond thermometry probing in vivo thermogenic responses 査読国際誌

Fujiwara Masazumi, Sun Simo, Dohms Alexander, Nishimura Yushi, Suto Ken, Takezawa Yuka, Oshimi Keisuke, Zhao Li, Sadzak Nikola, Umehara Yumi, Teki Yoshio, Komatsu Naoki, Benson Oliver, Shikano Yutaka, Kage-Nakadai Eriko

SCIENCE ADVANCES 6 ( 37 ) eaba9636 2020年9月

Photoprotective mechanisms in the core LH1 antenna pigment-protein complex from the purple photosynthetic bacterium, Rhodospirillum rubrum 査読

Uragami Chiasa, Sato Hiroki, Yukihira Nao, Fujiwara Masazumi, Kosumi Daisuke, Gardiner Alastair T, Cogdell Richard J, Hashimoto Hideki

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 400 112628 2020年9月

蛍光ナノダイヤモンドによる幹細胞再生機能温度センシング

宮地冬, 小林香央里, 西村勇姿, 藤原正澄, 湯川博, 馬場嘉信

Organ Biology 27 ( 2 ) 185 - 190 2020年7月

記述言語：日本語出版者・発行元：(一社)日本臓器保存生物医学会

細胞内温度が幹細胞機能に及ぼす影響について解説した。温度は生体分子のダイナミクスと反応性を通じて細胞活動を変化させる可能性が指摘されており、細胞内環境の非常に重要なパラメーターとして知られている。蛍光ナノダイヤモンド(FNDs)を用いた長期間測定可能な細胞内温度測定センシング技術を用いることにより、250μg/mL濃度以下のFNDsで標識された脂肪組織由来幹細胞(ASCs)は細胞毒性を示さないことが明らかになり、ASCsの再生機能(再生因子産生能、多分可能)に対してもFNDs標識による影響がないことが示された。細胞内温度技術は細胞・臓器保存や臓器移植技術の発展に寄与できる可能性が高いと思われる。

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Operando time-resolved diffuse reflection spectroscopy: The origins of photocatalytic water-oxidation activity of bismuth vanadate

Ryo Miyasato, Masazumi Fujiwara, Chiasa Uragami, Haruyuki Sato, Toshihiro Yano, Hideki Hashimoto

Journal of Photochemistry and Photobiology A: Chemistry 395 2020年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier B.V.

Photocatalytic water splitting has been believed to be a key technology for the construction of a sustainable society based on a renewable energy source. Understanding the exact mechanisms of oxygen evolution by water-splitting reaction, which has been regarded as a bottleneck to realize the water splitting in practical basis, should help us to enhance solar-to-hydrogen energy conversion efficiency. Here, we present a detailed investigation based on two types of bismuth vanadate (BiVO4) crystals. One is a monoclinic scheelite crystal that forms a truncated tetragonal bipyramidal shape (MS), and the other is a tetragonal zircon crystal that forms an octahedral shape (TZ). MS, which has relatively higher photocatalytic activity of water oxidation, rarely adsorbed reduced mediator (Fe2+). Operando time-resolved diffuse reflection spectral measurement demonstrated, for the first time, that the surface holes of MS crystals show extremely high reactivity, while those of TZ crystals show poor reactivity. Our investigation would promote an essential understanding of the photocatalytic reaction mechanism of water oxidation.

DOI： 10.1016/j.jphotochem.2020.112493

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A quantum thermometric sensing and analysis system using fluorescent nanodiamonds for the evaluation of living stem cell functions according to intracellular temperature 査読

Yukawa Hiroshi, Fujiwara Masazumi, Kobayashi Kaori, Kumon Yuka, Miyaji Fuyu, Nishimura Yushi, Oshimi Keisuke, Umehara Yumi, Teki Yoshio, Iwasaki Takayuki, Hatano Mutsuko, Hashimoto Hideki, Baba Yoshinobu

NANOSCALE ADVANCES 2 ( 5 ) 1859 - 1868 2020年5月

蛍光ナノダイヤモンドによる幹細胞再生機能温度センシング査読

宮地冬, 小林香央里, 西村勇姿, 藤原正澄, 湯川博, 馬場嘉信

一般社団法人日本臓器保存生物医学会 Organ Biology 27 ( 2 ) 185 - 190 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：(一社)日本臓器保存生物医学会

<p>It has become clear that temperature plays a major role in many life phenomena. However, little is known about the intracellular temperature, and the relationship between regenerative function and intracellular temperature of stem cells. In this study, fluorescent nanodiamond (FND) that can be applied as an excellent quantum sensor was used for stem cell labeling. Then, the relationship between the regenerative function of stem cells and the intracellular temperature of stem cells was evaluated by a sensing the optically detected magnetic resonance (ODMR) activity of NV centers in FNDs. FNDs could label adipose tissue-derived stem cells (ASCs) at high efficiency with 24 h incubation, and no cytotoxicity was observed in ASCs labeled with less than 500 µg/mL of FNDs. The ODMR of NV centers in FNDs was confirmed at approximately 2.87 GHz with a characteristic fluorescence spectrum, and the intracellular temperature of living ASCs during several days of culturing could be precisely measured. Moreover, the intracellular temperature was found to influence the production of growth factors and the degree of differentiation into adipocytes and osteocytes. These data suggest that NV centers in FNDs can be used to investigate the relationship between intracellular temperature and cellular functions.</p>

DOI： 10.11378/organbio.27.185

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Removing Non-Size-Dependent Electron Spin Decoherence of Nanodiamond Quantum Sensors by Aerobic Oxidation 査読

Tsukahara Ryuta, Fujiwara Masazumi, Sera Yoshihiko, Nishimura Yushi, Sugai Yuko, Jentgens Christian, Teki Yoshio, Hashimoto Hideki, Shikata Shinichi

ACS APPLIED NANO MATERIALS 2 ( 6 ) 3701 - 3710 2019年6月

Particle size effects of tetrahedron-shaped Ag3PO4 photocatalyst on water-oxidation activity and carrier recombination dynamics 査読

RyoMiyasato, MasazumiFujiwara, HaruyukiSato, ToshihiroYano, HidekiHashimoto

Chemical Physics Letters: X 2 100023 2019年4月

Monitoring spin coherence of single nitrogen-vacancy centers in nanodiamonds during pH changes in aqueous buffer solutions 査読

Masazumi Fujiwara, Ryuta Tsukahara, Yoshihiko Sera, Hiroshi Yukawa, Yoshinobu Baba, Shinichi Shikata, Hideki Hashimoto

RSC Advances 9 ( 22 ) 12606 - 12614 2019年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 The Royal Society of Chemistry. We report on the sensing stability of quantum nanosensors in aqueous buffer solutions for the two detection schemes of quantum decoherence spectroscopy and nanoscale thermometry. The electron spin properties of single nitrogen-vacancy (NV) centers in 25 nm-sized nanodiamonds have been characterized by observing individual nanodiamonds during a continuous pH change from 4 to 11. We have determined the stability of the NV quantum sensors during the pH change as the fluctuations of ±12% and ±0.2 MHz for the spin coherence time (T2) and the resonance frequency (ω0) of their mean values, which are comparable to the instrument error of the measurement system. We discuss the importance of characterizing the sensing stability during the pH change and how the present observation affects the measurement scheme of nanodiamond-based NV quantum sensing.

DOI： 10.1039/c9ra02282a

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Correlation between surface carrier dynamics and water oxidation activity of commercially available rutile-type TiO2 powders 査読

Miyasato Ryo, Fujiwara Masazumi, Sato Haruyuki, Yano Toshihiro, Hashimoto Hideki

CHEMICAL PHYSICS LETTERS 712 123 - 127 2018年11月

Observation of the linewidth broadening of single spins in diamond nanoparticles in aqueous fluid and its relation to the rotational Brownian motion 査読

Fujiwara Masazumi, Shikano Yutaka, Tsukahara Ryuta, Shikata Shinichi, Hashimoto Hideki

SCIENTIFIC REPORTS 8 14773 2018年10月

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