Wiley Acta Medica Okayama 0935-9648 2026 Turning Unpredictable Biomolecule Adsorption to Controlled Corona Formation: Focus on Carbon Nanomaterials e23328 EN Yajuan Zou Research Institute for Interdisciplinary Science, Okayama University Yalei Hu CNRS, Immunology Immunopathology and Therapeutic Chemistry University of Strasbourg ISIS Jie Yu Graduate School of Human and Environmental Studies, Kyoto University Naoki Komatsu Graduate School of Human and Environmental Studies, Kyoto University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Alberto Bianco Research Institute for Interdisciplinary Science, Okayama University With unique optical and physicochemical properties, carbon nanomaterials (CNMs), including carbon nanotubes, graphene-related materials, nanodiamonds, and carbon dots, are extensively explored as platforms for cancer diagnosis and treatment. However, in biofluids, CNMs spontaneously adsorb biomolecules to form an unpredictable corona, obstructing the implementation of their designed functions. In this review, we summarize how the intrinsic and acquired properties of CNMs affect protein corona formation, and the consequent biological and toxicological outcomes, as well as strategies to reshape the composition and structural organization of adsorbed proteins. This comprehensive knowledge will provide insights into developing CNMs with tailored corona and requested functions in cancer nanomedicine, advancing their translations into clinics. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2196-0216 13 8 2026 Electrochemical Synthesis of Benzo[b]Phosphole Oxides via Dehydrogenative Annulation Using 1,4-Diazabicyclo [2.2.2]Octane as a Mediator e70175 EN Koichi Mitsudo Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Sakura Kinjo Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuyuki Okumura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Riki Kato Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Graduate School of Environmental, Life, Natural Science and Technology, Okayama University The electrochemical intermolecular annulation of diarylphosphine oxides with alkynes for the synthesis of benzo[b]phosphole oxides has been reported. The reaction proceeded under transition-metal- and oxidant-free conditions via indirect electrolysis, using 1,4-diazabicyclo[2.2.2]octane as a mediator. High-surface-area carbon electrodes, such as carbon felt and reticulated vitreous carbon, are essential for this reaction. Several diarylphosphine oxides and alkynes were applied to electrochemical annulation, and the corresponding benzo[b]phosphole oxides were obtained. Mechanistic studies suggested that the reaction proceeds via radical intermediates generated through multiple pathways. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1472-6831 26 1 2026 Evaluation of contact-active antibacterial properties of cetylpyridinium chloride–graphene oxide coatings on dental restorative and titanium surfaces: an in vitro study 558 EN Keisuke Okubo Department of Periodontics and Endodontics, Field of Medical Development, Okayama University Gen Kano Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Masato Komoda Research Institute for Interdisciplinary Science, Okayama University Hideyuki Kamata Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin Nakamura Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuki Shinoda-Ito Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kazuhiro Omori Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Shogo Takashiba Department of Pathophysiology - Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objective Biofilm formation on dental restorative materials and implant surfaces plays a central role in the development of dental caries, periodontal disease, and peri-implantitis. Durable antimicrobial surface treatments that inhibit bacterial adhesion and biofilm formation remain a significant unmet need in restorative and implant dentistry. Therefore, this study aimed to develop a composite coating combining cetylpyridinium chloride and graphene oxide, and to evaluate its durable antibacterial surface modification under in vitro conditions.<br> Methods A composite coating consisting of cetylpyridinium chloride and graphene oxide was prepared and applied to composite resin and titanium surfaces. Antibacterial activity against Streptococcus mutans and Porphyromonas gingivalis was evaluated using adenosine triphosphate assays and fluorescence-based live/dead staining. Coating retention after washing and air-drying was assessed by optical microscopy and Raman spectroscopy.<br> Results Cetylpyridinium chloride-graphene oxide-coated surfaces showed a significant reduction in bacterial viability compared with phosphate-buffered saline, ethanol, and cetylpyridinium chloride-only controls. Antibacterial effects were maintained after rinsing and air-drying on both composite resin and titanium surfaces. Raman spectroscopy confirmed the persistence of characteristic graphene oxide bands after washing, indicating stable retention of the coating on the material surfaces.<br> Conclusions Cetylpyridinium chloride–graphene oxide coatings demonstrate sustained surface-associated antibacterial activity against key cariogenic and periodontal pathogens and remain stably adhered to common dental restorative and implant materials after washing. These findings suggest that cetylpyridinium chloride–graphene oxide coatings may serve as a durable contact-active surface modification strategy to reduce biofilm formation associated with dental caries and peri-implantitis. No potential conflict of interest relevant to this article was reported.

The Carbon Society of Japan Acta Medica Okayama 2436-5831 4 3 2025 Synthesis and applications of porous carbonaceous materials with inherited molecular structural features from the precursor molecules 179 187 EN Koki Chida Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Takeharu Yoshi Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Kazuhide Kamiya Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Ryota Sakamoto Department of Chemistry, Graduate School of Science, Tohoku University Fumito Tani Institute for Materials Chemistry and Engineering, Kyushu University Tomoki Ogoshi Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Hirotomo Nishihara Institute of Multidisciplinary Research for Advanced Materials, Tohoku University The carbonization of organic crystalline materials, such as metal organic frameworks and covalent organic frameworks, has emerged as a promising approach for producing functional porous carbonaceous materials. However, both the chemically defined long-term ordered structures and the local chemical structures derived from these precursor materials are generally lost, resulting in amorphous carbons. As a result, controlling the molecular-level structure of nanoporous carbons remains a significant challenge. We report a new bottom-up synthesis approach for porous carbons with a molecular-level design, involving the carbonization of well-designed precursor molecules by thermal polymerization. Among the resulting carbons, ordered carbonaceous frameworks, which contain a high-density of regularly aligned single-atomic metal species, have been identified as promising platforms for single-atom catalysts. This approach also enables the synthesis of various three-dimensional porous carbons that reflect the structural features of their precursor molecules. Recent progress in the synthesis and applications of porous carbons derived from molecular precursors is summarized, highlighting their potential for the development of functional materials. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2041-6520 17 9 2026 Gaseous CO2 electrolysis: latest advances in electrode and electrolyzer technologies toward abating CO2 emissions 4363 EN Kazuhide Kamiya Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Sora Nakasone Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Ryo Kurihara Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Asato Inoue Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Hazuki Irie Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Shoko Nakahata Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Satoshi Taniguchi Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 Thuy T. H. Nguyen Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 Sho Kataoka Research Institute for Chemical Process Technology, National Institute of Advanced Industrial Science and Technology (AIST), Central 5 The conversion of CO2 into multicarbon (C2+) products via electrochemical reduction is considered a key technology for the sustainable production of fuels and chemicals. The performance of high-rate gaseous CO2 electrolysis is governed by interrelated factors such as the electrocatalysts, electrodes, electrolytes, and cell architectures. Despite the intensive focus on catalyst research, systematic studies addressing the other components remain scarce, leaving critical gaps in our understanding toward achieving higher performance in CO2 electrolysis systems. The nanoscale design of catalyst surface electronic structures and the macroscale design of electrodes and electrolyzer architectures both influence the overall activity of the electrochemical system. In designing macroscale components, it is necessary to establish benchmarks based on a comprehensive evaluation of CO2 emissions for the entire electrolysis process, because these parameters are directly linked to output metrics such as current density and cell voltage under practical operating conditions. This review summarizes recent advances in electrodes and electrolyzers, and through life-cycle assessment (LCA), evaluates key performance indicators (KPIs) for achieving negative emissions and assesses the current technology readiness of CO2 electrolysis. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1759-9954 16 47 2025 Synthesis of sterically unhindered Lewis acidic boron-doped ƒÎ-conjugated polymers 5035 5039 EN Naoki Takahashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University We report the synthesis of sterically unhindered boron-doped ƒÎ-conjugated polymers via polymerization of organo-dilithium reagents with boron trichloride. The resulting polymer exhibits Lewis acidity and catalyzes the transesterification of methyl benzoate. This performance is attributed to the electron-accepting ability, and thermally labile Lewis acid–base interactions, facilitating catalytic turnover. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1613-6810 2025 Atomic-Level Insights into Thermal Carbonization of Ethynyl-Containing Boron Compounds e13537 EN Kentaro Ohkura Research Institute for Interdisciplinary Science, Okayama University Satoshi Hayakawa Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University Naoki Takahashi Graduate School of Environment Life Natural Science and Technology, Okayama University Ken Yamazaki Graduate School of Environment Life Natural Science and Technology, Okayama University Jun Kano Graduate School of Environment Life Natural Science and Technology, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University This study reports the design, synthesis, and characterization of boron-doped carbon (BDC) derived from a triethynylborane-pyridine complex. Triethynylborane is stabilized by coordination with pyridine, facilitating its synthesis and handling in ambient conditions. The complex is subjected to thermal treatment at various temperatures to form BDC. Powder XRD and single-crystal XRD analyses reveal that BDC prepared at 200 ‹C retains an ordered structure, while higher temperatures induce alkyne structural changes without significant weight or surface area alterations. Coin cells are assembled using BDC as the anode, demonstrating unique Li-ion and Na-ion storage properties distinct from graphite. These results suggest that the BDC reflects the precursor's crystal structure, enabling novel electrochemical behavior. These findings offer insight into the development of advanced BDC materials for energy storage applications. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1439-0108 2025 Coupling effects of biochar and sediment microbial fuel cells on CH4 and CO2 emissions from straw-amended paddy soil EN Adhena Tesfau Bekele Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Morihiro Maeda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Nakahara Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Ayumi Hashiguchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroaki Somura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Satoshi Akao Faculty of Science and Engineering, Doshisha University Chiyu Nakano Department of Comprehensive Technical Solutions, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Purpose The independent incorporation of biochar and sediment microbial fuel cells (SMFCs) into paddy soil has been shown to reduce methane (CH4) emissions. However, the application of rice straw into paddy soil enhances the availability of labile carbon that stimulates methanogen growth, counteracting the mitigation effects of both methods. This study, therefore, aimed to investigate the effect of coupling biochar and SMFC on CH4 and CO2 emissions from straw-amended paddy soil.<br> Materials and methods Single chamber SMFC setups constructed using acrylic columns (height, 25 cm; inner diameter, 9 cm) with six treatments were established using soil amended with 0% (0BC), 1% (1BC), and 2% (2BC) biochar: with and without SMFC conditions. Stainless steel mesh (15 ~ 3 cm) and graphite felt (6 ~ 5 cm) were used as anode and cathode materials, respectively.<br> Results Cumulative emission of CH4 in the 0BC treatment with SMFC was 39% less than in that without SMFC. Biochar addition and SMFC operation together further reduced CH4 emission by 57% and 60% in 1BC and 2BC treatments, respectively, compared to that in the 0BC treatment without SMFC operation. The relative abundance of microbial communities indicated methane-oxidizing bacteria were enriched in the presence of biochar and hydrogenotrophic Methanoregula were suppressed by SMFC operation. This suggested that SMFC mainly inhibited CH4 production by outcompeting hydrogenotrophic archaea.<br> Conclusion The use of biochar made from leftover rice straw has an interactive effect on SMFC operation and both methods can be used to reduce CH4 emission from straw-amended paddy soil. No potential conflict of interest relevant to this article was reported.

Japan Society on Water Environment Acta Medica Okayama 1348-2165 23 5 2025 Biochar-amended Sediment Microbial Fuel Cells for Water Quality Improvement in Intensive and Extensive Pond Drainages in Central Vietnam 234 249 EN Uyen Tu Nguyen Graduate School of Environmental and Life Science, Okayama University Morihiro Maeda Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Hiroaki Somura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Nozomi Nakahara Department of Comprehensive Technical Solutions, Okayama University Gamamada Liyanage Erandi Priyangika Perera Graduate School of Environmental and Life Science, Okayama University Chiyu Nakano Graduate School of Environmental and Life Science, Okayama University Huu Tien Le Department of Education, Science and Technology Quang Tri Branch, Hue University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University The use of nutrient-rich feed in shrimp farming in Central Vietnam has led to high nitrogen (N) and phosphorus (P) contents in the pond sediment. The objectives of the study were to assess the effectiveness of biochar-sediment microbial fuel cells (BC-SMFCs) in suppressing P and N release from two types of sediment in intensive (Int) and extensive (Ext) pond drainages in Central Vietnam. Single chamber SMFCs were set up and operated under open or closed-circuit (no SMFC or SMFC) conditions. Coconut shell biochar (BC) was amended to sediments at 1%. For Int-sediment, total phosphorus (TP) release was reduced by no BC-SMFCs through co-precipitation with Fe. On the other hand, BC-SMFCs did not suppress TP release because P was released from BC and organic matter decomposition was enhanced in the sediment. Application of BC enhanced organic N mineralization in the sediment. Nitrification and denitrification occurred in the overlying water, reducing mineral N concentrations. For Ext-sediment, BC addition and SMFC conditions did not affect TP and total nitrogen (TN) release because of low initial organic matter content, and less reductive condition. Our study suggested that the effect of SMFCs was masked by BC which released more P from Int-sediment to the water. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2050-7488 13 35 2025 Thermally polymerizable phthalocyanine realizes a metal–nitrogen-doped carbon material featuring a defined single-atom catalyst motif with CO2RR activity 28887 28895 EN Yuki Sano Department of Chemistry, Graduate School of Science, Tohoku University Daichi Nakajima Department of Chemistry, Graduate School of Science, Tohoku University Biplab Manna Center for Basic Research on Materials, National Institute for Materials Science Koki Chida Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Ryojun Toyoda Department of Chemistry, Graduate School of Science, Tohoku University Shinya Takaishi Department of Chemistry, Graduate School of Science, Tohoku University Kazuyuki Iwase Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Koji Harano Center for Basic Research on Materials, National Institute for Materials Science Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Takeharu Yoshii Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Ryota Sakamoto Department of Chemistry, Graduate School of Science, Tohoku University Metal–nitrogen-doped carbon materials (MNCs) exhibit good electrocatalytic performance owing to the intrinsic advantages of carbon-based materials and the presence of isolated and stabilized metal atoms coordinated by nitrogen sites. However, conventional high-temperature pyrolysis of precursor molecules make it difficult to control the coordination structure precisely. To address this issue, here we report a new synthesis strategy for MNCs. Specifically, we design and synthesize Ni-phthalocyanine functionalized with ethynyl groups as solid-state thermal polymerization points. After depositing the Ni-phthalocyanine precursor on a carbon support and performing a thermal treatment, the resultant carbon composite material features a Ni–N4 coordination structure derived from the precursor, and enhanced porosity. This material demonstrates high catalytic activity for the CO2 reduction reaction (CO2RR). Our synthetic approach is applicable to various precursor molecules and carbon supports, paving the way for the further development of MNC-based electrode catalysts. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 243 2025 Organic solvent transport through reduced graphene oxide membranes with controlled oxygen content 120539 EN Hongzhe Chen School of Materials Science and Engineering, University of New South Wales Sydney Tongxi Lin School of Materials Science and Engineering, University of New South Wales Sydney Zeno Rizqi Ramadhan Electron Microscope Unit, University of New South Wales Aditya Rawal Mark Wainwright Analytical Centre, University of New South Wales Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Amir Karton School of Science and Technology, University of New England Xiaojun Ren School of Materials Science and Engineering, University of New South Wales Sydney Rakesh Joshi School of Materials Science and Engineering, University of New South Wales Sydney Recent advances in membranes based on 2-dimensional (2D) materials have enabled precise control over angstrom-scale pores, providing a unique platform for studying diverse mass transport mechanisms. In this work, we systematically investigate the transport of solvent vapors through 2D channels made of graphene oxide (GO) laminates with precisely controlled oxygen content. Using in-situ chemical reduction of GO with vitamin C, we fabricated reduced GO membranes (VRGMs) with oxygen content systematically decreased from 31.6 % (pristine GO) to 24.0 % (VRGM-maximum reduction). Vapor permeability measurements showed a distinct correlation between oxygen functional groups and solvent transport behaviour. Specifically, non-polar hexane exhibits 114 % of enhanced permeance through the reduced membranes with larger graphitic domains, while the permeance of water decreases by 55 %. With the support of density functional theory (DFT) simulations, we modelled the hydrogen-bond and dispersion complexes between the solvents and GO and calculated the complexation energies. The simulation results suggest that polar molecules interact with the oxygen functional groups of GO via a hydrogen-bond network, supporting in-plane transport. In contrast, van der Waals forces drive the transport of low-polarity solvents along the graphitic domains of the 2D channel in reduced GO membranes. Our findings provide potential strategies for future design of organic solvent nanofiltration membranes. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 2053-1583 12 4 2025 Covalent cross-linked graphene oxide aerogels for moisture adsorption 045010 EN Zhijian Cao School of Materials Science and Engineering, University of New South Wales Xiaojun Ren School of Materials Science and Engineering, University of New South Wales Tongxi Lin School of Materials Science and Engineering, University of New South Wales Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Masamichi Yoshimura Graduate School of Engineering, Toyota Technological Institute Rakesh Joshi School of Materials Science and Engineering, University of New South Wales Covalent cross-linking is an effective approach to enhance the hydrophilicity and water adsorption properties of graphene oxide (GO). We studied moisture absorption in GO cross-linked with poly(ethylene glycol) diamines. At relative humidity (RH) of 85%, the PEG-cross-linked GO exhibited a significantly enhanced water uptake capacity of 0.59 g of water per gram of GO (gg|1), compared to 0.37 for unmodified GO. This is attributed to the presence of alkoxy groups via cross-linking, resulting in the enhanced interaction between GO and water molecules. These findings highlight the potential of PEG-based covalent functionalisation for efficient moisture capture in GO-based materials. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2694-2496 2025 RNA Delivery Using a Graphene Oxide-Polyethylenimine Hybrid Inhibiting Myotube Differentiation EN Koji Matsuura CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Giacomo Reina CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Zhengfeng Gao CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Alberto Bianco CNRS, Immunology, Immunopathology and Therapeutic Chemistry, UPR3572, University of Strasbourg, ISIS Graphene oxide (GO) conjugated with short polyethylenimine (PEI) chains (GO-PEI) has been designed as a candidate nanocarrier for small interfering RNA (siRNA) delivery to mammalian cells based on the efficient interaction between the positively charged GO-based platform and the negatively charged siRNA. The function and efficiency of siRNA delivery using GO-PEI were compared to those using the positive control Lipofectamine RNAiMax by analyzing the differentiation to myotubes, and myogenin gene and protein expression in C2C12 cells. RNAiMax transfection induced cellularization and reduction of both myogenin gene and protein expression, suggesting that the differentiation of C2C12 cells was triggered by gene silencing. While GO-PEI also promoted cellularization, the myogenin gene expression remained comparable to scrambled controls, whereas the protein levels were higher than those observed with RNAiMax. Mechanistically, we attributed the reduced gene silencing efficiency of GO-PEI to a poor endosomal escape, despite strong siRNA complexation. This limitation was likely due to a low buffering capacity of GO-PEI, as a significant fraction of nitrogen atoms were already protonated, reducing the availability of free amines necessary for endosomal disruption. An appropriate chemical modification to enhance siRNA release from the endosomes is therefore essential for advancing the development of GO-based platforms as versatile and efficient nanocarriers in gene therapy applications. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2640-4567 2025 Integration of Cholesterol Oxidase]Based Biosensors on a Smart Contact Lens for Wireless Cholesterol Monitoring from Tears 2500368 EN Yang Cui Graduate school of Information, Production and Systems, Waseda University Lin Zhuo Graduate school of Information, Production and Systems, Waseda University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Saman Azhari Graduate school of Information, Production and Systems, Waseda University Takeo Miyake Graduate school of Information, Production and Systems, Waseda University Cholesterol plays a critical role in physiological functions, but elevated levels increase the risk of cardiovascular disease. Regular cholesterol monitoring is essential for elderly or obese individuals. Current methods, such as blood tests, are invasive, inconvenient, and require a professional operator. In contrast, tears, as an accessible body fluid, offer a promising alternative for noninvasive monitoring due to their correlation with blood cholesterol levels. Herein, a noninvasive approach for monitoring cholesterol levels in tears using a biosensor integrated into a smart contact lens is reported. The biosensor employs cholesterol oxidases as the biocatalyst, coupled with an osmium-based mediator, to detect cholesterol concentrations ranging from 0.1 mM to 1.2 mM in artificial tears. A key challenge is the extremely low cholesterol concentration in tears, which is addressed using a parity-time (P-T) symmetry-based magnetic resonance coupling system. This system enables wireless signal reading and achieves high sensitivity due to its high-quality (Q) factor, which can achieve a detection limit of 0.061 mM. This portable, high-sensitivity smart contact lens demonstrates significant potential as a wearable device for continuous, noninvasive cholesterol monitoring. The findings contribute to advancing tear-based diagnostic systems and highlight the scientific importance of utilizing tear biomarkers for health monitoring. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0956-5663 287 2025 A plant-insertable multi-enzyme biosensor for the real-time monitoring of stomatal sucrose uptake 117674 EN Shiqi Wu Graduate School of Information, Production and Systems, Waseda University Wakutaka Nakagawa Graduate School of Information, Production and Systems, Waseda University Yuki Mori Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu Saman Azhari Graduate School of Information, Production and Systems, Waseda University Gábor Méhes Graduate School of Information, Production and Systems, Waseda University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Tomonori Kawano Faculty and Graduate School of Environmental Engineering, The University of Kitakyushu Takeo Miyake Graduate School of Information, Production and Systems, Waseda University Monitoring sucrose transport in plants is essential for understanding plant physiology and improving agricultural practices, yet effective sensors for continuous and real-time in-vivo monitoring are lacking. In this study, we developed a plant-insertable sucrose sensor capable of real-time sucrose concentration monitoring and demonstrated its application as a useful tool for plant research by monitoring the sugar-translocating path from leaves to the lower portion of plants through the stem in living plants. The biosensor consists of a bilirubin oxidase-based biocathode and a needle-type bioanode integrating glucose oxidase, invertase, and mutarotase, with the two electrodes separated by an agarose gel for ionic connection. The sensor exhibits a sensitivity of 6.22 ƒÊA mM|1 cm|2, a limit of detection of 100 ƒÊM, a detection range up to 60 mM, and a response time of 90 s at 100 ƒÊM sucrose. Additionally, the sensor retained 86 % of its initial signal after 72 h of continuous measurement. Day-night monitoring from the biosensor inserted in strawberry guava (Psidium cattleianum) showed higher sucrose transport activity at night, following well the redistribution of photosynthetically produced sugars. In addition, by monitoring the forced translocation of sucrose dissolved in the stable isotopically labeled water, we demonstrated that a young seedling of Japanese cedar known as Sugi (Cryptomeria japonica) can absorb and transport both water and sucrose through light-dependently opened stomata, which is the recently revealed path for liquid uptake by higher plants. These findings highlight the potential of our sensor for studying dynamic plant processes and its applicability in real-time monitoring of sugar transport under diverse environmental conditions. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1613-6810 2025 Polyglycerol]Grafted Graphene Oxide with pH]Responsive Charge]Convertible Surface to Dynamically Control the Nanobiointeractions for Enhanced in Vivo Tumor Internalization 2503029 EN Yajuan Zou Research Institute for Interdisciplinary Science, Okayama University Alberto Bianco Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University pH-responsive charge-convertible nanomaterials (NMs) ameliorate the treatment of cancer via simultaneously reducing nonspecific interactions during systemic circulation and improving targeted uptake within solid tumors. While promising, little is known about how the pH-responsiveness of charge-convertible NMs directs their interactions with biological systems, leading to compromised performance, including off-target retention and low specificity to tumor cells. In the present study, polyglycerol-grafted graphene oxide bearing amino groups (GOPGNH2) at different densities are reacted with dimethylmaleic anhydride (DMMA), a pH-responsive moiety, to generate a set of charge-convertible GOPGNH-DMMA variants. This permits the assessment of a quantitative correlation between the structure of GOPGNH-DMMA to their pH-responsiveness, their dynamic interactions with proteins and cells, as well as their in vivo biological fate. Through a systematic investigation, it is revealed that GOPGNH115-DMMA prepared from GOPGNH2 with higher amine density experienced fast charge conversion at pH 7.4 to induce non-specific interactions at early stages, whereas GOPGNH60-DMMA and GOPGNH30-DMMA prepared from lower amine density retarded off-target charge conversion to enhance tumor accumulation. Notably, GOPGNH60-DMMA is also associated with enough amounts of proteins under acidic conditions to promote in vivo tumor internalization. The findings will inform the design of pH-responsive NMs for enhanced treatment accuracy and efficacy. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2192-2640 14 10 2024 Biocompatibility of Water-Dispersible Pristine Graphene and Graphene Oxide Using a Close-to-Human Animal Model: A Pilot Study on Swine 2401783 EN Paola Nicolussi Istituto Zooprofilattico Sperimentale della Sardegna Giovannantonio Pilo Istituto Zooprofilattico Sperimentale della Sardegna Maria Giovanna Cancedda Istituto Zooprofilattico Sperimentale della Sardegna Guotao Peng Institute of Environmental Medicine, Karolinska Institutet Ngoc Do Quyen Chau CNRS, Immunology, Immunopathology and Therapeutic Chemistry Alejandro De la Cadena Dipartimento di Fisica, Politecnico di Milano Renzo Vanna Istituto di Fotonica e Nanotecnologie – CNR Yarjan Abdul Samad Cambridge Graphene Centre, University of Cambridge Tanweer Ahmed Cambridge Graphene Centre, University of Cambridge Jeremia Marcellino Cambridge Graphene Centre, University of Cambridge Giuseppe Tedde Istituto Zooprofilattico Sperimentale della Sardegna Linda Giro ImmuneNano Laboratory, Department of Biomedical Sciences Acelya Ylmazer Department of Biomedical Engineering, Ankara University Federica Loi Istituto Zooprofilattico Sperimentale della Sardegna Gavina Carta Istituto Zooprofilattico Sperimentale della Sardegna Loredana Secchi Istituto Zooprofilattico Sperimentale della Sardegna Silvia Dei Giudici Istituto Zooprofilattico Sperimentale della Sardegna Simona Macciocu Istituto Zooprofilattico Sperimentale della Sardegna Dario Polli Dipartimento di Fisica, Politecnico di Milano Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Ciriaco Ligios Istituto Zooprofilattico Sperimentale della Sardegna Giulio Cerullo Dipartimento di Fisica, Politecnico di Milano Andrea Ferrari Cambridge Graphene Centre, University of Cambridge Alberto Bianco CNRS, Immunology, Immunopathology and Therapeutic Chemistry Bengt Fadeel Institute of Environmental Medicine, Karolinska Institutet Giulia Franzoni Istituto Zooprofilattico Sperimentale della Sardegna Lucia Gemma Delogu ImmuneNano Laboratory, Department of Biomedical Sciences Graphene-based materials (GBMs) are of considerable interest for biomedical applications, and the pilot study on the toxicological and immunological impact of pristine graphene (GR) and graphene oxide (GO) using swine as a close-to-human provides valuable insights. First, ex vivo experiments are conducted on swine blood cells, then GBMs are injected intraperitoneally (i.p.) into swine. Hematological and biochemical analyses at various intervals indicate that neither GO nor GR cause systemic inflammation, pro-coagulant responses, or renal or hepatic dysfunction. Importantly, no systemic toxicity is observed. Analysis of a panel of 84 immune-related genes shows minimal impact of GO and GR. The animals are sacrificed 21 days post-injection, and transient absorption imaging and Raman mapping show the presence of GO and GR in the mesentery only. Histological evaluation reveals no signs of alterations in other organs. Thus, clusters of both materials are detected in the mesentery, and GO aggregates are surrounded only by macrophages with the formation of granulomas. In contrast, modest local reactions are observed around the GR clusters. Overall, these results reveal that i.p. injection of GBMs resulted in a modest local tissue reaction without systemic toxicity. This study, performed in swine, provides essential guidance for future biomedical applications of graphene. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2694-2496 4 4 2024 Light-Responsive and Antibacterial Graphenic Materials as a Holistic Approach to Tissue Engineering 263 272 EN Andrea Ferreras Department of Bioengineering, Universidad Carlos III de Madrid Ana Matesanz Department of Electronic Technology, Universidad Carlos III de Madrid Jabier Mendizabal Domotek ingeniería prototipado y formación S.L. Koldo Artola Domotek ingeniería prototipado y formación S.L. Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Pablo Acedo Department of Electronic Technology, Universidad Carlos III de Madrid José L. Jorcano Department of Bioengineering, Universidad Carlos III de Madrid Amalia Ruiz Institute of Cancer Therapeutics, School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford Giacomo Reina Empa Swiss Federal Laboratories for Materials Science and Technology Cristina Martín Department of Bioengineering, Universidad Carlos III de Madrid While the continuous development of advanced bioprinting technologies is under fervent study, enhancing the regenerative potential of hydrogel-based constructs using external stimuli for wound dressing has yet to be tackled. Fibroblasts play a significant role in wound healing and tissue implants at different stages, including extracellular matrix production, collagen synthesis, and wound and tissue remodeling. This study explores the synergistic interplay between photothermal activity and nanomaterial-mediated cell proliferation. The use of different graphene-based materials (GBM) in the development of photoactive bioinks is investigated. In particular, we report the creation of a skin-inspired dressing for wound healing and regenerative medicine. Three distinct GBM, namely, graphene oxide (GO), reduced graphene oxide (rGO), and graphene platelets (GP), were rigorously characterized, and their photothermal capabilities were elucidated. Our investigations revealed that rGO exhibited the highest photothermal efficiency and antibacterial properties when irradiated, even at a concentration as low as 0.05 mg/mL, without compromising human fibroblast viability. Alginate-based bioinks alongside human fibroblasts were employed for the bioprinting with rGO. The scaffold did not affect the survival of fibroblasts for 3 days after bioprinting, as cell viability was not affected. Remarkably, the inclusion of rGO did not compromise the printability of the hydrogel, ensuring the successful fabrication of complex constructs. Furthermore, the presence of rGO in the final scaffold continued to provide the benefits of photothermal antimicrobial therapy without detrimentally affecting fibroblast growth. This outcome underscores the potential of rGO-enhanced hydrogels in tissue engineering and regenerative medicine applications. Our findings hold promise for developing game-changer strategies in 4D bioprinting to create smart and functional tissue constructs with high fibroblast proliferation and promising therapeutic capabilities in drug delivery and bactericidal skin-inspired dressings. No potential conflict of interest relevant to this article was reported.

Japan Society on Water Environment Acta Medica Okayama 1348-2165 22 6 2024 Effects of Sediment Microbial Fuel Cells on CH4 and CO2 Emissions from Straw Amended Paddy Soil 271 285 EN Adhena Tesfau Bekele Graduate School of Environmental and Life Science, Okayama University Morihiro Maeda Graduate School of Environmental and Life Science, Okayama University Satoshi Akao Faculty of Science and Engineering, Doshisha University Hiroaki Somura Graduate School of Environmental and Life Science, Okayama University Chiyu Nakano Organization for Research Strategy and Development, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Straw returning into paddy soil enhances soil organic matter which usually promotes the emission of greenhouse gases to the atmosphere. The application of sediment microbial fuel cells (SMFCs) to paddy soil activates power-generating microorganisms and enhances organic matter biodegradation. In the present study, rice straw addition in SMFCs was examined to determine its effect on CH4 and CO2 emissions. Columns (height, 25 cm; inner diameter, 9 cm) with four treatments: soil without and with rice straw under SMFC and without SMFC conditions were incubated at 25‹C for 70 days. Anodic potential values at 7 cm depth sediment were kept higher by SMFCs than those without SMFCs. Cumulative CH4 emission was significantly reduced by SMFC with straw amendment (p < 0.05) with no significant effect on CO2 emission. 16S rRNA gene analysis results showed that Firmicutes at the phylum, Closteridiales and Acidobacteriales at order level were dominant on the anode of straw-added SMFC, whereas Methanomicrobiales were in the treatment without SMFC, indicating that a certain group of methanogens were suppressed by SMFC. Our results suggest that the anodic redox environment together with the enrichment of straw-degrading bacteria contributed to a competitive advantage of electrogenesis over methanogenesis in straw-added SMFC system. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2470-1343 9 34 2024 Engineering Zeolitic-Imidazolate-Framework-Derived Mo-Doped Cobalt Phosphide for Efficient OER Catalysts 36114 36121 EN Mohammad Atiqur Rahman Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Ze Cai Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Zannatul Mumtarin Moushumy Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University Ryuta Tagawa Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yoshiharu Hidaka Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Chiyu Nakano Research Core for Interdisciplinary Sciences, Okayama University Md. Saidul Islam Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yoshihiro Sekine Department of Chemistry, Graduate School of Science and Technology, Kumamoto University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Shintaro Ida Institute of Industrial Nanomaterials (IINa), Kumamoto University Shinya Hayami Institute of Industrial Nanomaterials (IINa), Kumamoto University Designing a cheap, competent, and durable catalyst for the oxygen evolution reaction (OER) is exceedingly necessary for generating oxygen through a water-splitting reaction. In this project, we have designed a ZIF-67-originated molybdenum-doped cobalt phosphide (CoP) using a simplistic dissolution–regrowth method using Na2MoO4 and a subsequent phosphidation process. This leads to the formation of an exceptional hollow nanocage morphology that is useful for enhanced catalytic activity. Metal–organic frameworks, especially ZIF-67, can be used both as a template and as a metal (cobalt) precursor. Molybdenum-doped CoP was fabricated through a two-step synthesis process, and the fabricated Mo-doped CoP showed excellent catalytic activity during the OER with a lower value of overpotential. Furthermore, the effect of the Mo amount on the catalytic activity has been explored. The best catalyst (CoMoP-2) showed an onset potential of around 1.49 V at 10 mA cm–2 to give rise to a Tafel slope of 62.1 mV dec–1. The improved catalytic activity can be attributed to the increased porosity and surface area of the resultant catalyst. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 238 2025 Grafting-through functionalization of graphene oxide with cationic polymers for enhanced adsorption of anionic dyes and viruses 120296 EN Ryota Kimura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Pilar Ferré-Pujol Research Core for Interdisciplinary Sciences, Okayama University Yuta Nishina Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Graphene oxide (GO) is a sheet-like carbon material with abundant oxygen-containing functional groups on its surface. GO has been extensively studied as an adsorbent for heavy metals and organic compounds. However, effective strategies for negatively charged materials have yet to be established. This study aimed to synthesize composites of GO and cationic polymers for the selective adsorption of negatively charged materials; a challenge in this approach is the strong electrostatic interactions between GO and cationic polymers, which can lead to aggregation. This study addresses this issue by employing the grafting-through method. GO was initially modified with allylamine to introduce a polymerizable site, followed by radical polymerization to covalently bond polymers to the GO surface, effectively preventing aggregation. Adsorption experiments demonstrated that the GO-polymer composite selectively adsorbs anionic dye, such as methyl orange. Virus adsorption tests showed significantly enhanced performance compared to pristine GO. These results emphasize the critical role of controlled surface modification and charge manipulation in optimizing the adsorption performance of GO. This study establishes a simple and effective approach for synthesizing GO-cationic polymer composites, contributing to the development of advanced materials for water purification applications. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 60 76 2024 Investigating the radical properties of oxidized carbon materials under photo-irradiation: behavior of carbon radicals and their application in catalytic reactions 10544 10547 EN Md Razu Ahmed Research Institute for Interdisciplinary Science, Okayama University Israel Ortiz Anaya Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Oxidized carbon materials have abundant surface functional groups and customizable properties, making them an excellent platform for generating radicals. Unlike reactive oxygen species such as hydroxide or superoxide radicals that have been reported previously, oxidized carbon also produces stable carbon radicals under photo-irradiation. This has been confirmed through electron spin resonance. Among the various oxidized carbon materials synthesized, graphene oxide shows the largest number of carbon radicals when exposed to blue LED light. The light absorption capacity, high surface area, and unique structural characteristics of oxidized carbon materials offer a unique function for radical-mediated oxidative reactions. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0021-9797 695 2025 Tunable interlayer distance in graphene oxide through alkylamine surface coverage and chain length 137727 EN Israel Ortiz-Anaya Graduate School of Natural Sciences and Technology, Okayama University Seiji Obata Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Layered materials have unique structures that can be modified by adjusting the space between layers through pillaring or surface functionalization. Unlike typical crystalline layered materials, graphene oxide (GO) possesses reactive oxygenated functional groups, which lead to spontaneous reduction and stacking upon thermal treatment. Here, we investigated the functionalization of GO with different amounts of hexylamine to control the degree of surface coverage. Furthermore, octylamine and dodecylamine were employed to confirm the effect of the alkyl chain length on the interlayer distance of the resultant GO derivatives. Subsequent thermal treatment produced reduced GO (rGO) functionalized with alkylamines, demonstrating the retention of the interlayer distance. Additionally, amine-functionalized rGOs exhibited varying porous structures. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 234 2025 Reversible chemical modifications of graphene oxide for enhanced viral capture and release in water 120015 EN Pilar Ferré-Pujol Research Institute for Interdisciplinary Science, Okayama University Seiji Obata Research Institute for Interdisciplinary Science, Okayama University Jésus Raya Institut de Chimie, UMR 7177 CNRS, Université de Strasbourg Alberto Bianco Research Institute for Interdisciplinary Science, Okayama University Hiroyuki Katayama Department of Urban Engineering, School of Engineering, The University of Tokyo Takashi Kato Research Center for Water Environment Technology, School of Engineering, The University of Tokyo Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Detecting low concentrations of viruses in sewage water is crucial for monitoring the spread of emerging viral diseases. However, current detection methods, which involve concentrating viruses using traditional materials such as gauze or cotton, have limitations in effectively accomplishing this task. This study demonstrates that graphene oxide (GO), a two-dimensional carbon material, possesses strong viral adsorption capabilities. However, it lacks efficiency for effective viral release. Therefore, we designed a series of new GO-based materials, which exhibited a viral adsorption similar to pristine GO, while significantly enhancing their release performance by attaching alkyl chains and hydrophilic functional groups. Among the synthesized materials, 1,8-aminooctanol grafted to GO (GO-NH2C8OH) has emerged as the most promising candidate, achieving a viral release rate higher than 50 %. This superior performance can be attributed to the synergistic effect of the alkyl chain and the terminal OH group, which enhances both its affinity for viruses and water dispersibility. Furthermore, we have successfully applied GO-NH2C8OH in a new protocol for concentrating viruses from sewage wastewater. This approach has demonstrated a 200-fold increase in virus concentration, allowing PCR detection of this type of pathogens present in wastewater below the detection limit by direct analysis, underscoring its significant potential for virus surveillance. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0947-6539 31 14 2025 Graphene Oxide as a Self]Carbocatalyst to Facilitate the Ring]Opening Polymerization of Glycidol for Efficient Polyglycerol Grafting e202404400 EN Yajuan Zou Research Institute for Interdisciplinary Science, Okayama University Kentaro Ohkura Graduate School of Natural Science and Technology, Okayama University Israel Ortiz]Anaya Research Institute for Interdisciplinary Science, Okayama University Ryota Kimura Graduate School of Natural Science and Technology, Okayama University Alberto Bianco Research Institute for Interdisciplinary Science, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Grafting carbon-based nanomaterials (CNMs) with polyglycerol (PG) improves their application potentials in biomedicine and electronics. Although ggrafting fromh method offers advantages over ggrafting toh one in terms of operability and versatility, little is known about the reaction process of glycidol with the surface groups onto CNMs. By using graphene oxide (GO) as a multi-functional model material, we examined the reactivity of the surface groups on GO toward glycidol molecules via a set of model reactions. We reveal that carboxyl groups spontaneously react with the epoxide ring with no need of catalyst, while GO catalyzes the reactions of hydroxyl groups with the epoxide of glycidol. In addition, the hydroxyl group of glycidol can open the epoxide in the basal plane of GO. The subsequent polymerization of PG is supposed to propagate at the primary and/or the secondary hydroxyl groups, generating a ramified PG macromolecule with random branch-on-branch topology. In addition, ketones, benzyl esters and aromatic ethers are found not to react with glycidol even in the presence of GO, while the aldehydes are easily oxidized into carboxyl groups under ambient condition, behaving then as the carboxyl groups. Our findings pose the foundation for understanding the polymerization mechanism of PG on CNMs. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1936-0851 18 49 2024 Mass Production of Graphene Oxide Beyond the Laboratory: Bridging the Gap Between Academic Research and Industry 33264 33275 EN Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University The mass production of graphene oxide (GO) has garnered significant attention in recent years due to its potential applications in various fields, from materials science to biomedicine. Graphene, known for its unique properties, such as high conductivity and mechanical strength, has been extensively studied. However, traditional production methods such as the exfoliation of graphite with scotch tape are not suitable for large-scale production. This has led to an increased focus on GO as a viable alternative to graphene production. Nonetheless, challenges, including the optimization of oxidation processes, the control of structural uniformity, and the reproducibility of production, have not been solved so far. This review critically examines GO production advancements by analyzing experimental and mechanistic studies to identify significant developments that enable high-yield and reproducible methods suitable for industrial-scale production. Special attention is given to oxidation techniques and postsynthesis purification and storage, with a focus on controlled oxidation to achieve homogeneous and single-layer GO. Through this lens, the review outlines the path forward for the industrialization of GO, aiming to bridge the gap between academic research and industrial production. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 0009-2673 97 11 2024 Refined surface area determination of graphene oxide using methylene blue as a probe molecule: a comparative approach uoae118 EN Israel Ortiz-Anaya Graduate School of Natural Sciences and Technology, Okayama University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University In this research, we explored the effectiveness of the methylene blue adsorption method as an alternative approach for determining the specific surface area of graphene oxide. Initially, through a comparative analysis with reference activated carbon, we identified the limitations of utilizing N2 physisorption for specific surface area determination of graphene oxide. Our findings revealed that the standard pretreatment process (heating under vacuum) before N2 physisorption led to damage to the surface oxygen groups on graphene oxide, and the measured surface areas (43 m2/g) do not accurately represent the entire surface area. To optimize methylene blue coverage on graphene oxide, we conducted adsorption equilibrium experiments, focusing on controlling temperature and pH. The pH was significantly important in regulating the coverage of methylene blue. Under the optimized methylene blue adsorption conditions, the specific surface area of graphene oxide was 1,555 m2/g. Our assumptions regarding specific surface area calculations were supported by structural characterization of samples with varying methylene blue uptakes. The results confirmed a uniform coverage of methylene blue on graphene oxide by scanning electron microscopy and energy dispersive X-ray, X-ray diffraction, and atomic force microscopy. No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0003-6951 125 2 2024 Enhanced thermal conductivity of fluids by percolating high-concentration few-layer graphene 023104 EN Keiko Ishii College of Science and Engineering, Chuo University Takahiro Ogiyama College of Science and Engineering, Aoyama Gakuin University Koji Fumoto College of Science and Engineering, Aoyama Gakuin University Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University High-performance and small-sized heat exchangers have been demanded due to the miniaturization and higher output of electronic devices, lasers, and energy harvesting/storage systems. Graphene nanosheet suspension has attracted attention as a next-generation nanofluid because of its high thermal conductivity and low pressure drop, while being dispersed stably without any additives. Graphene-based nanofluids have been mostly investigated using graphene oxide, and there are a few studies on pure graphene because of the limitation in mass production and stabilization at high concentrations of graphene. In this study, we prepared a 10 wt. % high-concentration few-layer graphene suspension by pulverizing graphite particles. Scanning electron microscopy, atomic force microscopy, and Raman spectra confirmed the few-layer graphene is formed in the suspension. The thermal conductivity of the suspension increased with concentration and suddenly jumped at a specific concentration. Furthermore, a significant improvement in thermal conductivity of >40% compared to base liquid was confirmed at 10 wt. % graphene content. A similar trend was observed for electrical resistance; 10 wt. % graphene suspension showed 62% lower resistance than that of 1 wt. %. These results suggest the percolation of graphene in a liquid, which has not been observed for graphene-based materials in previous research. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0045-6535 358 2024 Size, polyglycerol grafting, and net surface charge of iron oxide nanoparticles determine their interaction and toxicity in Caenorhabditis elegans 142060 EN Yajuan Zou Graduate School of Natural Science and Technology, Okayama University Yutaka Shikano Institute of Systems and Information Engineering, University of Tsukuba Yuta Nishina Graduate School of Natural Science and Technology, Okayama University Naoki Komatsu Graduate School of Human and Environmental Studies, Kyoto University Eriko Kage-Nakadai Department of Nutrition, Graduate School of Human Life and Ecology, Osaka Metropolitan University Masazumi Fujiwara Graduate School of Natural Science and Technology, Okayama University 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. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1359-7345 59 17 2023 Non-enzymatic detection of glucose levels in human blood plasma by a graphene oxide-modified organic transistor sensor 2425 2428 EN Haonan Fan Institute of Industrial Science, The University of Tokyo Yui Sasaki Institute of Industrial Science, The University of Tokyo Qi Zhou Institute of Industrial Science, The University of Tokyo Wei Tang Institute of Industrial Science, The University of Tokyo Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Tsuyoshi Minami Institute of Industrial Science, The University of Tokyo We herein report an organic transistor functionalized with a phenylboronic acid derivative and graphene oxide for the quantification of plasma glucose levels, which has been achieved by the minimization of interferent effects derived from physical protein adsorption on the detection electrode. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 2694-2453 3 5 2023 Highly Stretchable Stress-Strain Sensor from Elastomer Nanocomposites with Movable Cross-links and Ketjenblack 394 405 EN Ryohei Ikura Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University Kota Kajimoto Department of Macromolecular Science, Graduate School of Science, Osaka University Junsu Park Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University Shunsuke Murayama Graduate School of Organic Materials Engineering, Yamagata University Yusei Fujiwara Department of Mechanical Engineering, Osaka Institute of Technology Motofumi Osaki Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University Tomohiro Suzuki Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. Hidenori Shirakawa Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. Yujiro Kitamura Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. Hiroaki Takahashi Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. Yasumasa Ohashi Kanagawa Technical Center, Yushiro Chemical Industry Co., Ltd. Seiji Obata Research Core for Interdisciplinary Sciences, Okayama University Akira Harada SANKEN (The Institute of Scientific and Industrial Research), Osaka University Yuka Ikemoto Japan Synchrotron Radiation Research Institute Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Yasutomo Uetsuji Department of Mechanical Engineering, Osaka Institute of Technology Go Matsuba Graduate School of Organic Materials Engineering, Yamagata University Yoshinori Takashima Department of Macromolecular Science, Graduate School of Science and Forefront Research Center for Fundamental Sciences, Osaka University Practical applications like very thin stress-strain sensors require high strength, stretchability, and conductivity, simultaneously. One of the approaches is improving the toughness of the stress-strain sensing materials. Polymeric materials with movable cross-links in which the polymer chain penetrates the cavity of cyclodextrin (CD) demonstrate enhanced strength and stretchability, simultaneously. We designed two approaches that utilize elastomer nanocomposites with movable cross-links and carbon filler (ketjenblack, KB). One approach is mixing SC (a single movable cross-network material), a linear polymer (poly(ethyl acrylate), PEA), and KB to obtain their composite. The electrical resistance increases proportionally with tensile strain, leading to the application of this composite as a stress- strain sensor. The responses of this material are stable for over 100 loading and unloading cycles. The other approach is a composite made with KB and a movable cross-network elastomer for knitting dissimilar polymers (KP), where movable cross-links connect the CD-modified polystyrene (PSCD) and PEA. The obtained composite acts as a highly sensitive stress-strain sensor that exhibits an exponential increase in resistance with increasing tensile strain due to the polymer dethreading from the CD rings. The designed preparations of highly repeatable or highly responsive stress-strain sensors with good mechanical properties can help broaden their application in electrical devices. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2516-0230 4 10 2022 Synergic effect of graphene oxide and boron nitride on the mechanical properties of polyimide composite films 2339 2345 EN Yi Kai Cheng Graduate School of Natural Science and Technology, Okayama University Benoît Denis Louis Campéon Research Core for Interdisciplinary Sciences, Okayama University Seiji Obata Research Core for Interdisciplinary Sciences, Okayama University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University The addition of two-dimensional (2D) materials into polymers can improve their mechanical properties. In particular, graphene oxide (GO) and hexagonal boron nitride (h-BN) are expected to be potential nanoplatelet additives for polymers. Interactions between such nanoplatelets and polymers are effective in improving the above properties. However, no report has investigated the effect of using two types of nanoplatelets that have good interaction with polymers. In this study, we fabricated polyimide (PI) films that contain two types of nanoplatelets, amine-functionalized h-BN (BNNH2) and GO. We have elucidated that the critical ratio and the content of BNNH2 and GO within PI govern the films' mechanical properties. When the BNNH2/GO weight ratio was 52 : 1 and their content was 1 wt% in the PI film, the tensile modulus and tensile strength were increased by 155.2 MPa and 4.2 GPa compared with the pristine PI film. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 1477-9226 51 5 2022 Grafting redox-active molecules on graphene oxide through a diamine linker: length optimization for electron transfer 1874 1878 EN Rizwan Khan Graduate school of natural science and technology, Okayama University Yuta Nishina Graduate school of natural science and technology, Okayama University A redox-active molecule is grafted on graphene oxide (GO) via successive reactions. In the first step, GO is modified with diamine, which acts as a linker for the redox-active molecule. In the second step, the redox-active molecule is attached to the amino group of the linker by amide bond formation. Through these processes GO is partially reduced, enhancing its electrochemical properties. The structure of the functionalized GO is characterized by XPS, TGA, FTIR, and CV, and applied for electrodes in supercapacitors (SCs). The distance and direction of the redox-active molecule on the electrode affect the SC performance; ethylene diamine is the most promising linker to efficiently transfer electrons from the redox-active molecule to the electrode surface. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0169-4332 573 30 2022 Uniform coating of magnesium oxide crystal with reduced graphene oxide achieves moisture barrier performance 151483 EN Akinori Saito Tateho chemical industries co. ltd Seiji Obata Research Core for Interdisciplinary Sciences, Okayama University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Magnesium oxide (MgO) has high thermal conductivity while keeping insulation; thus, MgO is attractive material as a filler for thermosetting or thermoplastic resins. However, MgO readily hydrates with water or moisture. Thus, the surface of MgO is coated with organic or inorganic substances. <br> We focused on graphene oxide (GO) as a surface coating agent. It has a 2-dimensional thin sheet structure, oxygen functional groups on the surface, and negative zeta-potential. Typically, GO has been used as a support material for metal nanoparticles. In this research, GO was coated on MgO micro-crystal surface to improve the surface character of MgO. The negatively charged GO and the positively charged MgO were combined with strong interaction. 0.5wt% GO coated MgO showed excellent moisture resistance compared to organic substances coating. Coating of MgO with GO or rGO is effective to overcome the weaknesses of MgO. Due to the hydrophilicity and high thermal conductivity of rGO, MgO/rGO composite can be a filler for high moisture resistance and thermal conductivity. No potential conflict of interest relevant to this article was reported.

IOP Publishing Ltd Acta Medica Okayama 2515-7655 3 3 2021 Simulating the redox potentials of unexplored phenazine derivatives as electron mediators for biofuel cells 034008 EN Ryo Nakagawa Graduate School of Natural Science and Technology, Okayama University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University In this research, we aimed to establish a guideline for designing electron mediators suitable for biofuel cells. A redox potential simulator was fabricated by combining density functional theory calculation and experiment, allowing us to select molecules with appropriate redox potentials efficiently. Previously, mediators have been developed depending on the trials and errors; thus, our strategy will speed up the development of biofuel cells with outstanding performances. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 2516-0230 2 10 2020 Bottom-up synthesis of nitrogen-doped nanocarbons by a combination of metal catalysis and a solution plasma process 4417 4420 EN Yang Zhou Graduate School of Natural Science and Technology, Okayama University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University We aimed to develop the bottom-up synthesis of nanocarbons with specific functions from molecules without any leaving group, halogen atom and boronic acid, by employing a metal catalyst under solution plasma irradiation. Pyridine was used as a source of carbon. In the presence of a Pd catalyst, the plasma treatment enabled the synthesis of N-doped carbons with a pyridinic configuration, which worked as an active catalytic site for the oxygen reduction reaction. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0013-4686 363 2020 Sophisticated rGO synthesis and pre-lithiation unlocking full-cell lithium-ion battery high-rate performances 137257 EN Benoît Denis Louis Campéon Graduate School of Natural Science and Technology, Okayama University Yumi Yoshikawa Graduate School of Natural Science and Technology, Okayama University Takashi Teranishi Graduate School of Natural Science and Technology, Okayama University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University For the application to portable devices and storage of renewable energies, high-performance lithium-ion batteries are in great demand. To this end, the development of high-performance electrode materials has been actively investigated. However, even if new materials exhibit high performance in a simple evaluation, namely half-cell tests, it is often impossible to obtain satisfactory performance with an actual battery (full cell). In this study, the structure of graphene analogs is modified in various ways to change crystallinity, disorder, oxygen content, electrical conductivity, and specific surface area. These graphene analogs are evaluated as negative electrodes for lithium-ion batteries, and we found reduced graphene oxide prepared by combination of chemical reduction and thermal treatment was the optimum. In addition, a full cell is fabricated by combining it with LiCoO2 modified with BaTiO3, which is applicable to high-speed charge–discharge cathode material developed in our previous research. In general, pre-lithiation is performed for the anode when assembling full cells. In this study, we optimized a "direct pre-lithiation" method in which the electrode and lithium foil were in direct contact before assembling a full cell, and created a lithium-ion battery with an output of 293 Wh kg|1 at 8,658 W kg|1. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 2040-3364 12 42 2020 Iron nanoparticle templates for constructing 3D graphene framework with enhanced performance in sodium-ion batteries 21780 21787 EN Benoît D. L. Campéon Graduate School of Natural Science and Technology, Okayama University Chen Wang Research Core for Interdisciplinary Sciences, Okayama University Yuta Nishina Graduate School of Natural Science and Technology, Okayama University This study examines the synthesis and electrochemical performance of three-dimensional graphene for Li-ion batteries and Na-ion batteries. The in situ formation of iron hydroxide nanoparticles (Fe(OH)x NPs) of various weights on the surface of graphene oxide, followed by thermal treatment at elevated temperature and washing using hydrochloric acid, furnished 3D graphene. The characterization studies confirmed the prevention of graphene layer stacking by over 90% compared with thermal treatment without Fe(OH)x. The electrochemical performance of the 3D graphene was evaluated as a counter electrode for lithium metal and sodium metal in a half-cell configuration. This material showed good performances with a charging capacity of 507 mA h g|1 at 372 mA g|1 in Li-ion batteries and 252 mA h g|1 at 100 mA g|1 in Na-ion batteries, which is 1.4 and 1.9 times higher, respectively, than the graphene prepared without Fe(OH)x templates. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 2041-6539 11 23 2020 Carbon-rich materials with three-dimensional ordering at the angstrom level 5866 5873 EN Shixin Fa Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Masanori Yamamoto Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Hirotomo Nishihara Institute of Multidisciplinary Research for Advanced Materials, Tohoku University Ryota Sakamoto Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University Kazuhide Kamiya Graduate School of Engineering Science, Osaka University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Tomoki Ogoshi Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University Carbon-rich materials, which contain over 90% carbon, have been mainly synthesized by the carbonization of organic compounds. However, in many cases, their original molecular and ordered structures are decomposed by the carbonization process, which results in a failure to retain their original three-dimensional (3D) ordering at the angstrom level. Recently, we successfully produced carbon-rich materials that are able to retain their 3D ordering at the angstrom level even after the calcination of organic porous pillar[6]arene supramolecular assemblies and cyclic porphyrin dimer assemblies. Other new pathways to prepare carbon-rich materials with 3D ordering at the angstrom level are the controlled polymerization of designed monomers and redox reaction of graph. Electrocatalytic application using these materials is described. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-9717 8 2 2020 Structural Optimization of Alkylbenzenes as Graphene Dispersants 238 EN Shimpei Takeda Graduate School of Natural Science & Technology, Okayama University Yuta Nishina Graduate School of Natural Science & Technology, Okayama University Among the several methods of producing graphene, the liquid-phase exfoliation of graphite is attractive because of a simple and easy procedure, being expected for mass production. The dispersibility of graphene can be improved by adding a dispersant molecule that interacts with graphene, but the appropriate molecular design has not been proposed. In this study, we focused on aromatic compounds with alkyl chains as dispersing agents. We synthesized a series of alkyl aromatic compounds and evaluated their performance as a dispersant for graphene. The results suggest that the alkyl chain length and solubility in the solvent play a vital role in graphene dispersion. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 13882481 104 2019 Bipolar anodic electrochemical exfoliation of graphite powders 106475 EN Hideki Hashimoto Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University Yusuke Muramatsu Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Hidetaka Asoh Department of Applied Chemistry, School of Advanced Engineering, Kogakuin University The electrochemical exfoliation of graphite has attracted considerable attention as a method for large-scale, rapid production of graphene and graphene oxide (GO). As exfoliation typically requires direct electrical contact, and is limited by the shape and/or size of the starting graphite, treatment of small graphite particles and powders, the typical form available commercially, is extremely difficult. In this study, GO nanosheets were successfully prepared from small graphite particles and powders by a bipolar electrochemical process. Graphite samples were placed between two platinum feeder electrodes, and a constant current was applied between the feeder electrodes using dilute sulfuric acid as the electrolyte. Optical microscopy, atomic force microscopy, X-ray diffractometry, Raman spectroscopy, and X-ray photoelectron spectroscopy were employed to examine the samples obtained after electrolysis. The results obtained from these analyses confirmed that anodic electrochemical exfoliation occurs in the graphite samples, and the exfoliated samples are basically highly crystalline GO nanosheets with a low degree of oxidation (C/O = 3.6–5.3). This simple electrochemical method is extremely useful for preparing large amounts of graphene and GO from small particles of graphite. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 15205002 29 5 2017 Real-Time, in Situ Monitoring of the Oxidation of Graphite: Lessons Learned 2150 2156 EN Naoki Morimoto Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama University Hideyuki Suzuki Research Core for Interdisciplinary Sciences, Okayama University Yasuo Takeuchi Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama Universit Shogo Kawaguchi Japan Synchrotron Radiation Research Institute (JASRI), SPring-8 Masahiro Kunisu Toray Research Center, Inc., Surface Science Laboratories Christopher W. Bielawski Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS) Yuta Nishina Research Core for Interdisciplinary Sciences, Okayama University Graphite oxide (GO) and its constituent layers (i.e., graphene oxide) display a broad range of functional groups and, as such, have attracted significant attention for use in numerous applications. GO is commonly prepared using the gHummers methodh or a variant thereof in which graphite is treated with KMnO4 and various additives in H2SO4. Despite its omnipresence, the underlying chemistry of such oxidation reactions is not well understood and typically affords results that are irreproducible and, in some cases, unsafe. To overcome these limitations, the oxidation of graphite under Hummers-type conditions was monitored over time using in situ X-ray diffraction and in situ X-ray absorption near edge structure analyses with synchrotron radiation. In conjunction with other atomic absorption spectroscopy, UV–vis spectroscopy and elemental analysis measurements, the underlying mechanism of the oxidation reaction was elucidated, and the reaction conditions were optimized. Ultimately, the methodology for reproducibly preparing GO on large scales using only graphite, H2SO4, and KMnO4 was developed and successfully adapted for use in continuous flow systems. No potential conflict of interest relevant to this article was reported.