76
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Ounkaew A, Kasemsiri P, Jetsrisuparb K, Uyama H, Hsu YI, Boonmars T, Artchayasawat A, Knijnenburg JTN, Chindaprasirt P. Synthesis of nanocomposite hydrogel based carboxymethyl starch/polyvinyl alcohol/nanosilver for biomedical materials. Carbohydr Polym 2020; 248:116767. [PMID: 32919563 DOI: 10.1016/j.carbpol.2020.116767] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/09/2020] [Accepted: 07/11/2020] [Indexed: 12/14/2022]
Abstract
Treatment of infections using wound dressing integrated with multiple functions such as antibacterial activity, non-toxicity, and good mechanical properties has attracted much attention. In this study, carboxymethyl starch/polyvinyl alcohol/citric acid (CMS/PVA/CA) hydrogels containing silver nanoparticles (AgNPs) were prepared. The CMS, PVA and CA were used as polymer matrix and bio-based reducing agents for green synthesis of AgNPs. Silver nitrate (AgNO3) concentrations of 50, 100, and 150 mM were used to obtain nanocomposite hydrogels containing different AgNPs concentrations (AgNPs-50, AgNPs-100 and AgNPs-150, respectively). The minimum inhibitory concentration against E. coli and S. aureus was observed in CMS/PVA/CA hydrogels containing AgNPs-50. Uniform dispersion of AgNPs-100 in the hydrogel provided the highest storage modulus at 56.4 kPa. AgNPs-loaded hydrogels showed low toxicity to human fibroblast cells indicating good biocompatibility. Incorporation of AgNPs demonstrated an enhancement in antibacterial properties and overall mechanical properties, which makes these nanocomposite hydrogels attractive as novel wound dressing materials.
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77
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Cao Y, Han W, Pu Z, Wang X, Wang B, Liu C, Uyama H, Shen C. Fabrication of hierarchically porous superhydrophilic polycaprolactone monolith based on nonsolvent-thermally induced phase separation. RSC Adv 2020; 10:26319-26325. [PMID: 35519741 PMCID: PMC9055430 DOI: 10.1039/d0ra04687f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/08/2020] [Indexed: 12/01/2022] Open
Abstract
Monoliths with a continuous porous structure are of great interest due to high transfer efficiency and large surface area in environmental and tissue engineering fields. This study demonstrated a facile method to prepare PCL monoliths with hierarchically porous structure by nonsolvent-thermally induced phase separation. A suitable mixed solvent mixture using ethanol as nonsolvent reduced the amount of dioxane and provided PCL monoliths with three levels of structures. The monolith structure was easily controlled by changing the fabrication parameters, such as the nonsolvent, the temperature of phase separation, the concentration of the PCL. Finally, the superhydrophilic monolith was easily obtained by polydopamine surface modification. The easy way of fabrication of a hierarchically porous PCL monolith with superhydrophilicity will find applications such as in tissue engineering and purification.
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78
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Tamiya T, Hsu YI, Asoh TA, Uyama H. Improvement of Interfacial Adhesion between Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Silica Particles. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c02284] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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79
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Lyu Y, Asoh TA, Uyama H. Hierarchical silica monolith prepared using cellulose monolith as template. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109164] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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80
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Sugawara A, Asoh TA, Takashima Y, Harada A, Uyama H. Composite hydrogels reinforced by cellulose-based supramolecular filler. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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81
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Jia Y, Asoh TA, Hsu YI, Uyama H. Wet strength improvement of starch-based blend films by formation of acetal/hemiacetal bonding. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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82
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Soni R, Asoh TA, Hsu YI, Shimamura M, Uyama H. Effect of starch retrogradation on wet strength and durability of cellulose nanofiber reinforced starch film. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109165] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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83
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Qian C, Higashigaki T, Asoh TA, Uyama H. Anisotropic Conductive Hydrogels with High Water Content. ACS APPLIED MATERIALS & INTERFACES 2020; 12:27518-27525. [PMID: 32449346 DOI: 10.1021/acsami.0c06853] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
High water content is hard to be achieved in conductive hydrogels because a mass of conductive constituent is needed to form an internal conductive pathway. Here, we developed anisotropic electrically conductive hydrogels with high water content based on bacterial cellulose (BC). Polystyrene sulfonate (PSS) was grafted to the acryloyl chloride-modified BC to provide a template for the subsequent synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT). The BC-g-PSS/PEDOT hydrogels obtained were electrically conductive owing to the immobilization of PEDOT on the surface of cellulose nanofibers. The hydrogels exhibited an electrical conductivity of 0.24 S cm-1. Further, they demonstrated suppleness in compression (compiled to external compression stress >2.8 MPa and recoverable), inherent high water content (∼95.0 wt %), and anisotropy (anisotropic index of 4.1 in conductivity) from BC. The incorporation of a thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) hydrogel into the BC-g-PSS/PEDOT hydrogel demonstrated a uniaxial thermoresponsive actuation with resistance change. The expected size and resistance change were only observed in the direction vertical to the cellulose nanofiber layers. These hydrogels could accommodate further developments in novel tissue engineering scaffolds, implantable biosensors, and smart soft electronic devices.
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84
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Inoue S, Yamaguchi S, Uyama H, Yamashiro T, Imazato S. Influence of constant strain on the elasticity of thermoplastic orthodontic materials. Dent Mater J 2020; 39:415-421. [PMID: 31827059 DOI: 10.4012/dmj.2019-104] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to identify a physical property suitable for evaluating the orthodontic force by analyzing the physical properties of thermoplastic materials. Four thermoplastic materials were used: Essix A+® Plastic (EA), DURAN® (DU), Erkodur (ER), and Essix C+® Plastic (EC). Finite element analysis (FEA), a water absorption test, constant strain loading test, X-ray diffraction (XRD) and Fourier transformation infrared spectroscopy analysis were conducted. FEA found a significant correlation between the elastic modulus and the orthodontic force. The water absorption of EC was significantly smaller than the other materials. EC showed no elastic modulus change. The XRD pattern indicated that EC was a crystalline polymer. FEA of thermoplastics showed that the elastic modulus is suitable for the evaluation of orthodontic force. The crystalline thermoplastic EC demonstrated a stable elastic modulus even under strain in a wet environment, suggesting the advantage of its use as an orthodontic aligner material.
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85
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Soni R, Asoh TA, Uyama H. Cellulose nanofiber reinforced starch membrane with high mechanical strength and durability in water. Carbohydr Polym 2020; 238:116203. [DOI: 10.1016/j.carbpol.2020.116203] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 01/06/2023]
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86
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Jia Y, Chen J, Asahara H, Hsu YI, Asoh TA, Uyama H. Photooxidation of the ABS resin surface for electroless metal plating. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122592] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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87
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Asoh TA, Nakamura M, Shoji T, Tsuboi Y, Uyama H. Electrophoretic Adhesion of Conductive Hydrogels. Macromol Rapid Commun 2020; 41:e2000169. [PMID: 32400894 DOI: 10.1002/marc.202000169] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/29/2022]
Abstract
For the development of next-generation wearable and implantable devices that connect the human body and machines, the adhesion of a conductive hydrogel is required. In this study, a conductive hydrogel is adhered using an electrophoretic approach through polyion complex formation at the interface of the hydrogels. Cationic and anionic conductive hydrogels adhere to anionic and cationic hydrogels, respectively. Moreover, the cationic and anionic conductive hydrogels adhere strongly to each other and the adhered conductive hydrogels exhibit conductivity. De-adhesion is possible by adding a salt and re-adhesion is demonstrated under aqueous conditions. It is believed that this innovative adhesion strategy for conductive hydrogels will be a fundamental technology for the connecting "soft" people and "hard" machines.
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88
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Tamiya T, Cui X, Hsu YI, Kanno T, Asoh TA, Uyama H. Enhancement of interfacial adhesion in immiscible polymer blend by using a graft copolymer synthesized from propargyl-terminated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2020.109662] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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89
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Kato M, Kashihara Y, Asoh TA, Uyama H. Geometry Control of Wrinkle Structures Aligned on Hydrogel Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1467-1473. [PMID: 31999120 DOI: 10.1021/acs.langmuir.9b03967] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface geometries in nature such as wrinkle structures have various functions. Attention has been paid to the fabrication method of the geometry and geometry control by external stimuli. This is because surface geometries as an active interface are able to contribute to the control of interactions with the external environment. In this study, aligned wrinkles were fabricated on the surface of stretched hydrogels in aqueous conditions by the electrophoretic formation of a polyion complex layer. The geometry of wrinkles was controlled by the stretching ratio and Young's modulus of hydrogels, and hierarchical wrinkle structures were fabricated after unloading the stretched hydrogels. Therefore, it can be a new wrinkle-formation method capable of transferring the initial elastic anisotropy of the substrate material to the wrinkle structure. Creation of thermoresponsive wrinkles that can transform their geometrical configuration reversibly was achieved by fabrication of aligned wrinkles on the surface of thermoresponsive hydrogels.
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90
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Yang Z, Asoh TA, Uyama H. A cellulose monolith supported metal/organic framework as a hierarchical porous material for a flow reaction. Chem Commun (Camb) 2020; 56:411-414. [DOI: 10.1039/c9cc08232h] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel cellulose monolith supported ZIF-8 metal organic framework as a hierarchical porous material was designed by using a highly effective pump injection method, which is used for a flow-based reaction.
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91
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Qian C, Asoh TA, Uyama H. Osmotic squat actuation in stiffness adjustable bacterial cellulose composite hydrogels. J Mater Chem B 2020; 8:2400-2409. [DOI: 10.1039/c9tb02880c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stimuli-responsive stiffness change and squat actuation were realized in bacterial cellulose hydrogels by utilizing internal osmotic pressure changes.
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92
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Maruyama J, Shinagawa T, Watanabe M, Kashiwagi Y, Maruyama S, Nagaoka T, Matsuda W, Tsutsui Y, Seki S, Uyama H. Helical Pore Alignment on Cylindrical Carbon. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905916. [PMID: 31797554 DOI: 10.1002/smll.201905916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 10/30/2019] [Indexed: 06/10/2023]
Abstract
Interest in chiral substances has mainly focused on the substances themselves, but not on the accompanying space, especially regarding the pore alignment. As a method to form both the chiral substance and the accompanying space, cylindrical self-assembly of uniform polystyrene nanoparticles with fructose is carried out in the presence of both carbon and sodium alginate, which is followed by heat treatment in an inert atmosphere. The carbonization generates fructose-derived honeycomb-like carbon walls with helically aligned nanopores left after the polystyrene decomposition. The diffuse reflectance circular dichroism measurements give peaks with opposite signs for the d- and l-fructose-derived cylindrical carbons. Circularly polarized light sensitivity in transient photoconductivity is confirmed apparently in the carbon-based helical structures. This sensitivity as well as straightforward formation of composites with another component to give helicity shows potential applications of the helically aligned pores.
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93
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Wang G, Niu J, Asoh TA, Uyama H. Fabrication of compressible polyolefin monoliths and their applications. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2019.09.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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94
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Cui X, Honda T, Asoh TA, Uyama H. Cellulose modified by citric acid reinforced polypropylene resin as fillers. Carbohydr Polym 2019; 230:115662. [PMID: 31887947 DOI: 10.1016/j.carbpol.2019.115662] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/18/2019] [Accepted: 11/22/2019] [Indexed: 11/20/2022]
Abstract
The greatest challenge hindering the use of cellulose as a reinforcing filler in polymeric composites is its poor compatibility due to the inherent hydrophilicity of cellulose and the hydrophobic nature of polymeric matrices. To solve this issue, we demonstrate an effective water-based method to render the cellulose surface with high carboxyl content through the esterification of hydroxyl groups with citric acid in a solid phase reaction without the use of noxious solvents. The modified cellulose was then further hydrophobized by grafting magnesium stearate to the surface. Consequently, the flexural properties of PP composites reinforced by the hydrophobized cellulose fillers were greatly improved compared to those of composites containing hydrophilic cellulose and pure PP resin. The surface modification conditions and filler proportions in composites were optimized. Because of the innocuity and cost-efficiency of citric acid, we believe that citric acid-modified cellulose has immense potential as a sustainable and cost-effective reinforcing filler.
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95
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Kato M, Asoh T, Uyama H. Hydrogel Adhesion by Wrinkling Films. Macromol Rapid Commun 2019; 40:e1900434. [DOI: 10.1002/marc.201900434] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/21/2019] [Indexed: 01/13/2023]
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96
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Shu Y, Bai Q, Fu G, Xiong Q, Li C, Ding H, Shen Y, Uyama H. Hierarchical porous carbons from polysaccharides carboxymethyl cellulose, bacterial cellulose, and citric acid for supercapacitor. Carbohydr Polym 2019; 227:115346. [PMID: 31590873 DOI: 10.1016/j.carbpol.2019.115346] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/11/2019] [Accepted: 09/18/2019] [Indexed: 01/07/2023]
Abstract
This study reports excellent supercapacitor performance of hierarchical composite porous carbon (HPC) materials successfully fabricated by one-step carbonization and activation process derived from polysaccharides carboxymethyl cellulose, bacterial cellulose, and citric acid. The resultant HPC displayed unique porous nanosheet morphology with high specific surface area (2490 m2 g-1) and rich oxygen content (7.3%). The developed structures with macropores, mesopore walls, micropores, and high oxygen content led to excellent electrochemical performance for electrode of electric double-layer capacitors (EDLCs). In a three-electrode system, the HPC electrode showed a high specific capacitance of 350 F g-1, good rate performance, and excellent cycling stability. The energy density of supercapacitor based on HPC was comparable to or higher than that of commercially supercapacitors. More importantly, two series-wound devices were easy to light light-emitting diode (LED, 3.0 V). These results suggest that the current material is a promising candidate for low-cost and eco-friendly energy storage devices.
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97
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Yang Z, Asoh TA, Uyama H. Removal of Cationic or Anionic Dyes from Water Using Ion Exchange Cellulose Monoliths as Adsorbents. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190111] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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98
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Harada N, Nakamura JI, Uyama H. Preparation of Macroporous Cellulose Beads through a Single-Step Non-Solvent Induced Phase Separation Method from a Cellulose Acetate Solution. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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99
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Park SJ, Uyama H, Kwak MS, Sung MH. Comparison of the Stability of Poly-γ-Glutamate Hydrogels Prepared by UV and γ-Ray Irradiation. J Microbiol Biotechnol 2019; 29:1078-1082. [PMID: 31280528 DOI: 10.4014/jmb.1812.12018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Poly-γ-glutamate (γ-PGA) has various applications due to its desirable characteristics in terms of safety and biodegradability. Previous studies have been conducted on γ-PGA hydrogels produced by γ-ray irradiation, but these hydrogels have proved unstable in solutions. This study was conducted to enable the γ-PGA hydrogel to maintain a stable form in solutions. The γ-PGA mixture for UV-irradiation was prepared with a cross-linker (N,N,N-trimethyl-3-[(2- methylacryloyl)amino]propan-1-aminium). Both γ-PGA hydrogels' characteristics, including stability in solutions, were examined. The UV-irradiated γ-PGA hydrogel maintained a stable form during the nine weeks of the study, but the γ-ray irradiated hydrogel dissolved after one week.
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100
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Tamano K, Nakasha K, Iwamoto M, Numata M, Suzuki T, Uyama H, Fukuhara G. Chiroptical properties of reporter-modified or reporter-complexed highly 1,6-glucose-branched β-1,3-glucan. Polym J 2019. [DOI: 10.1038/s41428-019-0222-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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