start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=2023217 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Preparation of crystalline polyimide nanofibers via solution crystallization en-subtitle= kn-subtitle= en-abstract= kn-abstract=Two crystalline polyimide nanofibers (PINFs) with different morphologies were prepared. The crystalline unit cells of the aromatic PI crystals and the crystal morphologies of the fabricated PINFs were examined. PINF-I (lengths?=?305?}?152?nm and diameters?=?12?}?2?nm) was crystallized from crystalline PI dissolved in a concentrated sulfuric acid solution. The resulting PINF-I was isolated from this solution, and it did not aggregate in water. PINF-II with diameters of 105?}?99?nm was prepared by dispersing PINF-I in a mixed water and t-butanol (TBA) solution (water:TBA?=?4:1), followed by freeze-drying. Then, the PINF-II was heated to enhance its crystallinity. X-ray diffraction and transmission electron microscopy studies of the heat-treated PINF-II revealed a PI crystalline unit cell [orthorhombic, a?=?1.21?nm, b?=?0.88?nm, and c?=?2.23?nm (molecular chain axis direction)]. The crystal structure of the heat-treated PINF-II suggested that highly crystalline PINFs were fabricated in which the PI molecular chains were oriented along the direction of the fiber lengths. en-copyright= kn-copyright= en-aut-name=KumanoShota en-aut-sei=Kumano en-aut-mei=Shota kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakakiTomoyasu en-aut-sei=Takaki en-aut-mei=Tomoyasu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=33 cd-vols= no-issue=8 article-no= start-page=2511 end-page=2518 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220426 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Preparation of cellulose nanocrystals coated with polymer crystals and their application in composite films en-subtitle= kn-subtitle= en-abstract= kn-abstract=Increasing the dispersibility of cellulose nanocrystals (CNCs) as a reinforcing material is highly desirable to obtain composites with enhanced mechanical properties. To this aim, nanocomposite fibers (NCF(CNC/polymer)) were fabricated by coating CNCs with polymer crystals. Poly(vinyl alcohol) (PVA) and poly(vinyl alcohol-co-ethylene) (EVOH) were crystallized from a dilute solution in the presence of CNCs, which acted as nucleating agents for polymer crystal growth on the CNC surface. NCF consisting of CNCs coated with PVA crystals (NCF(CNC/PVA)) and CNCs coated with EVOH crystals (NCF(CNC/EVOH)) were successfully obtained. Both NCF(CNC/polymer) showed good dispersibility in water, even after drying, and were used to prepare composite films with improved mechanical properties. The reinforcement effect of NCF(CNC/PVA) was greater than that of pure CNCs and NCF(CNC/EVOH). The PVA composite films exhibited optical transmittance above 99% compared with additive-free PVA films. No agglomerates appeared even under the optical microscopic observation of the PVA composite film, and NCF(CNC/PVA) dispersibility was extremely good. NCF(CNC/PVA)-added PVA composite films exhibited increased glass transition temperature compared with additive-free PVA films, and the crystallinity of the PVA film increased. The highly dispersed CNCs in the PVA matrix and the increase in the glass transition temperature and crystallinity caused an increase in the mechanical modulus of the PVA composite film at low NCF(CNC/PVA) content. Furthermore, the effect of the morphologies of cellulose nanofibers and CNCs on the mechanical properties of the composite films prepared using the respective NCFs was investigated. en-copyright= kn-copyright= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NishiokaRyohei en-aut-sei=Nishioka en-aut-mei=Ryohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YanaiRisa en-aut-sei=Yanai en-aut-mei=Risa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=cellulose nanocrystals kn-keyword=cellulose nanocrystals en-keyword=composite kn-keyword=composite en-keyword=dispersibility kn-keyword=dispersibility en-keyword=mechanical properties kn-keyword=mechanical properties en-keyword=surface treatment kn-keyword=surface treatment END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=1 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=202199 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Preparation of highly porous heat]resistant polybenzoxazole network films and their electrical conductivities en-subtitle= kn-subtitle= en-abstract= kn-abstract=Highly porous rigid polybenzoxazole (PBO) network films were prepared using a precursor-mediated fabrication method. The obtained PBO network films possessed high porosities of similar to 40%, as calculated from their apparent densities. In addition, the 5%-weight-loss temperatures of the films were >= 570 degrees C under nitrogen atmosphere, demonstrating an excellent thermal stability. The electrical conductivities of the obtained PBO network films and phosphoric-acid-doped PBO network films were also evaluated. In addition, PBO network films containing pyridine rings were prepared and subjected to phosphoric acid doping. The resultant films were found to exhibit the highest conductivities of the films considered in this study owing to proton conduction both between phosphate groups and between the pyridine rings. The highest conductivity was found for a film prepared from a phosphoric-acid-doped PBO network containing pyridine rings, that is, 2.09 x 10(-1) S/cm at 150 degrees C, which was higher than that of Nafion (TM). Therefore, these films can be used at higher temperatures than that of Nafion (TM). en-copyright= kn-copyright= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OnishiYukihisa en-aut-sei=Onishi en-aut-mei=Yukihisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=GotoAtsu en-aut-sei=Goto en-aut-mei=Atsu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology Okayama University kn-affil= en-keyword=rigid polymer network kn-keyword=rigid polymer network en-keyword=heat resistance kn-keyword=heat resistance en-keyword=proton kn-keyword=proton en-keyword=phosphoric acid kn-keyword=phosphoric acid en-keyword=conductivity kn-keyword=conductivity END start-ver=1.4 cd-journal=joma no-vol=307 cd-vols= no-issue= article-no= start-page=130978 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20211001 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Clarification of degradation mechanism on retinal prosthesis using photoelectric dyes coupled to polyethylene film by mass spectrometry en-subtitle= kn-subtitle= en-abstract= kn-abstract=Photoelectric dyes have stimulated retinal neurons by absorbing light and generating an electric potential. Therefore, a photoelectric dye was used to develop a retinal prosthesis to restore vision loss due to retinitis pigmentosa. The retinal prosthesis, referred to as a dye-coupled film, was prepared by chemically coupling the dyes to a polyethylene film surface through amide bonds. However, the coupled dyes decreased during an implantation test in a monkey eye. This study clarifies the degradation mechanism of the dye-coupled film. Since the dyes were selectively coupled to the film surface, it is difficult to detect the eliminated dyes in a solution. Therefore, a model compound that mimicked the chemical structure of the dye-coupled film by converting the carboxylic acid of dye to the amide bond is used. It was found that the elimination of the side chain, including the amide bond, occurred before the degradation of the conjugated structure according to mass spectrometry of the model compound. The degradation mechanism of the dye-coupled film was predicted based on that of the model compound. It was concluded that chemical bonds between the dye and the film surface were preferentially decomposed, leading to the detachment of the dyes from the film surface. en-copyright= kn-copyright= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MitsuiMayu en-aut-sei=Mitsui en-aut-mei=Mayu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Degradation kn-keyword=Degradation en-keyword=Photoelectric dye kn-keyword=Photoelectric dye en-keyword=Benzothiazole kn-keyword=Benzothiazole en-keyword=Mass spectrometry kn-keyword=Mass spectrometry en-keyword=Retinal prosthesis kn-keyword=Retinal prosthesis END start-ver=1.4 cd-journal=joma no-vol=11 cd-vols= no-issue=6 article-no= start-page=591 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=2021621 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Photoelectric Dye, NK-5962, as a Potential Drug for Preventing Retinal Neurons from Apoptosis: Pharmacokinetic Studies Based on Review of the Evidence en-subtitle= kn-subtitle= en-abstract= kn-abstract=NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 ƒÊM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 ƒÊM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa. en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=LiuShihui en-aut-sei=Liu en-aut-mei=Shihui kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OnoueSatomi en-aut-sei=Onoue en-aut-mei=Satomi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NakagawaShinsaku en-aut-sei=Nakagawa en-aut-mei=Shinsaku kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=IshiiMayumi en-aut-sei=Ishii en-aut-mei=Mayumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KanamitsuKayoko en-aut-sei=Kanamitsu en-aut-mei=Kayoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=Department of Ophthalmology, Okayama University Hospital kn-affil= affil-num=2 en-affil=Okayama University Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=3 en-affil=Polymer Materials Science, Okayama University Graduate School of Natural Science and Technology kn-affil= affil-num=4 en-affil=Laboratory of Biopharmacy, School of Pharmaceutical Sciences, University of Shizuoka kn-affil= affil-num=5 en-affil=Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Osaka University kn-affil= affil-num=6 en-affil=Drug Discovery Initiative, The University of Tokyo kn-affil= affil-num=7 en-affil=Drug Discovery Initiative, The University of Tokyo kn-affil= en-keyword=NK-5962 kn-keyword=NK-5962 en-keyword=photoelectric dye kn-keyword=photoelectric dye en-keyword=apoptosis kn-keyword=apoptosis en-keyword=retinal neuron kn-keyword=retinal neuron en-keyword=neuroprotection kn-keyword=neuroprotection en-keyword=pharmacokinetics kn-keyword=pharmacokinetics en-keyword=ADME kn-keyword=ADME en-keyword=phototoxic/photosensitive assay kn-keyword=phototoxic/photosensitive assay en-keyword=reactive oxygen species assay kn-keyword=reactive oxygen species assay en-keyword=photosafety kn-keyword=photosafety END start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=4 article-no= start-page=045006 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=202155 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Modelling the visual response to an OUReP retinal prosthesis with photoelectric dye coupled to polyethylene film en-subtitle= kn-subtitle= en-abstract= kn-abstract=Objective. Retinal prostheses have been developed to restore vision in blind patients suffering from diseases like retinitis pigmentosa. Approach. A new type of retinal prosthesis called the Okayama University-type retinal prosthesis (OUReP) was developed by chemically coupling photoelectric dyes to a polyethylene film surface. The prosthesis works by passively generating an electric potential when stimulated by light. However, the neurophysiological mechanism of how OUReP stimulates the degenerated retina is unknown. Main results. Here, we explore how the OUReP affects retinal tissues using a finite element model to solve for the potential inside the tissue and an active Hodgkin-Huxley model based on rat vision to predict the corresponding retinal bipolar response. Significance. We show that the OUReP is likely capable of eliciting responses in retinal bipolar cells necessary to generate vision under most ambient conditions. en-copyright= kn-copyright= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=SundaramPrathima en-aut-sei=Sundaram en-aut-mei=Prathima kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=WongWilly en-aut-sei=Wong en-aut-mei=Willy kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Department of Electrical and Computer Engineering, University of Toronto kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=5 en-affil=Department of Electrical and Computer Engineering, University of Toronto kn-affil= en-keyword=retinal prosthesis kn-keyword=retinal prosthesis en-keyword=photoelectric dye kn-keyword=photoelectric dye en-keyword=boundary value problem kn-keyword=boundary value problem en-keyword=biophysical models of retinal cells kn-keyword=biophysical models of retinal cells END start-ver=1.4 cd-journal=joma no-vol=16 cd-vols= no-issue=4 article-no= start-page=045001 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=202138 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Development of highly durable retinal prosthesis using photoelectric dyes coupled to polyethylene film and quantitative in vitro evaluation of its durability en-subtitle= kn-subtitle= en-abstract= kn-abstract=Retinal prostheses have been developed to restore vision in blind patients suffering from such diseases as retinitis pigmentosa. In our previous studies, we developed a retinal prosthesis called dye-coupled film by chemical coupling of photoelectric dyes, which absorb light and then generate electrical potential, with a polyethylene film surface. The dye-coupled film is nontoxic, and we recovered the vision of a monkey with macular degeneration. The amount of dye on the dye-coupled film, however, decreased to one-third after five months in the monkeyfs eye. The photoelectric dye consists of a cation with photoresponsivity and a bromide ion (Br?). Therefore, an anion-exchange reaction could be applied to the dye-coupled film to improve its durability. In this study, the anion-exchange reaction was conducted using bis(trifluoromethanesulfonyl)imide ion (TFSI?), which has lower nucleophilicity than Br?. First, the long-term durability was examined without using animal subjects and in a short period. Subsequently, an elemental analysis was performed to confirm the exchange between Br? and TFSI?, and chemical properties, such as photoresponsivity and durability, before and after the anion exchange, were evaluated. It was quantitatively confirmed that the long-term durability of dye-coupled films can be evaluated in an in vitro environment and in a short period of one-thirtieth by utilizing a saline solution at 60‹C, compared with an in vivo environment. In addition, the durability of the dye-coupled film with TFSI? was improved to 270%?320% compared with that of the dye-coupled film with Br?. en-copyright= kn-copyright= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TanakaTenu en-aut-sei=Tanaka en-aut-mei=Tenu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=retinal prosthesis kn-keyword=retinal prosthesis en-keyword=photoelectric dye kn-keyword=photoelectric dye en-keyword=polyethylene film kn-keyword=polyethylene film en-keyword=retinitis pigmentosa kn-keyword=retinitis pigmentosa en-keyword=durability kn-keyword=durability END start-ver=1.4 cd-journal=joma no-vol=7 cd-vols= no-issue=1 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=2021 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Photoelectric dye-based retinal prosthesis (OUReP) as a novel type of artificial retina en-subtitle= kn-subtitle= en-abstract= kn-abstract=We have developed the world's first novel type of artificial retina, OUReP (Okayama University Retinal Prosthesis), in which a photoelectric dye that converts light energy into electric potential is covalently bonded to the surface of a polyethylene thin film as an insulator. The receptor that absorbs light and the output device that generates displacement current to stimulate nearby neurons are integrated in a sheet of thin film. It has become possible to measure the surface potential of the artificial retina OUReP using a Kelvin probe that measures the surface potential of semiconductors. When light is turned on and off to the artificial retina OUReP, the surface potential changes rapidly. As the light intensity is increased, the potential change on the surface of the artificial retina becomes larger. As for safety, the artificial retina OUReP was not toxic in all tests for biological evaluation of medical devices. As for efficacy, the artificial retina OUReP was implanted under the retina by vitreous surgery in monkey eyes which had chemically-induced macular degeneration with photoreceptor cell loss. Over the next 6 months, retinal detachment did not occur during the course, and the artificial retina was in contact with the retinal tissue. The amplitude of the visual evoked potential attenuated by macular degeneration recovered 1 month after implantation of the artificial retina, and the recovery of amplitude was maintained until 6 months after the implantation. By using multielectrode array-mounted dish recording system, it has been proved that action potential spikes are induced when the artificial retina is placed on degenerative retinal tissue of retinal dystrophic rats or mice and exposed to light, which is used as an index of the effectiveness of the artificial retina. We have established manufacturing and quality control of the device in a clean room facility, proved the safety and efficacy, and are preparing for first-in-human investigator-initiated clinical trials. en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Ophthalmology, Okayama University Hospital kn-affil= affil-num=2 en-affil=olymer Materials Science, Okayama University Graduate School of Natural Science and Technology, kn-affil= en-keyword=artificial retina kn-keyword=artificial retina en-keyword=retinal prosthesis kn-keyword=retinal prosthesis en-keyword=photoelectric dye kn-keyword=photoelectric dye en-keyword=polyethylene film kn-keyword=polyethylene film en-keyword=monkey surgery kn-keyword=monkey surgery en-keyword=multielectrode array dish recording kn-keyword=multielectrode array dish recording en-keyword=vitrectomy kn-keyword=vitrectomy en-keyword=disposable injector kn-keyword=disposable injector en-keyword=sustainable development goals kn-keyword=sustainable development goals END start-ver=1.4 cd-journal=joma no-vol=4 cd-vols= no-issue=3 article-no= start-page=1040 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200923 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Curved-Tip Disposable Injector (OUReP Injector) to Insert Photoelectric Dye-Coupled Polyethylene Film (OUReP) as Retinal Prosthesis into Subretinal Space of Rabbit Eyes en-subtitle= kn-subtitle= en-abstract= kn-abstract=The photoelectric dye-coupled thin polyethylene film functions as a novel type of retinal prosthesis in subretinal space of the eye. We previously reported a novel disposable injector to insert the thin film into subretinal space of the rabbit eye by vitreous surgery. The injection system composed of two separate parts, injector and loader. A circular film in 5 mm to 10 mm diameter was pulled into a transparent tube of the loader with a commercial 25-gauge forceps. The loader tube was joined with a sleeve to tube tip of the injector. The film in the loader was pushed with a plunger for the loader into the injector tube tip. The loader with the sleeve was removed from the injector tip, and the tube tip with the film was filled with solution. This study reported a small-bore curved-tip disposable injector with outer diameter of 1.6 mm. A curved-tip polypropylene tube was formed by the process of heating and cooling of the tube inserted with a curved guide wire. The plunger for the curved-tip tube was made of a polyphenylsulfone tip connected with a press-fitting inner polypropylene tube to a nylon rod. Bleb retinal detachment in 4 surgically aphakic eyes of rabbits were induced by infusing solution into subretinal space with a 38-gauge polyimide tip, and a retinal tear was made at the edge of retinal detachment with 25-gauge diathermy. The injector tip with the rolled film in 6 mm diameter was inserted from 2 mm wide scleral incision into vitreous and then into subretinal space. The rolled films were released into subretinal space with the tip end inserted into the retinal tear, and the released films were confirmed to stay under the retina with no additional aid. Dissection one month after surgeries confirmed successful implantation of 4 films into subretinal space of each rabbit eye. The curved-tip injector could release the rolled film into the subretinal space without additional effort, compared with the straight-tip injector, and would help surgeons implant photoelectric dye-coupled thin film retinal prosthesis easily at vitreous surgery. en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=matsuoChie en-aut-sei=matsuo en-aut-mei=Chie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TanakaTenu en-aut-sei=Tanaka en-aut-mei=Tenu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KawakamiYusuke en-aut-sei=Kawakami en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=HitomiToshiya en-aut-sei=Hitomi en-aut-mei=Toshiya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=TagaKanji en-aut-sei=Taga en-aut-mei=Kanji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=SanadaTatsuya en-aut-sei=Sanada en-aut-mei=Tatsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=YamashitaYusuke en-aut-sei=Yamashita en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Regenerative and Reconstructive Medicine (Ophthalmology), Okayama University Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=2 en-affil=Department of Regenerative and Reconstructive Medicine (Ophthalmology), Okayama University Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=3 en-affil=Department of Polymer Materials Science, Okayama University Faculty of Engineering and Graduate School of Natural Science and Technology kn-affil= affil-num=4 en-affil=Department of Polymer Materials Science, Okayama University Faculty of Engineering and Graduate School of Natural Science and Technology kn-affil= affil-num=5 en-affil=Department of Polymer Materials Science, Okayama University Faculty of Engineering and Graduate School of Natural Science and Technology kn-affil= affil-num=6 en-affil=Minori Industry Co. Ltd. kn-affil= affil-num=7 en-affil=Minori Industry Co. Ltd. kn-affil= affil-num=8 en-affil=Minori Industry Co. Ltd. kn-affil= affil-num=9 en-affil=Minori Industry Co. Ltd. kn-affil= affil-num=10 en-affil=Shin Nippon Biomedical Laboratories Ltd. kn-affil= en-keyword=Dye-coupled thin film retinal prosthesis kn-keyword=Dye-coupled thin film retinal prosthesis en-keyword=Curved-tip injector kn-keyword=Curved-tip injector en-keyword=Photoelectric dye kn-keyword=Photoelectric dye en-keyword=Rabbit kn-keyword=Rabbit en-keyword=25G vitrectomy kn-keyword=25G vitrectomy END start-ver=1.4 cd-journal=joma no-vol=5 cd-vols= no-issue= article-no= start-page=2903 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200810 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Step-by-Step Procedure to Test Photoelectric Dye-Coupled Polyethylene Film as Retinal Prosthesis to Induce Light-Evoked Spikes in Isolated Retinal Dystrophic Tissue of rd1 Mice en-subtitle= kn-subtitle= en-abstract= kn-abstract=Purpose: Multielectrode array recording for electric activity in cardiac and neuronal cells has been developed as preclinical tests for drug screening. This study aims to establish an in vitro assay system, using the multielectrode array, to record light-evoked spikes in isolated degenerative retinal tissues of retinal dystrophic rd1 mouse, as a preclinical test to examine the efficacy of photoelectric dye-coupled thin film retinal prosthesis.
Methods: Light-evoked spike response was tested for 1 min at first step in the isolated degenerative retinal tissue of retinal dystrophic rd1 mouse only on the multielectrode array, tested in the same retinal tissue overlain with a plain control film for light-off and light-on 10 min each at second step, and tested in the same tissue overlain with a dye-coupled film at third step. The retinal tissues which showed light-evoked response at first or second step were not used for evaluation at third step.
Results: Residual light-evoked spikes were recorded at first or second step in 18 of 35 retinal tissues (51%) at 6 weeks of the age in rd1 mice, 16 of 44 tissues (36%) at 7 weeks, and 10 of 39 tissues (25%) at 8 weeks. At third step, light-evoked spikes were recorded with dye-coupled films in 8 of 17 retinal tissues (47%) at 6 weeks, 10 of 28 tissues (35%) at 7 weeks, and 8 of 29 tissues (27%) at 8 weeks.
Conclusion: A step-by-step procedure with internal control was established to measure light-evoked spikes by the multielectrode array in the isolated degenerative retinal tissue to evaluate photoelectric dye-coupled thin films. This preclinical study would present one line of evidence for the efficacy of photoelectric dye-coupled thin film retinal prosthesis towards a first-in-human clinical trial. en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TeradaKeiko en-aut-sei=Terada en-aut-mei=Keiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SakuraiMikako en-aut-sei=Sakurai en-aut-mei=Mikako kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=LiuShihu en-aut-sei=Liu en-aut-mei=Shihu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Regenerative and Reconstructive Medicine (Ophthalmology), Okayama University Medical School and Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=2 en-affil=Research Center, Techno Pro, Inc. kn-affil= affil-num=3 en-affil=Research Center, Techno Pro, Inc. kn-affil= affil-num=4 en-affil=Regenerative and Reconstructive Medicine (Ophthalmology), Okayama University Medical School and Graduate School of Interdisciplinary Science and Engineering in Health Systems kn-affil= affil-num=5 en-affil=Polymer Materials Science, Okayama University Faculty of Engineering and Graduate School of Natural Science and Technology kn-affil= affil-num=6 en-affil=Polymer Materials Science, Okayama University Faculty of Engineering and Graduate School of Natural Science and Technology kn-affil= en-keyword=Photoelectric dye kn-keyword=Photoelectric dye en-keyword=Polyethylene thin film kn-keyword=Polyethylene thin film en-keyword=Spike kn-keyword=Spike en-keyword=Degenerative retina kn-keyword=Degenerative retina en-keyword=Retinal dystrophic rd1 mouse kn-keyword=Retinal dystrophic rd1 mouse END start-ver=1.4 cd-journal=joma no-vol=202 cd-vols= no-issue= article-no= start-page=122672 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200812 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Preparation of solution-grown lozenge-shaped poly(p-phenylene terephthalamide) single crystals and their structural stabilization by heat treatment en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this study, the preparation of poly (p-phenylene terephthalamide) (PPTA) single crystals was examined using crystallization from dilute solutions in concentrated sulfuric acid. Lozenge-shaped PPTA single crystals were successfully prepared using a self-seeding method with a low degree of supercooling, and they consisted of modification I crystals. The a-axis direction of the crystal corresponded to the long diagonal direction of the rhombus, the b-axis direction with the short diagonal direction, and the PPTA molecular chain direction (the c-axis direction) with the crystal's thickness direction. In addition, the PPTA single crystals had a (110) growth plane, where the thickness of each single crystal was approximately equal to the molecular chain length of the PPTA. Upon heat treatment of the PPTA single crystals, the symmetry changed from P1a1 to the more stable P11n. In addition, the heat treatment caused a difference in the density of each symmetric crystal, resulting in crack formation along the b-axis direction, which is the hydrogen-bonding direction. However, the heat treatment did not change the thickness of the PPTA single crystals. Conversely, the isothermal crystallization of the PPTA caused progression in the crystallization only under a high degree of supercooling, thus yielding plate-like PPTA crystals that consisted of modification II crystals. In these plate-like PPTA crystals, the length corresponded to the crystal a-axis direction, and the electron diffraction pattern was broad. Furthermore, the equilibrium dissolution temperature of the PPTA single crystals was discussed. en-copyright= kn-copyright= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=HaraYutaro en-aut-sei=Hara en-aut-mei=Yutaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakakiTomoyasu en-aut-sei=Takaki en-aut-mei=Tomoyasu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Poly(p-phenylene terephthalamide) kn-keyword=Poly(p-phenylene terephthalamide) en-keyword=Single crystals kn-keyword=Single crystals en-keyword=Heat treatment kn-keyword=Heat treatment END start-ver=1.4 cd-journal=joma no-vol=5 cd-vols= no-issue=6 article-no= start-page=e01936 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190630 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Vision evaluation by functional observational battery, operant behavior test, and light/dark box test in retinal dystrophic RCS rats versus normal rats en-subtitle= kn-subtitle= en-abstract= kn-abstract=BACKGROUND:
Vision plays a key role in some behavior tests for rats. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to assess vision in retinal dystrophic (RCS) rats, in comparison with normal rats, by selected behavior tests. We also examined whether the tests could detect vision changes in RCS rats with dye-coupled film implantation.
METHODS:
Data sets were 5 normal rats, 4 untreated RCS rats, 7 RCS rats with dye-coupled films implanted at the age of 7 weeks after excluding unsuccessful implantation at autopsy. Behavior tests chosen were landing foot splay and visual forelimb-placing response in the menu of functional observational battery, operant-conditioning lever-press response and light/dark box test.
RESULTS:
Normal visual placing response was significantly less frequent in untreated RCS rats at the age of 9 and 11 weeks, compared with normal rats (P = 0.0027, chi-square test) while normal response was significantly more frequent at the age of 9 weeks in RCS rats with dye-coupled film implantation, compared with untreated RCS rats (P = 0.0221). In operant-conditioning lever-press test, the correct response rate was significantly lower in untreated RCS rats than in normal rats at the age of 9 weeks (P < 0.05, Tukey-Kramer test) while the rate was not significantly different between normal rats and RCS rats with dye-coupled film implantation. In light/dark box test, the time to enter dark box was significantly shorter in normal rats, compared with untreated RCS rats or RCS rats with dye-coupled film implantation (P < 0.05, Tukey-Kramer test).
CONCLUSIONS:
Behavior tests of functional observational battery, operant-conditioning lever-press response and light/dark box test discriminated vision between normal rats and RCS rats. The visual placing response and operant-conditioning lever-press test might have sensitivity to detect vision recovery in RCS rats with OUReP implantation. en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamashitaKoichiro en-aut-sei=Yamashita en-aut-mei=Koichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=Takei Shigiko en-aut-sei=Takei en-aut-mei= Shigiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Ido Daisuke en-aut-sei=Ido en-aut-mei= Daisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=Fujiwara Atsushi en-aut-sei=Fujiwara en-aut-mei= Atsushi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=Iino Masahiko en-aut-sei=Iino en-aut-mei= Masahiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=Oguchi Masao en-aut-sei=Oguchi en-aut-mei= Masao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Ophthalmology, Okayama University Medical School and Okayama University Hospital kn-affil= affil-num=2 en-affil=Polymer Materials Science, Okayama University Graduate School of Natural Science and Technology kn-affil= affil-num=3 en-affil=Polymer Materials Science, Okayama University Graduate School of Natural Science and Technology kn-affil= affil-num=4 en-affil=Ina Research kn-affil= affil-num=5 en-affil=Ina Research kn-affil= affil-num=6 en-affil=Ina Research kn-affil= affil-num=7 en-affil=Ina Research kn-affil= affil-num=8 en-affil=Ina Research kn-affil= en-keyword=Bioengineering kn-keyword=Bioengineering en-keyword=Neuroscience kn-keyword=Neuroscience en-keyword=Physiology kn-keyword=Physiology en-keyword=Zoology kn-keyword=Zoology END start-ver=1.4 cd-journal=joma no-vol=127 cd-vols= no-issue=3 article-no= start-page=223 end-page=229 dt-received= dt-revised= dt-accepted= dt-pub-year=2015 dt-pub=20151201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Investigator (doctor)-initiated clinical trial of photoelectric dye-coupled thin film (Okayama University-type) retinal prosthesis kn-title=F‘fŒ‹‡”––ŒŒ^i‰ªŽR‘åŠw•ûŽ®j‚ÌlH–Ô–ŒiOURePTMj‚̈ãŽtŽå“±Ž¡Œ± en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name=¼”ör•F kn-aut-sei=¼”ö kn-aut-mei=r•F aut-affil-num=1 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=2 ORCID= affil-num=1 en-affil= kn-affil=‰ªŽR‘åŠw‘åŠw‰@ˆãŽ•–òŠw‘‡Œ¤‹†‰È affil-num=2 en-affil= kn-affil=‰ªŽR‘åŠw‘åŠw‰@Ž©‘R‰ÈŠwŒ¤‹†‰È en-keyword=lH–Ô–Œ kn-keyword=lH–Ô–Œ en-keyword=OUReP kn-keyword=OUReP en-keyword=ˆãŽtŽå“±Ž¡Œ± kn-keyword=ˆãŽtŽå“±Ž¡Œ± en-keyword=F‘fŒ‹‡”––Œ kn-keyword=F‘fŒ‹‡”––Œ en-keyword=–Ô–ŒF‘f•Ï« kn-keyword=–Ô–ŒF‘f•Ï« END start-ver=1.4 cd-journal=joma no-vol=3 cd-vols= no-issue= article-no= start-page=317 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2014 dt-pub=20140625 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Glass transition temperature of dried lens tissue pretreated with trehalose, maltose, or cyclic tetrasaccharide en-subtitle= kn-subtitle= en-abstract= kn-abstract=[PURPOSE] Glass transition temperature is a main indicator for amorphous polymers and biological macromolecules as materials, and would be a key for understanding the role of trehalose in protecting proteins and cells against desiccation. In this study, we measured the glass transition temperature by differential scanning calorimetry of dried lens tissues as a model of a whole biological tissue to know the effect of pretreatment by trehalose and other sugars. [METHODS] Isolated porcine lenses were incubated with saline, 100 or 1000 mM concentration of trehalose, maltose, or cyclic tetrasaccharide dissolved in saline at room temperature for 150 minutes. The solutions were removed and all samples were dried at room temperature in a desiccator until no weight change. The dried tissues were ground into powder and placed in a measuring pan for differential scanning calorimetry. [RESULTS] The glass transition temperature of the dried lens tissues, as a mean and standard deviation, was 63.0?}?6.4‹C (n?=?3) with saline pretreatment; 53.0?}?0.8‹C and 56.3?}?2.7‹C (n?=?3), respectively, with 100 and 1000 mM trehalose pretreatment; 56.0?}?1.6‹C and 55.8?}?1.1‹C (n?=?3), respectively, with 100 and 1000 mM maltose pretreatment; 60.0?}?8.8‹C and 59.2?}?6.3‹C (n?=?3), respectively, with 100 and 1000 mM cyclic tetrasaccharide pretreatment. The glass transition temperature appeared lower, although not significantly, with trehalose and maltose pretreatments than with saline and cyclic tetrasaccharide pretreatments (P?>?0.05, Kruskal-Wallis test). The glass transition temperature of the dried lens tissues with trehalose pretreatment appeared more noticeable on the thermogram, compared with other pretreatments. [CONCLUSIONS] The glass transition temperature was measured for the first time in the dried lens tissues as an example of a whole biological tissue and might provide a basis for tissue preservation in the dried condition. en-copyright= kn-copyright= en-aut-name=KawataTetsuhiro en-aut-sei=Kawata en-aut-mei=Tetsuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Department of Ophthalmology, Okayama University Medical School and Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences affil-num=2 en-affil= kn-affil=Department of Ophthalmology, Okayama University Medical School and Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences affil-num=3 en-affil= kn-affil=Division of Polymer Materials Science, Faculty of Engineering and Okayama University Graduate School of Natural Science and Technology en-keyword=Trehalose kn-keyword=Trehalose en-keyword=Glass transition temperature kn-keyword=Glass transition temperature en-keyword=Lens kn-keyword=Lens en-keyword=Differential scanning calorimetry kn-keyword=Differential scanning calorimetry en-keyword=Desiccation; Maltose kn-keyword=Desiccation; Maltose en-keyword=Cyclic tetrasaccharide kn-keyword=Cyclic tetrasaccharide en-keyword=Biological tissue kn-keyword=Biological tissue en-keyword=Tissue preservation kn-keyword=Tissue preservation en-keyword=Regenerative medicine kn-keyword=Regenerative medicine END start-ver=1.4 cd-journal=joma no-vol=16 cd-vols= no-issue=3 article-no= start-page=343 end-page=351 dt-received= dt-revised= dt-accepted= dt-pub-year=2013 dt-pub=201309 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Behavior tests and immunohistochemical retinal response analyses in RCS rats with subretinal implantation of Okayama-University-type retinal prosthesis en-subtitle= kn-subtitle= en-abstract= kn-abstract=We have developed a photoelectric dye-coupled polyethylene film as a prototype of retinal prosthesis, which we named Okayama University-type retinal prosthesis. The purposes of this study are to conduct behavior tests to assess vision in Royal College of Surgeons (RCS) rats that underwent subretinal implantation of the dye-coupled film and to reveal retinal response to the dye-coupled film by immunohistochemistry. Polyethylene films were made of polyethylene powder at refined purity, and photoelectric dyes were coupled to the film surface at higher density compared with the prototype. Either dye-coupled film or dye-uncoupled plain film used as a control was implanted subretinally from a scleral incision in both eyes of an RCS rat at 6 weeks of the age. Behavior tests 2, 4, 6, and 8 weeks after implantation were conducted by observing head turning or body turning in the direction consistent with clockwise or counterclockwise rotation of a black-and-white-striped drum around a transparent cage housed with the rat. After the behavior tests at 8 weeks, rats' eyes were enucleated to confirm subretinal implantation of the films and processed for immunohistochemistry. In the behavior tests, the number of head turnings consistent with the direction of the drum rotation was significantly larger in RCS rats with dye-coupled- compared with plain-film implantation [P < 0.05, repeated-measure analysis of variance (ANOVA), n = 7]. The number of apoptotic neurons was significantly smaller in eyes with dye-coupled- compared with plain-film implantation (P < 0.05, Mann-Whitney U test, n = 6). In conclusion, subretinal implantation of photoelectric dye-coupled films restored vision in RCS rats and prevented the remaining retinal neurons from apoptosis. en-copyright= kn-copyright= en-aut-name=Alamusi en-aut-sei=Alamusi en-aut-mei= kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HosoyaOsamu en-aut-sei=Hosoya en-aut-mei=Osamu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TsutsuiKimiko M. en-aut-sei=Tsutsui en-aut-mei=Kimiko M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil= kn-affil=Okayama Univ Med Sch, Dept Ophthalmol affil-num=2 en-affil= kn-affil=Okayama Univ Med Sch, Dept Ophthalmol affil-num=3 en-affil= kn-affil=Okayama Univ Med Sch, Dept Neurogen affil-num=4 en-affil= kn-affil=Okayama Univ Med Sch, Dept Neurogen affil-num=5 en-affil= kn-affil=Okayama Univ Fac Engn, Div Polymer Mat Sci en-keyword=Retinal prosthesis kn-keyword=Retinal prosthesis en-keyword=Photoelectric dye kn-keyword=Photoelectric dye en-keyword=Polyethylene film kn-keyword=Polyethylene film en-keyword=RCS rat kn-keyword=RCS rat en-keyword=Behavior test kn-keyword=Behavior test en-keyword=Apoptosis kn-keyword=Apoptosis en-keyword=Immunohistochemistry kn-keyword=Immunohistochemistry END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=1 article-no= start-page=11 end-page=17 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=19961227 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Synthesis and Characterization of Poly[(benzo[1,2-d:5,4-d']bisthiazole-2,6-diyl)-1,4-phenylene] en-subtitle= kn-subtitle= en-abstract= kn-abstract=Poly[(benzo[1,2-d:5,4-d']bissthiazole-2,6-diyl)-1,4-phenylene](cis-PBZT)with a relatively high molecular weight was prepared by a new synthesis route. Properties of the synthesized polymer, such as thermostability, liquid crystallinity etc. were investigated and compared with those of trans-PBZT. cis-PBZT was crystallized from dilute solution and the electron microscopy showed that the precipitate was a rod-like crystal similar to that of trans form. In spite of rigid nature of the back bone, cis-PBZT showed poor crystallinity. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=ZhangChunxiao kn-aut-sei=Zhang kn-aut-mei=Chunxiao aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=TanigawaSatoshi kn-aut-sei=Tanigawa kn-aut-mei=Satoshi aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=3 ORCID= en-aut-name=ShimamuraKaoru en-aut-sei=Shimamura en-aut-mei=Kaoru kn-aut-name=“‡‘ºŒO kn-aut-sei=“‡‘º kn-aut-mei=ŒO aut-affil-num=4 ORCID= affil-num=1 en-affil= kn-affil=Department of Applied Chemistry affil-num=2 en-affil= kn-affil=Department of Applied Chemistry affil-num=3 en-affil= kn-affil=Department of Applied Chemistry affil-num=4 en-affil= kn-affil=Department of Applied Chemistry END start-ver=1.4 cd-journal=joma no-vol=31 cd-vols= no-issue=1 article-no= start-page=5 end-page=10 dt-received= dt-revised= dt-accepted= dt-pub-year=1996 dt-pub=19961227 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Solution-Grown Crystals of Poly(p-phenylene benzobisthiazole) en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rigid polymer poly(p-phenylene benzobisthiazole) was crystallized from dilute solution. Electron microscopy showed that upon quenching, flat fibrils with several nm thick were produced. Subsequent heat treatment in solvent changed the fibril into "shish-kebab". On the other hand, by isothermal crystallization, an aggregate of parallel rod-like crystals was obtained. The molecular chains were accommodated normal to the rod. Based on the observation of crystal morphology, the isothermal crystallization mechanism was proposed. Because of regidity of polymer chains and wide distribution of the molecular length, the chain ends were inevitably included within the crystals resulting in crystal defects such as axial shift, lattice curvature and edge dislocation which were directly observed by lattice imaging. en-copyright= kn-copyright= en-aut-name=ShimamuraKaoru en-aut-sei=Shimamura en-aut-mei=Kaoru kn-aut-name=“‡‘ºŒO kn-aut-sei=“‡‘º kn-aut-mei=ŒO aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=ZhangChunxiao kn-aut-sei=Zhang kn-aut-mei=Chunxiao aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Department of Applied Chemistry affil-num=2 en-affil= kn-affil=Department of Applied Chemistry affil-num=3 en-affil= kn-affil=Department of Applied Chemistry END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=1-2 article-no= start-page=35 end-page=40 dt-received= dt-revised= dt-accepted= dt-pub-year=2001 dt-pub=20010327 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Scanning Probe Microscopy of Poly(p-phenylene benzobisthiazole) Lamellar Crystal en-subtitle= kn-subtitle= en-abstract= kn-abstract=Rigid polymer, poly(p-phenylene benzobisthiazole), formed lamellar crystals where the molecular chains were oriented perpendicular to the lamellae. It was supposed that, because of wide distribution in the chain length, the lamellar surface bristled with the chain cilia among which many voids were included. Crystallographically, this region afforded us a transitional structure from full to deficient packings of chains. The structure was analyzed using the scanning probe microscope. In the course the method for imaging one molecular chain end was developed. From the images it was concluded that an isolated long cilius did not move so violently at room temperature. en-copyright= kn-copyright= en-aut-name=ShimamuraKaoru en-aut-sei=Shimamura en-aut-mei=Kaoru kn-aut-name=“‡‘ºŒO kn-aut-sei=“‡‘º kn-aut-mei=ŒO aut-affil-num=1 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=2 ORCID= en-aut-name=InoueTomohiro en-aut-sei=Inoue en-aut-mei=Tomohiro kn-aut-name=ˆäã’q”Ž kn-aut-sei=ˆäã kn-aut-mei=’q”Ž aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Department of Applied Chemistry affil-num=2 en-affil= kn-affil=Department of Applied Chemistry affil-num=3 en-affil= kn-affil=Department of Applied Chemistry END start-ver=1.4 cd-journal=joma no-vol=35 cd-vols= no-issue=1-2 article-no= start-page=29 end-page=34 dt-received= dt-revised= dt-accepted= dt-pub-year=2001 dt-pub=20010327 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Synthesis of Poly(ethylene-block-vinylalcohol)for Use as Amphiphilic Film Surface at High Temperature en-subtitle= kn-subtitle= en-abstract= kn-abstract=Poly (ethylene-block-vinyl alcohol), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO(2) at the ends (the chain length were almost same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e., methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block co-polymer. The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophobic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. The surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable at room temperature. en-copyright= kn-copyright= en-aut-name=ShimamuraKaoru en-aut-sei=Shimamura en-aut-mei=Kaoru kn-aut-name=“‡‘ºŒO kn-aut-sei=“‡‘º kn-aut-mei=ŒO aut-affil-num=1 ORCID= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=MunesawaYuhji kn-aut-sei=Munesawa kn-aut-mei=Yuhji aut-affil-num=2 ORCID= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=3 ORCID= affil-num=1 en-affil= kn-affil=Department of Applied Chemistry affil-num=2 en-affil= kn-affil=Department of Applied Chemistry affil-num=3 en-affil= kn-affil=Department of Applied Chemistry END start-ver=1.4 cd-journal=joma no-vol=39 cd-vols= no-issue=1 article-no= start-page=16 end-page=20 dt-received= dt-revised= dt-accepted= dt-pub-year=2005 dt-pub=200501 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Immobilization of Photoelectric Dye on the Polyethylene FilmSurface en-subtitle= kn-subtitle= en-abstract= kn-abstract=PE film was treated with fuming nitric acid at 80Ž for 20 min, resulting in introduction of COOH moieties on the film surface. The COOHfs were reacted with ethylenediamine, whose amino groups were used for linking with (2-[4-(dibutylamino)phenyl]ethenyl)-3-carboxy-methylbenzo-thiazolium, photoelectric dye (NK-5962), which absorbs visible light and converts the photon energy to electric potentials. The dye molecules were immobilized on the PE film surface and they were able to stimulate chick retinal tissues on incidence of visible light. These facts hopefully lead to development of an artificial retinal prosthesis. en-copyright= kn-copyright= en-aut-name=UchidaTetsuya en-aut-sei=Uchida en-aut-mei=Tetsuya kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=1 ORCID= en-aut-name=IshimaruSanae en-aut-sei=Ishimaru en-aut-mei=Sanae kn-aut-name=Ίۑ•c kn-aut-sei=ÎŠÛ kn-aut-mei=‘•c aut-affil-num=2 ORCID= en-aut-name=ShimamuraKaoru en-aut-sei=Shimamura en-aut-mei=Kaoru kn-aut-name=“‡‘ºŒO kn-aut-sei=“‡‘º kn-aut-mei=ŒO aut-affil-num=3 ORCID= en-aut-name=UjiAkihito en-aut-sei=Uji en-aut-mei=Akihito kn-aut-name=‰FŽ¡Íl kn-aut-sei=‰FŽ¡ kn-aut-mei=Íl aut-affil-num=4 ORCID= en-aut-name=MatsuoToshihiko en-aut-sei=Matsuo en-aut-mei=Toshihiko kn-aut-name=¼”ör•F kn-aut-sei=¼”ö kn-aut-mei=r•F aut-affil-num=5 ORCID= en-aut-name=OhtsukiHiroshi en-aut-sei=Ohtsuki en-aut-mei=Hiroshi kn-aut-name=‘匎—m kn-aut-sei=‘匎 kn-aut-mei=—m aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil= affil-num=2 en-affil= kn-affil= affil-num=3 en-affil= kn-affil= affil-num=4 en-affil= kn-affil= affil-num=5 en-affil= kn-affil= affil-num=6 en-affil= kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2002 dt-pub=20020930 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=„’¼‚•ªŽq‚ÌŒ‹»‚¨‚æ‚щˋ´‘Ì‚Ì\‘¢‚ÉŠÖ‚·‚錤‹† en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=“à“c“N–ç kn-aut-sei=“à“c kn-aut-mei=“N–ç aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=‰ªŽR‘åŠw END