Co-reporter:Zha Li, Pan He, Hui Chong, Akihiro Furube, Kazuhiko Seki, Hsiao-hua Yu, Keisuke Tajima, Yoshihiro Ito, and Masuki Kawamoto
ACS Omega April 2017? Volume 2(Issue 4) pp:1625-1625
Publication Date(Web):April 25, 2017
DOI:10.1021/acsomega.7b00175
Single-walled carbon nanotubes (SWCNTs) have received much attention because of their potential in optoelectronic applications. Pristine SWCNTs exhibit substantial van der Waals interactions and hydrophobic characteristics, so precipitation occurs immediately in most organic solvents and water. Highly toxic and hazardous chemicals are often used to obtain well-dispersed SWCNTs. Developing environmentally friendly processing methods for safe and practical applications is a great challenge. Here, we demonstrate direct exfoliation of SWCNTs in pure water only with n-type semiconducting fullerene nanoparticles. The resultant SWCNTs can be well-dispersed in water, where they remain essentially unchanged for several weeks. Adding an aqueous solution of p-type semiconducting water-soluble polythiophene yields self-assembled p/n heterojunctions between polythiophene and the nanoparticles. The aqueous-dispersed SWCNTs yield photocurrent responses in solution-processed thin films as a potential application of water-dispersed carbon nanomaterials.Topics: Carbon nanostructured materials; Composites; Dispersion of materials; Distribution function; Electric transport processes and properties; Magnetic processes; Mechanical properties; Nanoclusters; Nanoparticles; Self-assembly; Spectra;
Co-reporter:Hongli Mao;Seong Min Kim;Masashi Ueki
Journal of Materials Chemistry B 2017 vol. 5(Issue 5) pp:928-934
Publication Date(Web):2017/02/01
DOI:10.1039/C6TB02867E
In vitro expansion of human mesenchymal stem cells (hMSCs) using serum-free culture medium is important for basic research and clinical applications. It is known that some growth factors are required for developing a defined medium for hMSC culture. However, growth factors usually show poor stability, short circulating half-life and a rapid rate of cellular internalization when they are in a diffusible state. A potential way to overcome these problems is to immobilize growth factors on materials. Here, three different types of growth factors, basic fibroblast growth factor, transforming growth factor-beta, and platelet-derived growth factor, were co-immobilized on cell culture dish surfaces by photo-reactive gelatin and used for serum-free hMSC cultures. The results showed that the immobilized growth factors supported cell proliferation similarly to the serum-containing medium. More importantly, the immobilization of growth factors significantly improved their thermal stability and efficiently prolonged their shelf life at 4 °C and 37 °C. Furthermore, the immobilized growth factors could be reused at least three times without losing their stimulation effect on cell proliferation. This photo-reactive gelatin-based immobilization of growth factors appears to be a promising method for serum-free hMSC culturing.
Co-reporter:Masuki Kawamoto;Pan He
Advanced Materials 2017 Volume 29(Issue 25) pp:
Publication Date(Web):2017/07/01
DOI:10.1002/adma.201602423
Carbon nanomaterials (CNMs) from fullerenes, carbon nanotubes, and graphene are promising carbon allotropes for various applications such as energy-conversion devices and biosensors. Because pristine CNMs show substantial van der Waals interactions and a hydrophobic nature, precipitation is observed immediately in most organic solvents and water. This inevitable aggregation leads to poor processability and diminishes the intrinsic properties of the CNMs. Highly toxic and hazardous chemicals are used for chemical and physical modification of CNMs, even though efficient dispersed solutions are obtained. The development of an environmentally friendly dispersion method for both safe and practical processing is a great challenge. Recent green processing approaches for the manipulation of CNMs using chemical and physical modification are highlighted. A summary of the current research progress on: i) energy-efficient and less-toxic chemical modification of CNMs using covalent-bonding functionality and ii) non-covalent-bonding methodologies through physical modification using green solvents and dispersants, and chemical-free mechanical stimuli is provided. Based on these experimental studies, recent advances and challenges for the potential application of green-processable energy-conversion and biological devices are provided. Finally, a conclusion section is provided summarizing the insights from the present studies as well as some future perspectives.
Co-reporter:Yasodha Manandhar;Wei Wang;Jin Inoue;Nobuhiro Hayashi
Biotechnology Letters 2017 Volume 39( Issue 3) pp:375-382
Publication Date(Web):2017 March
DOI:10.1007/s10529-016-2257-2
We examined the importance of aptamer usage under the same condition as the selection process by employing the previously selected aptamers for calmodulin (CaM) which includes a non-natural fluorogenic amino acid, 7-nitro-2,1,3-benzoxadiazole.We added five amino acids at the N-terminus which was employed for the selection and then we tested the affinity and selectivity for CaM binding. Surface plasmon resonance and fluorescence measurements showed that the additional amino acids for one of the aptamers drastically improved binding affinity to CaM, indicating the importance of aptamer use under the same conditions as the selection process. Such drastic improvement in affinity was not observed for the sequence which had been reported previously. Nuclear magnetic resonance data identified that the primary binding site is located in a C-terminal of CaM and the additional residues enhance interactions with CaM.We found that the addition of the common sequence, which was employed for ribosome display, makes the affinity of a selected peptide as strong as the previously reported peptide.
Co-reporter:Baiju G. Nair;Yue Zhou;Kyoji Hagiwara;Masashi Ueki;Takashi Isoshima;Hiroshi Abe
Journal of Materials Chemistry B 2017 vol. 5(Issue 22) pp:4044-4051
Publication Date(Web):2017/06/07
DOI:10.1039/C7TB00846E
Nanostructured RNA carrying three different siRNAs was assembled to silence three target genes (Axin, APC, and GSK-3β) in the Wnt/β-catenin signaling pathway. The trimer RNA nanostructure included equimolar concentrations of three oligonucleotide sequences. The three armed structures and the size of the trimer RNA were confirmed by agarose gel electrophoresis, atomic force microscopy, and dynamic light scattering. In the presence of 10% human serum, the trimer RNA was able to resist degradation and maintained an intact structure for more than two hours. Protein expression analyses showed specific repression of the target proteins by siRNAs. As a result, the expression of luciferase in a β-catenin reporter vector was significantly increased by the trimer RNA compared with a pool of the three individual siRNAs. This high activity at a low concentration was considered to be due to the 3-in-1 format of the trimer and the long-term resistance to serum proteins by nanostructure formation. We demonstrated that a nanostructured “3-in-1” siRNA is effective in enhancing the effect of RNA interference.
Co-reporter:Baiju G. Nair, Kyoji Hagiwara, Motoki Ueda, Hsiao-hua Yu, Hsian-Rong Tseng, and Yoshihiro Ito
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 29) pp:18693-18700
Publication Date(Web):July 15, 2016
DOI:10.1021/acsami.6b04913
High aspect ratio nanomaterials, such as vertically aligned silicon nanowire (SiNW) substrates, are three-dimensional topological features for cell manipulations. A high density of SiNWs significantly affects not only cell adhesion and proliferation but also the delivery of biomolecules to cells. Here, we used polydopamine (PD) that simply formed a thin coating on various material surfaces by the action of dopamine as a bioinspired approach. The PD coating not only enhanced cell adhesion, spreading, and growth but also anchored more siRNA by adsorption and provided more surface concentration for substrate-mediated delivery. By comparing plain and SiNW surfaces with the same amount of loaded siRNA, we quantitatively found that PD coating efficiently anchored siRNA on the surface, which knocked down the expression of a specific gene by RNA interference. It was also found that the interaction of SiNWs with the cell membrane perturbed the lateral diffusion of lipids in the membrane by fluorescence recovery after photobleaching. The perturbation was considered to induce the effective delivery of siRNA into cells and allow the cells to carry out their biological functions. These results suggest promising applications of PD-coated, high-density SiNWs as simple, fast, and versatile platforms for transmembrane delivery of biomolecules.
Co-reporter:Wei Wang, Liping Zhu, Yoshinori Hirano, Marziyeh Kariminavargani, Seiichi Tada, Guanxin Zhang, Takanori Uzawa, Deqing Zhang, Takuji Hirose, Makoto Taiji, and Yoshihiro Ito
Analytical Chemistry 2016 Volume 88(Issue 16) pp:7991
Publication Date(Web):July 26, 2016
DOI:10.1021/acs.analchem.6b01032
To prepare a fluorogenic peptide ligand which binds to an arbitrary target, we previously succeeded in seeking a fluorogenic ligand to calmodulin using in vitro selection. In this study the environment-sensitive fluorescent group in the selected peptide ligand was replaced with other fluorescent groups to find the possibility to increase the fluorogenic activity. Surface plasmon resonance measurement exhibited that the binding affinity was held even after the replacement. However, the replacement significantly affected the fluorogenic activity. It depended on the kind of incorporated fluorophors and linker length. As a result, the incorporation of 4-N,N-dimethylamino-1,8-naphthalimide enhanced the fluorescence intensity over 100-fold in the presence of target calcium-bound calmodulin. This study demonstrated that the functionality of in vitro selected peptide can be tuned with keeping the binding affinity.
Co-reporter:Qingmin Zang, Seiichi Tada, Takanori Uzawa, Daisuke Kiga, Masayuki Yamamura and Yoshihiro Ito
Chemical Communications 2015 vol. 51(Issue 76) pp:14385-14388
Publication Date(Web):31 Jul 2015
DOI:10.1039/C5CC04486C
Polyethylene glycol (PEG) of different lengths was genetically incorporated into the backbone of a polypeptide using stop-anticodon and frameshift anticodon-containing tRNAs, which were acylated with PEG-containing amino acids.
Co-reporter:Liping Zhu, Wei Wang, Haixu Zhao, Muye Xu, Seiichi Tada, Takanori Uzawa, Mingzhe Liu and Yoshihiro Ito
Organic & Biomolecular Chemistry 2015 vol. 13(Issue 38) pp:9808-9812
Publication Date(Web):04 Aug 2015
DOI:10.1039/C5OB01271F
When minimal functional sequences are used, it is possible to integrate multiple functions on a single peptide chain, like a “single stroke drawing”. Here a dual functional peptide was designed by combining in vitro selected catalytic and binding activities. For catalytic activity, we performed in vitro selection for a peptide aptamer binding to hemin by using ribosome display and isolated a peptide that had peroxidase activity in the presence of hemin. By combining the selected catalytic peptide with a peptide antigen, which can be recognized by an antibody, an enzyme–antibody conjugate-like peptide was obtained. This study demonstrates a successful strategy to create dual functionalized peptide chains for use in immunoassays.
Co-reporter:Siyoong Seo, Kazumitsu Onizuka, Chieko Nishioka, Eiki Takahashi, Satoshi Tsuneda, Hiroshi Abe and Yoshihiro Ito
Organic & Biomolecular Chemistry 2015 vol. 13(Issue 15) pp:4589-4595
Publication Date(Web):06 Mar 2015
DOI:10.1039/C5OB00199D
The representative DNA-labeling agent 5-ethynyl-2′-deoxyuridine (EdU) was chemically modified to improve its function. Chemical monophosphorylation was expected to enhance the efficiency of the substrate in DNA polymerization by circumventing the enzymatic monophosphorylation step that consumes energy. In addition, to enhance cell permeability, the phosphates were protected with bis-pivaloyloxymethyl that is stable in buffer and plasma, and degradable inside various cell types. The phosphorylated EdU (PEdU) was less toxic than EdU, and had the same or a slightly higher DNA-labeling ability in vitro. PEdU was also successfully applied to DNA labeling in vivo. In conclusion, PEdU can be used as a less toxic DNA-labeling agent for studies that require long-term cell survival or very sensitive cell lines.
Co-reporter:Zha Li, Tomoshi Kameda, Takashi Isoshima, Eiry Kobatake, Takeshi Tanaka, Yoshihiro Ito, and Masuki Kawamoto
Langmuir 2015 Volume 31(Issue 11) pp:3482-3488
Publication Date(Web):March 6, 2015
DOI:10.1021/la504777b
The solubilizing ability of single-walled carbon nanotubes (SWCNTs) in water with several dispersants was investigated. Among the dispersants, including low-molecular-weight surfactants, peptides, DNA, and a water-soluble polymer, the peptide aptamer, A2 (IFRLSWGTYFS), exhibited the highest dispersion capability below the critical micelle concentration at a concentration of 0.02 w/v%. The dispersion of supernatant aqueous solution of SWCNTs containing aptamer A2 was essentially unchanged for several months after high-speed ultracentrifugation and gave rise to an efficient and stable dispersion of the SWCNTs in water. From the results of isothermal titration calorimetry and molecular dynamics simulations, the effective binding capability of A2 was due to π–π interaction between aromatic groups in the peptide aptamer and the side walls of SWCNTs. Interestingly, the peptide aptamer showed the possibility of diameter separation of semiconducting SWCNTs using a uniform density gradient ultracentrifuge. These phenomena are encouraging results toward an effective approach to the dispersion and separation of SWCNTs.
Co-reporter:Yasodha Manandhar;K. C. Tara Bahadur;Wei Wang;Takanori Uzawa
Biotechnology Letters 2015 Volume 37( Issue 3) pp:619-625
Publication Date(Web):2015 March
DOI:10.1007/s10529-014-1719-7
A peptide aptamer that changes fluorescence upon binding to verotoxin was selected in vitro using ribosome display with a tRNA carrying an environment-sensitive fluorescent probe. The aptamer specifically bound to verotoxin with a dissociation constant (Kd) of 3.94 ± 1.6 µM, and the fluorescence decreased by 78 % as the verotoxin concentration was increased. The selected peptide can be used for detection of verotoxin.
Co-reporter:Wei Wang, Takanori Uzawa, Naoya Tochio, Jumpei Hamatsu, Yoshinori Hirano, Seiichi Tada, Hisao Saneyoshi, Takanori Kigawa, Nobuhiro Hayashi, Yutaka Ito, Makoto Taiji, Toshiro Aigaki and Yoshihiro Ito
Chemical Communications 2014 vol. 50(Issue 22) pp:2962-2964
Publication Date(Web):18 Nov 2013
DOI:10.1039/C3CC47624C
A peptide that binds and emits fluorescence in response to conformational change in a target protein was developed by in vitro selection using tRNA carrying a fluorogenic amino acid. This technology could prove to be useful for the development of separation-free immunoassays and bio-imaging analyses.
Co-reporter:Hideto Maruyama, Yuko Nakashima, Satoshi Shuto, Akira Matsuda, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2014 vol. 50(Issue 11) pp:1284-1287
Publication Date(Web):29 Nov 2013
DOI:10.1039/C3CC47529H
Here we report a new strategy for the buildup reaction of active siRNA species from short RNA fragments in living cells using a chemical ligation reaction. This strategy could decrease undesired immune responses and provide more latitude for RNAi technology in the design and concentration of introduced RNA compared to traditional siRNA methods.
Co-reporter:Baiju G. Nair, Yukiko Nakano, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2014 vol. 50(Issue 5) pp:602-604
Publication Date(Web):04 Nov 2013
DOI:10.1039/C3CC45907A
Protein nanotubes formed by layer-by-layer (LbL) assembly can penetrate cells and act as nanopores for direct transmembrane delivery of chemical compounds.
Co-reporter:Hisao Saneyoshi, Tatsuya Ochikubo, Takushi Mashimo, Ken Hatano, Yoshihiro Ito, and Hiroshi Abe
Organic Letters 2014 Volume 16(Issue 1) pp:30-33
Publication Date(Web):December 3, 2013
DOI:10.1021/ol402832w
A series of triphenylphosphinecarboxamide (TPPc) derivatives were designed and synthesized as alternative reagents to triphenylphosphine for the facile reduction of azides. The TPPc derivatives performed as efficient reducing agents for the synthesis of primary amines without the need for an additional hydrolysis procedure. The TPPc derivatives were also applied to nucleic acid sensing using a RhAz-oligonucleotide conjugate in a DNA-templated fluorogenic reaction.
Co-reporter:Binata Joddar, Aydin Albayrak, Jeonghwa Kang, Mizuki Nishihara, Hiroshi Abe, Yoshihiro Ito
Acta Biomaterialia 2014 Volume 10(Issue 8) pp:3811
Publication Date(Web):August 2014
DOI:10.1016/j.actbio.2014.05.034
Co-reporter:Tetsuro Mazaki, Takashi Kitajima, Yasuyuki Shiozaki, Miwa Sato, Megumi Mino, Aki Yoshida, Mariko Nakamura, Yasuhiro Yoshida, Masato Tanaka, Toshifumi Ozaki, Akihiro Matsukawa, Yoshihiro Ito
Journal of Functional Foods 2014 Volume 6() pp:241-247
Publication Date(Web):January 2014
DOI:10.1016/j.jff.2013.10.013
Co-reporter:Binata Joddar, Takashi Hoshiba, Guoping Chen and Yoshihiro Ito
Biomaterials Science 2014 vol. 2(Issue 11) pp:1595-1603
Publication Date(Web):08 Aug 2014
DOI:10.1039/C4BM00126E
There have been great efforts to develop cell culture systems to regulate stem cell functions. Development of cell culture substrates is one of the important approaches for stem cell culture because substrates influence stem cell functions such as attachment, proliferation, self-renewal, and induction of differentiation. Stem cells are surrounded by their specific microenvironments in vivo, composed of cells, cytokines, and an extracellular matrix (ECM), which may dynamically change and affect cellular activities accordingly. To mimic such microenvironments, cell culture substrates can be prepared by coating bioactive proteins such as ECM proteins and signaling molecules as ligands for cell surface receptors. Compared with protein-coated substrates, cell- and cell-formed ECM-derived substrates have shown great progress and attracted significant attention as functional and prospective biomaterials for stem cell culture and regenerative medicine. In this review, we summarize the latest progress of these new substrates derived from cells and cell-formed ECMs.
Co-reporter:Wei Wang, Yoshinori Hirano, Takanori Uzawa, Mingzhe Liu, Makoto Taiji and Yoshihiro Ito
MedChemComm 2014 vol. 5(Issue 9) pp:1400-1403
Publication Date(Web):25 Jun 2014
DOI:10.1039/C4MD00142G
To increase the inhibitory activity of purvalanol against cyclin-dependent kinase 2, we increased the extent of interaction between the inhibitor and the target by coupling a peptide aptamer to purvalanol. The peptide–purvalanol conjugate, selected using a ribosome display, had a significantly enhanced inhibitory effect compared with purvalanol alone. The technique is useful as another type of fragment-based drug design tool.
Co-reporter:Shin-Hye Park;Liping Zhu;Seiichi Tada;Sei Obuse;Yasuhiro Yoshida;Mariko Nakamura;Tae Il Son;Satoshi Tsuneda
Polymer International 2014 Volume 63( Issue 9) pp:1616-1619
Publication Date(Web):
DOI:10.1002/pi.4647
Abstract
Phosphorylated gelatin was prepared for surface modification of titanium to enhance cell attachment. The modified gelatin was synthesized by coupling gelatin with phosphonobutyric acid with water-soluble carbodiimide. Circular dichroism revealed no significant change in the gelatin as a result of phosphorylation. The binding behavior of phosphorylated gelatin on the titanium surface was observed by quartz crystal microbalance. The modified titanium surface was analyzed by measuring the water contact angle. Enhancement of the attachment of osteoblast cells MC-3T3L1 was observed on the phosphorylated-gelatin-modified titanium. Phosphorylation of gelatin was effective for preparation of a cell-adhesive titanium surface. © 2013 Society of Chemical Industry
Co-reporter:Seiichi Tada, Emel Timucin, Takashi Kitajima, Osman U. Sezerman, Yoshihiro Ito
Biomaterials 2014 35(11) pp: 3497-3503
Publication Date(Web):
DOI:10.1016/j.biomaterials.2014.01.010
Co-reporter:Di Zhou
Science China Chemistry 2014 Volume 57( Issue 4) pp:510-521
Publication Date(Web):2014 April
DOI:10.1007/s11426-014-5069-z
Photocurable systems, which offer advantages such as microfabrication and in situ fabrication, have been widely used as dental restorative materials. Because the visible light-curable (VLC) system causes no biological damage, it is popular as a dental material and is being investigated by many researchers for other medical applications. Here, the principle of the VLC system is explained and recent progress in key components including photoinitiators, monomers, macromers, and prepolymers is discussed. Finally, biomedical applications for drug delivery and soft tissue engineering are reviewed. Considering the recent development of VLC systems, its importance in the field of medical applications is expected to continue to increase in the future.
Co-reporter:Hisao Saneyoshi ; Yoshihiro Ito ;Hiroshi Abe
Journal of the American Chemical Society 2013 Volume 135(Issue 37) pp:13632-13635
Publication Date(Web):September 6, 2013
DOI:10.1021/ja406724k
A pre-type sensitizer for a lanthanide complex on an oligonucleotide was successfully converted to a perfect final structure in a target DNA/RNA-templated reaction, without any chemical reagent or enzyme, under neutral conditions. The final form of the lanthanide–oligonucleotide provided a long-lived luminescence signal, appropriate for time-gated luminescence analysis and signal amplification. Target DNA/RNA-assisted time-gated luminescence analysis is a powerful tool for elimination of autofluorescence and detection of target RNA in living bacterial cells.
Co-reporter:Aya Shibata ; Takanori Uzawa ; Yuko Nakashima ; Mika Ito ; Yukiko Nakano ; Satoshi Shuto ; Yoshihiro Ito ;Hiroshi Abe
Journal of the American Chemical Society 2013 Volume 135(Issue 38) pp:14172-14178
Publication Date(Web):September 9, 2013
DOI:10.1021/ja404743m
Oligonucleotide-templated reactions are powerful tools for the detection of nucleic acid sequences. One of the major scientific challenges associated with this technique is the rational design of non-enzyme-mediated catalytic templated reactions capable of multiple turnovers that provide high levels of signal amplification. Herein, we report the development of a nucleophilic aromatic substitution reaction-triggered fluorescent probe. The probe underwent a rapid templated reaction without any of the undesired background reactions. The fluorogenic reaction conducted in the presence of a template provided a 223-fold increase in fluorescence after 30 s compared with the nontemplated reaction. The probe provided an efficient level of signal amplification that ultimately enabled particularly sensitive levels of detection. Assuming a simple model for the templated reactions, it was possible to estimate the rate constants of the chemical reaction in the presence and in the absence of the template. From these kinetic analyses, it was possible to confirm that an efficient turnover cycle had been achieved, on the basis of the dramatic enhancement in the rate of the chemical reaction considered to be the rate-determining step. With maximized turnover efficiency, it was demonstrated that the probe could offer a high turnover number of 1500 times to enable sensitive levels of detection with a detection limit of 0.5 pM in the catalytic templated reactions.
Co-reporter:Takanori Uzawa, Seiichi Tada, Wei Wang and Yoshihiro Ito
Chemical Communications 2013 vol. 49(Issue 18) pp:1786-1795
Publication Date(Web):02 Jan 2013
DOI:10.1039/C2CC36348H
The possibility of evolving a commonly existing biomolecule into a variety of functional biomolecules has now been realized in the form of aptamers through the development of in vitro selection. In addition to their high affinity and high specificity for the desired targets, aptamers are easily synthesized chemically and can be modified for downstream applications. Although aptamers were originally selected from a library containing only natural components, the past decade has seen a wealth of new aptamers selected from libraries containing unnatural components to provide new aptamer functions artificially. In this review, we highlight this transition (the shift between selection from natural components and selection from unnatural components) and the applications of selected aptamers.
Co-reporter:Aya Shibata, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2013 vol. 49(Issue 3) pp:270-272
Publication Date(Web):13 Nov 2012
DOI:10.1039/C2CC37826D
We have developed a system to release a biologically active molecule in response to the sequence of a target gene. The releasing system, which was triggered by the reduction of an azidomethyl group, was successfully applied to protein expression induced by the release of IPTG triggered by endogenous RNA in bacterial cells.
Co-reporter:Binata Joddar, Aydin Albayrak, Jeonghwa Kang, Mizuki Nishihara, Hiroshi Abe, Yoshihiro Ito
Acta Biomaterialia 2013 Volume 9(Issue 5) pp:6753-6761
Publication Date(Web):May 2013
DOI:10.1016/j.actbio.2013.01.007
Abstract
Dopamine, an adhesive protein can be covalently deposited onto biomaterials. In this study, we evaluated the ability of dopamine-coated surfaces for small interfering RNA (siRNA) immobilization and release. Dopamine was deposited onto 316L stainless steel discs either as a monolayer at acidic pH or as polydopamine at alkaline pH, following which siRNA was immobilized onto these discs. To investigate the RNA interference ability of immobilized siRNA, reduction of luciferase expression in HeLa, and reduction of Egr-1 expression and cell proliferation in human aortic smooth muscle cells (HAoSMCs) were determined. Dopamine treatment of 316L stainless steel discs under both the acidic and alkaline conditions resulted in the deposition of amino (NH2) groups, which enabled electrostatic immobilization of siRNA. The immobilized siRNA was released from both types of coatings, and enhanced the percent suppression of firefly luciferase activity of HeLa significantly up to ∼96.5% compared to HeLa on non-dopamine controls (18%). Both the release of siRNA and the percent suppression of firefly luciferase activity were sustained for at least 7 days. In another set of experiments, siRNA sequences targeting to inhibit the activity of the transcription factor Egr-1 were eluted from dopamine-coated surfaces to HAoSMCs. Egr-1 siRNA eluted from dopamine-coated surfaces, significantly reduced the proliferation of HAoSMCs and their protein expression of Egr-1. Therefore, this method of surface immobilization of siRNA onto dopamine-coated surfaces might be effective for nucleic acid delivery from stents.
Co-reporter:Aya Shibata, Yukiko Nakano, Mika Ito, Mika Araki, Jie Zhang, Yasuhiko Yoshida, Satoshi Shuto, Bengt Mannervik, Ralf Mogenstern, Yoshihiro Ito and Hiroshi Abe
Analyst 2013 vol. 138(Issue 24) pp:7326-7330
Publication Date(Web):08 Oct 2013
DOI:10.1039/C3AN01339A
We have synthesized a series of 4-substituted-2-nitrobenzene-sulfonyl compounds for caged fluorogenic probes and conducted a Hammett plot analysis using the steady-state kinetic parameters. The results revealed that the glutathione transferase (GST) alpha catalyzed reaction was dependent on the σ value in the same way as the non-enzymatic reaction, whereas the dependence of the σ value of the GST mu and pi was not as pronounced as that of GST alpha.
Co-reporter:Pallavi Ananda Kadengodlu, Toshiro Aigaki, Hiroshi Abe and Yoshihiro Ito
Molecular BioSystems 2013 vol. 9(Issue 5) pp:965-968
Publication Date(Web):21 Dec 2012
DOI:10.1039/C2MB25424G
Polymeric micelle prepared through the self-assembly of cationic cholesterol-modified gelatin was tested for siRNA delivery. It exerted the desired effect of gene knockdown in HeLa cells stably expressing the luciferase gene and achieved a two-fold increase in the knockdown ability when compared to Lipofectamine® 2000. It was found that the polymeric micelle exhibited excellent stability and increased the biological stability of the siRNA in serum.
Co-reporter:Di Zhou and Yoshihiro Ito
RSC Advances 2013 vol. 3(Issue 28) pp:11095-11106
Publication Date(Web):18 Jan 2013
DOI:10.1039/C3RA23313H
Medical and dental titanium has become the fundamental material in clinical use, in applications from surgical instruments and orthopedic rods to pins and plates. Besides titanium, various inorganic materials have been used in tissue engineering because of their unique mechanical properties. However, inorganic materials have no specific biological activities. The immobilization of growth factors on these materials is expected to add various biological functionalities that can regulate cell destinies, including not only adhesion but also cell growth or differentiation at the interface between these inorganic materials and biological tissues. This review discusses recent progress in the immobilization of growth factors on inorganic materials, including the methods and applications used for hard tissue engineering.
Co-reporter:Hisao Saneyoshi, Takushi Mashimo, Ken Hatano, Yoshihiro Ito, Hiroshi Abe
Tetrahedron Letters 2013 Volume 54(Issue 9) pp:1080-1083
Publication Date(Web):27 February 2013
DOI:10.1016/j.tetlet.2012.12.028
We have synthesized a 2′-aminomethyl branched-chain sugar nucleoside phosphorodithioate from 2,2′-anhydro uridine and subjected the material to a subsequent cyclization reaction under aqueous conditions using bi-functional linkers. The rate of the cyclization reaction was dependent on the leaving group on the bi-functional linkers. The generation of a chiral phosphorous peak from the achiral precursor, as indicated by 31P NMR, was identified as a good indicator for potentially probing the local and global features of the DNA structure.
Co-reporter:Zha Li;Takanori Uzawa;Takashi Tanaka;Akira Hida;Koji Ishibashi
Biotechnology Letters 2013 Volume 35( Issue 1) pp:39-45
Publication Date(Web):2013 January
DOI:10.1007/s10529-012-1049-6
A ribosome display from a diverse random library was applied for selecting peptide aptamers with high binding affinity to single-wall carbon nanotubes (SWCNTs). The selected peptide aptamer bound to and solubilized SWCNTs more strongly than did the peptide aptamer selected by a phage display method reported previously, and more strongly than other commonly used organic surfactants. The fluorescence spectrum of this aptamer showed a red shift upon interaction with SWCNTs but circular dichroism spectroscopy did not show any significant difference between the presence or absence of SWCNT binding.
Co-reporter:Naoko Abe;Dr. Michio Hiroshima;Hideto Maruyama;Dr. Yuko Nakashima;Dr. Yukiko Nakano;Dr. Akira Matsuda;Dr. Yasushi Sako;Dr. Yoshihiro Ito;Dr. Hiroshi Abe
Angewandte Chemie 2013 Volume 125( Issue 27) pp:7142-7146
Publication Date(Web):
DOI:10.1002/ange.201302044
Co-reporter:Binata Joddar, Adam T. Guy, Hiroyuki Kamiguchi, Yoshihiro Ito
Biomaterials 2013 34(37) pp: 9593-9601
Publication Date(Web):
DOI:10.1016/j.biomaterials.2013.08.019
Co-reporter:Yoshihiro Ito, Seiichi Tada
Biomaterials 2013 34(31) pp: 7565-7574
Publication Date(Web):
DOI:10.1016/j.biomaterials.2013.06.037
Co-reporter:Jeonghwa Kang, Seiichi Tada, Makoto Sakuragi, Hiroshi Abe, Reiko Ito, Junko Ishikawa, Shino Kurata, Takashi Kitajima, Tae Il Son, Toshiro Aigaki, Yoshihiro Ito
Biomaterials 2013 34(38) pp: 9747-9753
Publication Date(Web):
DOI:10.1016/j.biomaterials.2013.09.004
Co-reporter:Naoko Abe;Dr. Michio Hiroshima;Hideto Maruyama;Dr. Yuko Nakashima;Dr. Yukiko Nakano;Dr. Akira Matsuda;Dr. Yasushi Sako;Dr. Yoshihiro Ito;Dr. Hiroshi Abe
Angewandte Chemie International Edition 2013 Volume 52( Issue 27) pp:7004-7008
Publication Date(Web):
DOI:10.1002/anie.201302044
Co-reporter:Mingzhe Liu, Seiichi Tada, Mika Ito, Hiroshi Abe and Yoshihiro Ito
Chemical Communications 2012 vol. 48(Issue 97) pp:11871-11873
Publication Date(Web):17 Oct 2012
DOI:10.1039/C2CC36618E
A photo-responsive peptide aptamer against microbeads immobilized streptavidin was isolated using in vitro selection combined with photo-manipulation. This is the first example of the introduction of a peptide aptamer in the photo-control of dynamic molecular recognition.
Co-reporter:Yasutsugu Tamura, Kazuhiro Furukawa, Rei Yoshimoto, Yuto Kawai, Minoru Yoshida, Satoshi Tsuneda, Yoshihiro Ito, Hiroshi Abe
Bioorganic & Medicinal Chemistry Letters 2012 Volume 22(Issue 23) pp:7248-7251
Publication Date(Web):1 December 2012
DOI:10.1016/j.bmcl.2012.09.033
RNA splicing is an important target for basic research of disease mechanisms and for drug discovery. Here, we report a new method for analysis of the in vitro RNA splicing process that produces fluorescence using a reduction-triggered fluorescence (RETF) probe. The fluorescence signal is produced only when the two probes bind side-by-side with a specific RNA target. Precursor messenger RNA and mature messenger RNA originating from the chicken δ-crystallin (CDC) gene were successfully discriminated in solution using an RETF probe with the assistance of helper oligonucleotide strands. Also, we successfully applied RETF probes to the detection of emerging mature mRNA in an in vitro splicing process.
Co-reporter:Jeonghwa Kang, Makoto Sakuragi, Aya Shibata, Hiroshi Abe, Takashi Kitajima, Seiichi Tada, Masayoshi Mizutani, Hitoshi Ohmori, Hirohito Ayame, Tae Il Son, Toshiro Aigaki, Yoshihiro Ito
Materials Science and Engineering: C 2012 Volume 32(Issue 8) pp:2552-2561
Publication Date(Web):1 December 2012
DOI:10.1016/j.msec.2012.07.039
Titanium and stainless steel were modified with dopamine for the immobilization of biomolecules, epidermal growth factor (EGF). First, the treatment of metal surfaces with a dopamine solution under different pH conditions was investigated. At higher pH, the dopamine solution turned brown and formed precipitates. Treatment of the metals with dopamine at pH 8.5 also resulted in the development of brown color at the surface of the metals. The hydrophobicity of the surfaces increased after treatment with dopamine, independently of pH. X-ray photoelectron spectroscopy revealed the formation of a significant amount of an organic layer on both surfaces at pH 8.5. According to ellipsometry measurements, the organic layer formed at pH 8.5 was about 1000 times as thick as that formed at pH 4.5. The amount of amino groups in the layer formed at pH 8.5 was also higher than that observed in the layer formed at pH 4.5. EGF molecules were immobilized onto the dopamine-treated surfaces via a coupling reaction using carbodiimide. A greater amount of EGF was immobilized on surfaces treated at pH 8.5 compared with pH 4.5. Significantly higher growth of rat fibroblast cells was observed on the two EGF-immobilized surfaces compared with non-immobilized surfaces in the presence of EGF. The present study demonstrated that metals can become bioactive via the surface immobilization of a growth factor and that the effect of the immobilized growth factor on metals was greater than that of soluble growth factor.Highlights► Epidermal growth factor was covalently immobilized on titan or stainless steel surfaces. ► Amino groups were formed on the surfaces by the treatment and the growth factor was immobilized through amide bonds. ► The immobilized epidermal growth factor accelerated cell proliferation more than soluble ones on the surfaces.
Co-reporter:Dr. Yoshihiro Ito
ChemBioChem 2012 Volume 13( Issue 8) pp:1100-1102
Publication Date(Web):
DOI:10.1002/cbic.201200183
Co-reporter:Dr. Hiroshi Abe;Naoko Abe;Dr. Aya Shibata;Keiji Ito;Dr. Yoshiyuki Tanaka;Mika Ito;Dr. Hisao Saneyoshi;Dr. Satoshi Shuto;Dr. Yoshihiro Ito
Angewandte Chemie International Edition 2012 Volume 51( Issue 26) pp:6475-6479
Publication Date(Web):
DOI:10.1002/anie.201201111
Co-reporter:Hongxu Lu, Naoki Kawazoe, Takashi Kitajima, Yuka Myoken, Masahiro Tomita, Akihiro Umezawa, Guoping Chen, Yoshihiro Ito
Biomaterials 2012 33(26) pp: 6140-6146
Publication Date(Web):
DOI:10.1016/j.biomaterials.2012.05.038
Co-reporter:Binata Joddar and Yoshihiro Ito
Journal of Materials Chemistry A 2011 vol. 21(Issue 36) pp:13737-13755
Publication Date(Web):28 Jul 2011
DOI:10.1039/C1JM10984G
It is very important to modify the surfaces of biomaterials for regulation of cells in the development of regenerative medicine or tissue engineering. Biomaterials are categorized into three primary types, metallic, ceramic, and polymers. Here the biological modification of biomaterial surfaces such as metals, ceramics, and polymers and the effects of such biological modifications are discussed. It is well known that cellular compatibility is regulated by three interactions: one is with extracellular matrices (ECM), second with neighboring cells, and third with soluble biosignals such as growth factors. Biomaterial researchers have immobilized ECM, cell adhesion factors, and growth factors on various materials to regulate cellular functions. Herein, biosignaling of ECM, cell adhesion factors, and growth factors are reviewed and biomaterial designs to activate biosignaling mechanisms are discussed.
Co-reporter:Naoko Abe, Hiroshi Abe, Takahito Ohshiro, Yuko Nakashima, Mizuo Maeda and Yoshihiro Ito
Chemical Communications 2011 vol. 47(Issue 7) pp:2125-2127
Publication Date(Web):21 Dec 2010
DOI:10.1039/C0CC04551A
Small circular double-stranded RNAs (dsRNAs) were synthesized. The structural analysis by atomic force microscopy gave direct images for the interpretation of the structural strain present in circular dsRNAs. Finally, we demonstrated that circular dsRNA caused RNAi effect in cells.
Co-reporter:Yuko Nakashima, Hiroshi Abe, Naoko Abe, Kyoko Aikawa and Yoshihiro Ito
Chemical Communications 2011 vol. 47(Issue 29) pp:8367-8369
Publication Date(Web):21 Jun 2011
DOI:10.1039/C1CC11780G
Branched RNAs with three- or four-way junctions were designed by assembling single-stranded RNA for RNA interference. Human Dicer transformed branched RNAs into about 20 base pairs of double-stranded RNA, which is a standard siRNA species. Our tetramer design provides a potent silencing effect over a period of 5 days.
Co-reporter:Naoko Abe, Hiroshi Abe, Chisato Nagai, Mitsuru Harada, Hiroto Hatakeyama, Hideyoshi Harashima, Takahito Ohshiro, Mizuki Nishihara, Kazuhiro Furukawa, Mizuo Maeda, Satoshi Tsuneda, and Yoshihiro Ito
Bioconjugate Chemistry 2011 Volume 22(Issue 10) pp:2082
Publication Date(Web):September 7, 2011
DOI:10.1021/bc2003154
RNA interference (RNAi) is one of the most promising new approaches for disease therapy. The design of a dumbbell-shaped nanocircular RNA allows it to act as a short interfering RNA (siRNA) precursor. To optimize the design, we studied the relationship between the nanostructure and RNAi activity by synthesizing various RNA dumbbells. An RNA dumbbell with a 23-bp stem and 9-nt loops was the most potent. Sequence analysis by mass spectrometry showed that Dicer could edit RNA dumbbells to siRNA species. The reaction offered the slow release of siRNA species, which conferred prolonged RNAi activity. Introduction of DNA into the loop position significantly stabilized the dumbbell in biological fluid without any loss of RNAi activity. In-depth pharmacological evaluation was performed by introducing dumbbells into HeLa cells that stably express the target luciferase gene. The dumbbells provided a rapid silencing effect and retained this effect for a longer time even at a lower concentration than that at which standard siRNA completely lost RNAi activity. We conclude that an RNA dumbbell with DNA loops is the most promising design for in vivo applications for RNA medicine.
Co-reporter:Dr. Kazuhiro Furukawa;Dr. Hiroshi Abe;Yasutsugu Tamura;Dr. Rei Yoshimoto;Dr. Minoru Yoshida;Dr. Satoshi Tsuneda;Dr. Yoshihiro Ito
Angewandte Chemie International Edition 2011 Volume 50( Issue 50) pp:12020-12023
Publication Date(Web):
DOI:10.1002/anie.201104425
Co-reporter:Binata Joddar, Takashi Kitajima, Yoshihiro Ito
Biomaterials 2011 32(33) pp: 8404-8415
Publication Date(Web):
DOI:10.1016/j.biomaterials.2011.07.083
Co-reporter:Tae Il Son, Makoto Sakuragi, Sawa Takahashi, Sei Obuse, Jeonghwa Kang, Masako Fujishiro, Haruhiko Matsushita, Jiansheng Gong, Shigeru Shimizu, Yusuke Tajima, Yasuhiro Yoshida, Kazuomi Suzuki, Toshio Yamamoto, Mariko Nakamura, Yoshihiro Ito
Acta Biomaterialia 2010 Volume 6(Issue 10) pp:4005-4010
Publication Date(Web):October 2010
DOI:10.1016/j.actbio.2010.05.018
Abstract
A novel visible light-crosslinkable porcine gelatin was prepared for gelation and micropatterning. The preparation employed a photo-oxidation-induced crosslinking mechanism. First, furfuryl groups were incorporated into the gelatin. Second, the modified gelatin was mixed in water with Rose Bengal, which is a visible light sensitizer. Irradiation by visible light solidified the aqueous solution. In addition, when the solution was cast on a plate, dried and photo-irradiated in the presence of a photomask a micropattern was formed that matched the micropattern on the photomask. The gelatin-immobilized regions enhanced cell adhesion. It was also confirmed that the gelatin incorporating furfuryl and Rose Bengal have no significant toxicity. The photo-crosslinkable gelatin was employed as a direct pulp capping material in the dental field. Considering these results, this system could be useful as a new type of visible light-induced crosslinkable biosealant.
Co-reporter:Kazuhiro Furukawa, Hiroshi Abe, Satoshi Tsuneda and Yoshihiro Ito
Organic & Biomolecular Chemistry 2010 vol. 8(Issue 10) pp:2309-2311
Publication Date(Web):15 Mar 2010
DOI:10.1039/B926100A
A new photocaged fluorescent compound, azidomethyl fluorescein, was successfully utilized to monitor the dynamics of oligonucleotides in living human cells.
Co-reporter:Mingzhe Liu, Hiroshi Jinmei, Hiroshi Abe, Yoshihiro Ito
Bioorganic & Medicinal Chemistry Letters 2010 Volume 20(Issue 9) pp:2964-2967
Publication Date(Web):1 May 2010
DOI:10.1016/j.bmcl.2010.02.109
A photoresponsive RNA aptamer to hemin was selected in vitro from a random sequence library of RNAs with azobenzene residues. The aptamer bound to hemin under visible light irradiation and was released by ultraviolet light.In vitro selection of photoresponsive RNA aptamer against hemin was reported.
Co-reporter:Makoto Sakuragi, Saki Tsuzuki, Sei Obuse, Akira Wada, Kenji Matoba, Izumi Kubo, Yoshihiro Ito
Materials Science and Engineering: C 2010 30(2) pp: 316-322
Publication Date(Web):
DOI:10.1016/j.msec.2009.11.006
Co-reporter:Aya Shibata, Hiroshi Abe, Mika Ito, Yuko Kondo, Shigeru Shimizu, Kyoko Aikawa and Yoshihiro Ito
Chemical Communications 2009 (Issue 43) pp:6586-6588
Publication Date(Web):05 Oct 2009
DOI:10.1039/B912896D
We have developed an SNAr reaction-triggered fluorescence probe using a new fluorogenic compound derivatized from 7-aminocoumarin for oligonucleotides detection.
Co-reporter:Kazuhiro Furukawa, Hiroshi Abe, Kayo Hibino, Yasushi Sako, Satoshi Tsuneda and Yoshihiro Ito
Bioconjugate Chemistry 2009 Volume 20(Issue 5) pp:1026
Publication Date(Web):April 17, 2009
DOI:10.1021/bc900040t
Oligonucleotide-templated reactions are attracting attention as a method for RNA detection in living cells. Previously, a reduction-triggered fluorescence probe has been reported that is based on azide reduction to switch fluorescence on. In this article, we report a more advanced probe, a reduction-triggered fluorescent amplification probe that is capable of amplifying a target signal. Azidomethyl fluorescein was newly synthesized and introduced into a probe. Azido-masked fluorescein on the probe showed a strong turn-on fluorescence signal upon oligonucleotide-templated Staudinger reduction. The catalytic reaction of the probe offered a turnover number of 50 as fluorescence readout within 4 h. Finally, probes were introduced into human leukemia HL-60 cells by use of streptolysin O pore-forming peptide. We successfully detected and quantitated the 28S rRNA and β-Actin mRNA signal above the background by flow cytometry. In addition, the same RNA targets were imaged by fluorescence microscopy. The data suggest that a reduction-triggered amplification probe may be a powerful tool in analyzing the localization, transcription, or processing of RNA species in living eukaryotic cells.
Co-reporter:Xian Jun Loh, Wun Chet Davy Cheong, Jun Li and Yoshihiro Ito
Soft Matter 2009 vol. 5(Issue 15) pp:2937-2946
Publication Date(Web):12 Jun 2009
DOI:10.1039/B904171K
A thermoresponsive surface was fabricated by coating a substrate with a thermoresponsive amphiphilic triblock copolymer, poly(N-isopropylacrylamide)-poly[(R)-3-hydroxybutyrate]-poly(N-isopropylacrylamide) (PNIPAAm-PHB-PNIPAAm), and used for the attachment and nonenzymatic temperature-induced detachment of human mesenchymal stem cells. The copolymer self-assembled into micelles in water and formed stable attachments to the substrate by hydrophobic interactions between the micelle core and the substrate surface. The stability of the polymer attachment was confirmed by ATR-FTIR analysis of the polymer-coated substrates before and after soaking in water. Illustration of the copolymer coating on the cell culture substrate was accomplished by applying Farago's implicit-solvent model for studying the self-assembly of large molecules. The copolymer coating enhanced the proliferation of human mesenchymal stem cells compared with either PNIPAAm homopolymer-coated or noncoated surface. The copolymer-coated substrate showed a change in the surface hydrophilicity when the temperature was changed. After a period of culture, the cells could be detached by cooling at 4 °C for 20 min without trypsin treatment.
Co-reporter:Xian Jun Loh;Jiansheng Gong;Makoto Sakuragi;Takashi Kitajima;Mingzhe Liu;Jun Li
Macromolecular Bioscience 2009 Volume 9( Issue 11) pp:1069-1079
Publication Date(Web):
DOI:10.1002/mabi.200900081
Co-reporter:Kazuhiro Furukawa, Hiroshi Abe, Jin Wang, Miwako Uda, Hiroyuki Koshino, Satoshi Tsuneda and Yoshihiro Ito
Organic & Biomolecular Chemistry 2009 vol. 7(Issue 4) pp:671-677
Publication Date(Web):12 Dec 2008
DOI:10.1039/B817228E
We have developed a new red fluorogenic compound derived from naphthorhodamine for a reduction-triggered fluorescence probe to sense oligonucleotides. The fluorogenic reaction between naphthorhodamine azide derivatives and reducing reagents such as triphenylphosphine (TPP) on the DNA target does not use any enzyme or reagent, and fluoresces at 650 nm. The probes were used for dual color detection of a single nucleotide difference on the leukemia-related bcr/abl gene.
Co-reporter:Makoto Sakuragi;Saki Tsuzuki;Hirokazu Hasuda;Akira Wada;Kenji Matoba;Izumi Kubo
Journal of Applied Polymer Science 2009 Volume 112( Issue 1) pp:315-319
Publication Date(Web):
DOI:10.1002/app.29427
Abstract
A novel photoreactive polymer with histidine polar groups was synthesized through the copolymerization of two types of methacrylic acid, one carrying histidine groups and the other carrying azidoaniline groups. The polymer was photoimmobilized on polyester disks for surface modification. The effect of the surface modification on the hydrophilic and biofouling properties was investigated. Static contact angle measurements showed that the polymeric surface was modified to be comparatively hydrophilic in the polymer-immobilized region. Micropattern immobilization was carried out with a photolithographic method. Atomic force microscopy measurements showed that the polymer was formed on the disks in response to ultraviolet irradiation. Protein adsorption was reduced on the polymer-immobilized regions, and in those regions, spreading and adhesion of mammalian cells were reduced in comparison with that in nonimmobilized regions. In conclusion, a novel histidine-containing polymer was photoreactively immobilized on a conventional polymer surface, and it had reduced interaction with proteins and cells. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Mingzhe Liu, Takuma Kagahara, Hiroshi Abe, Yoshihiro Ito
Bioorganic & Medicinal Chemistry Letters 2009 19(5) pp: 1484-1487
Publication Date(Web):
DOI:10.1016/j.bmcl.2009.01.016
Co-reporter:Hiroshi Abe, Yuko Kondo, Hiroshi Jinmei, Naoko Abe, Kazuhiro Furukawa, Atsushi Uchiyama, Satoshi Tsuneda, Kyoko Aikawa, Isamu Matsumoto and Yoshihiro Ito
Bioconjugate Chemistry 2008 Volume 19(Issue 1) pp:327
Publication Date(Web):November 9, 2007
DOI:10.1021/bc700244s
Enzymatic ligation methods are useful in the diagnostic detection of DNA sequences. Here, we describe the investigation of nonenzymatic phosphorothioate−iodoacetyl DNA chemical ligation as a method for the detection and identification of RNA and DNA. The specificity of ligation on the DNA target is shown to allow the discrimination of a single point mutation with a drop in the ligation yield of up to 16.1-fold. Although enzymatic ligation has very low activity for RNA targets, this reaction is very efficient for RNA targets. The speed of the chemical ligation with an RNA target achieves a 70% yield in 5 s, which is equal to or better than that of ligase-enzyme-mediated ligation with a DNA target. The reaction also exhibits a significant level of signal amplification under thermal cycling in periods as short as 100–120 min, with the RNA or DNA target acting in a catalytic way to ligate multiple pairs of probes.
Co-reporter:Hiroshi Abe, Jin Wang, Kazuhiro Furukawa, Kazuma Oki, Miwako Uda, Satoshi Tsuneda and Yoshihiro Ito
Bioconjugate Chemistry 2008 Volume 19(Issue 6) pp:1219
Publication Date(Web):May 14, 2008
DOI:10.1021/bc800014d
We have developed a reduction-triggered fluorescence probe with a new fluorogenic compound derivatized from Rhodamine for sensing oligonucleotides. The chemistry to activate the compound involves the reaction between the azide group of rhodamine derivatives and the reducing reagents, with the fluorescence signal appearing after reduction of the azide group. The signal/background ratio of this fluorogenic compound reached 2100-fold enhancement in fluorescence intensity. Dithio-1,4-threitol or triphenylphosphine as reducing reagents were successfully utilized for this chemistry to be introduced into the DNA probe. The genetic detection requires that two strands of DNA bind onto target oligonucleotides, one probe carrying a reducible fluorogenic compound while the other carries the reducing reagents. The reaction proceeds automatically without any enzymes or reagents under biological conditions to produce a fluorescence signal within 10−20 min in the presence of target DNA or RNA. In addition, the probe was very stable under biological conditions, even such extreme conditions as pH 5 solution, pH 10 solution, or high temperature (90 °C) with no undesirable background signal. The probes were successfully applied to the detection of oligonucleotides at the single nucleotide level in solution and endogenous RNA in bacterial cells.
Co-reporter:Jiansheng Gong
Cytotechnology 2008 Volume 58( Issue 3) pp:141-144
Publication Date(Web):2008 November
DOI:10.1007/s10616-008-9179-3
A multivalent ligand of thrombopoietin (TPO) was prepared by immobilization of mimetic peptides on gold particles. An effective peptide ligand containing cysteine was designed to enhance the growth of TPO-sensitive cells. The peptide was then immobilized on gold particles by self assembly. The multivalent ligand enhanced the growth of TPO-dependent cells and its activity was more than that of the monovalent ligand.
Co-reporter:Yoshihiro Ito, Hirokazu Hasuda, Makoto Sakuragi, Saki Tsuzuki
Acta Biomaterialia 2007 Volume 3(Issue 6) pp:1024-1032
Publication Date(Web):November 2007
DOI:10.1016/j.actbio.2007.05.010
Abstract
Photoreactive poly(ethylene glycol) (PEG) was prepared and the polymer was photoimmobilized on organic, inorganic and metal surfaces to reduce their interaction with proteins and cells. The photoreactive PEG was synthesized by co-polymerization of methacrylate-PEG and acryloyl 4-azidobenzene. Surface modification was carried in the presence and the absence of a micropatterned photomask. It was then straightforward to confirm the immobilization using the micropatterning. Using the micropatterning method, immobilization of the photoreactive PEG on plastic (Thermanox™), glass and titanium was confirmed by time-of-flight secondary ion mass spectroscopy and atomic force microscopy observations. The contact angle on an unpatterned surface was measured. Although the original surfaces have different contact angles, the contact angle on PEG-immobilized surfaces was the same on all surfaces. This result demonstrated that the surface was completely covered with PEG by the photoimmobilization. To assess non-specific protein adsorption on the micropatterned surface, horseradish peroxidase (HRP)-conjugated proteins were adsorbed. Reduced protein adsorption was confirmed by vanishingly small staining of HRP substrates on the immobilized regions. COS-7 cells were cultured on the micropatterned surface. The cells did not adhere to the PEG-coated regions. In conclusion, photoreactive PEG was immobilized on various surfaces and tended to reduce interactions with proteins and cells.
Co-reporter:Mojgan Heydari;Makoto Sakuragi;Hirokazu Hasuda;Yasuhiro Yoshida;Kazuomi Suzuki
Journal of Biomedical Materials Research Part A 2007 Volume 83A(Issue 4) pp:906-914
Publication Date(Web):13 JUN 2007
DOI:10.1002/jbm.a.31368
Titan (TiO2) was modified with photoreactive gelatin in order to regulate the attachment of cells. Photoreactive gelatin, which was synthesized by the coupling reaction of gelatin with N-(4-azidobenzoyloxy) succinimide, was immobilized onto the n-octadecyltrimethoxysilane (ODS)-TiO2 or TiO2 surface by ultraviolet irradiation both in the absence and presence of a photo mask. In the absence of a photo mask, the modified titan surface was analyzed by measuring water contact angles and X-ray photoelectron spectroscopy (XPS). The result showed that ODS hydrophobilized the titan surface, and that the immobilization of gelatin affected the surface's hydrophilicity. XPS shows that titan was covered with organic material, including ODS and gelatin. With the photo mask in place, micropatterning of the gelatin was performed. This pattern was confirmed by optical microscopy and time-of-flight secondary ion-mass spectroscopy (TOF-SIMS). Monkey COS-7 epithelial cells were cultured on the unpattern- and pattern-immobilized plate. A significantly higher degree of cell attachment was found on the photoreactive gelatin-immobilized regions than on those that were not immobilized. It was concluded that the cellular pattern on titan was regulated by immobilized photoreactive gelatin. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Co-reporter:Wei Wang, Shuta Hara, Mingzhe Liu, Toshiro Aigaki, ... Yoshihiro Ito
Journal of Bioscience and Bioengineering (November 2011) Volume 112(Issue 5) pp:515-517
Publication Date(Web):1 November 2011
DOI:10.1016/j.jbiosc.2011.07.011
A newly developed ribosome display protocol was applied to the in vitro selection of polypeptide aptamers to small molecular weight chemicals, 6-[hydroxy(4-nitrobenzyl)phosphonyl]hexanoic acid and vitamin B12, chosen from a peptide library of random sequences. New peptide sequences binding to the targets were found after six rounds of this protocol.
Co-reporter:Mingzhe Liu, Muye Xu, Xian Jun Loh, Hiroshi Abe, ... Yoshihiro Ito
Journal of Bioscience and Bioengineering (May 2011) Volume 111(Issue 5) pp:564-568
Publication Date(Web):1 May 2011
DOI:10.1016/j.jbiosc.2011.01.001
Antibodies were covalently conjugated with poly(ethylene glycol) (PEG) and the properties of the PEGylated antibodies in organic media were investigated. Two types of monoclonal antibody were used in this study. One was a monoclonal antibody (abzyme) that was prepared against a hapten mimicking a transition state of hydrolysis. Another was a monoclonal antibody against estrogen, which is not soluble in water. By electrophoresis and mass spectral analysis, the covalent conjugation with PEG chains was confirmed. The PEGylated antibodies bound to antigens and the PEGylated abzyme catalyzed a hydrolysis reaction in an aqueous solution. The PEGylated antibodies were soluble in dichloromethane and acetone and interacted with antigen either in dichloromethane or in acetone. In conclusion, PEGylated antibodies can be employed as analytical tools for water-insoluble analytes.
Co-reporter:Yoshihiro Ito, Nozomi Moritsugu, Takahisa Matsue, Kiyomi Mitsukoshi, Hirohito Ayame, Norihiko Okochi, Hideshi Hattori, Hideo Tashiro, Sakura Sato, Motohiro Ebisawa
Journal of Biotechnology (15 November 2012) Volume 161(Issue 4) pp:414-421
Publication Date(Web):15 November 2012
DOI:10.1016/j.jbiotec.2012.07.196
An automated microarray diagnostic system for specific IgE using photoimmobilized allergen has been developed. Photoimmobilization is useful for preparing microarrays, where various types of biological components are covalently immobilized on a plate. Because the immobilization is based on a photo-induced radical cross-linking reaction, it does not require specific functional groups on the immobilized components. Here, an aqueous solution of a photoreactive poly(ethylene glycol)-based polymer was spin-coated on a plate, and an aqueous solution of each allergen was microspotted on the coated plate and allowed to dry in air. Finally, the plate was irradiated with an ultraviolet lamp for covalent immobilization. An automated machine using these plates was developed for the assay of antigen-specific IgE. Initially, the patient serum was added to the microarray plate, and after reaction of the microspotted allergen with IgE, the adsorbed IgE was detected by a peroxidase-conjugated anti-IgE-antibody. The chemical luminescence intensity of the substrate decomposed by the peroxidase was automatically detected using a sensitive charge-coupled device camera. All the allergens were immobilized stably using this method, which was used to screen for allergen-specific IgE. The results were comparable with those using conventional specific IgE. Using this system, six different allergen-specific IgE were assayed using 10 μL of serum within a period of 20 min.Highlights► An automated microarray diagnostic system for specific IgE was developed. ► Photoimmobilization was employed for preparing the microarrays. ► All the allergens were immobilized stably and used to screen for allergen-specific IgE. ► Six allergen-specific IgEs were assayed using 10 μL of serum during 20 min.
Co-reporter:Kazuhiro Furukawa, Hiroshi Abe, Satoshi Tsuneda and Yoshihiro Ito
Organic & Biomolecular Chemistry 2010 - vol. 8(Issue 10) pp:NaN2311-2311
Publication Date(Web):2010/03/15
DOI:10.1039/B926100A
A new photocaged fluorescent compound, azidomethyl fluorescein, was successfully utilized to monitor the dynamics of oligonucleotides in living human cells.
Co-reporter:Siyoong Seo, Kazumitsu Onizuka, Chieko Nishioka, Eiki Takahashi, Satoshi Tsuneda, Hiroshi Abe and Yoshihiro Ito
Organic & Biomolecular Chemistry 2015 - vol. 13(Issue 15) pp:NaN4595-4595
Publication Date(Web):2015/03/06
DOI:10.1039/C5OB00199D
The representative DNA-labeling agent 5-ethynyl-2′-deoxyuridine (EdU) was chemically modified to improve its function. Chemical monophosphorylation was expected to enhance the efficiency of the substrate in DNA polymerization by circumventing the enzymatic monophosphorylation step that consumes energy. In addition, to enhance cell permeability, the phosphates were protected with bis-pivaloyloxymethyl that is stable in buffer and plasma, and degradable inside various cell types. The phosphorylated EdU (PEdU) was less toxic than EdU, and had the same or a slightly higher DNA-labeling ability in vitro. PEdU was also successfully applied to DNA labeling in vivo. In conclusion, PEdU can be used as a less toxic DNA-labeling agent for studies that require long-term cell survival or very sensitive cell lines.
Co-reporter:Mingzhe Liu, Seiichi Tada, Mika Ito, Hiroshi Abe and Yoshihiro Ito
Chemical Communications 2012 - vol. 48(Issue 97) pp:NaN11873-11873
Publication Date(Web):2012/10/17
DOI:10.1039/C2CC36618E
A photo-responsive peptide aptamer against microbeads immobilized streptavidin was isolated using in vitro selection combined with photo-manipulation. This is the first example of the introduction of a peptide aptamer in the photo-control of dynamic molecular recognition.
Co-reporter:Yuko Nakashima, Hiroshi Abe, Naoko Abe, Kyoko Aikawa and Yoshihiro Ito
Chemical Communications 2011 - vol. 47(Issue 29) pp:NaN8369-8369
Publication Date(Web):2011/06/21
DOI:10.1039/C1CC11780G
Branched RNAs with three- or four-way junctions were designed by assembling single-stranded RNA for RNA interference. Human Dicer transformed branched RNAs into about 20 base pairs of double-stranded RNA, which is a standard siRNA species. Our tetramer design provides a potent silencing effect over a period of 5 days.
Co-reporter:Hideto Maruyama, Yuko Nakashima, Satoshi Shuto, Akira Matsuda, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2014 - vol. 50(Issue 11) pp:NaN1287-1287
Publication Date(Web):2013/11/29
DOI:10.1039/C3CC47529H
Here we report a new strategy for the buildup reaction of active siRNA species from short RNA fragments in living cells using a chemical ligation reaction. This strategy could decrease undesired immune responses and provide more latitude for RNAi technology in the design and concentration of introduced RNA compared to traditional siRNA methods.
Co-reporter:Baiju G. Nair, Yue Zhou, Kyoji Hagiwara, Masashi Ueki, Takashi Isoshima, Hiroshi Abe and Yoshihiro Ito
Journal of Materials Chemistry A 2017 - vol. 5(Issue 22) pp:NaN4051-4051
Publication Date(Web):2017/05/18
DOI:10.1039/C7TB00846E
Nanostructured RNA carrying three different siRNAs was assembled to silence three target genes (Axin, APC, and GSK-3β) in the Wnt/β-catenin signaling pathway. The trimer RNA nanostructure included equimolar concentrations of three oligonucleotide sequences. The three armed structures and the size of the trimer RNA were confirmed by agarose gel electrophoresis, atomic force microscopy, and dynamic light scattering. In the presence of 10% human serum, the trimer RNA was able to resist degradation and maintained an intact structure for more than two hours. Protein expression analyses showed specific repression of the target proteins by siRNAs. As a result, the expression of luciferase in a β-catenin reporter vector was significantly increased by the trimer RNA compared with a pool of the three individual siRNAs. This high activity at a low concentration was considered to be due to the 3-in-1 format of the trimer and the long-term resistance to serum proteins by nanostructure formation. We demonstrated that a nanostructured “3-in-1” siRNA is effective in enhancing the effect of RNA interference.
Co-reporter:Hongli Mao, Seong Min Kim, Masashi Ueki and Yoshihiro Ito
Journal of Materials Chemistry A 2017 - vol. 5(Issue 5) pp:NaN934-934
Publication Date(Web):2016/12/12
DOI:10.1039/C6TB02867E
In vitro expansion of human mesenchymal stem cells (hMSCs) using serum-free culture medium is important for basic research and clinical applications. It is known that some growth factors are required for developing a defined medium for hMSC culture. However, growth factors usually show poor stability, short circulating half-life and a rapid rate of cellular internalization when they are in a diffusible state. A potential way to overcome these problems is to immobilize growth factors on materials. Here, three different types of growth factors, basic fibroblast growth factor, transforming growth factor-beta, and platelet-derived growth factor, were co-immobilized on cell culture dish surfaces by photo-reactive gelatin and used for serum-free hMSC cultures. The results showed that the immobilized growth factors supported cell proliferation similarly to the serum-containing medium. More importantly, the immobilization of growth factors significantly improved their thermal stability and efficiently prolonged their shelf life at 4 °C and 37 °C. Furthermore, the immobilized growth factors could be reused at least three times without losing their stimulation effect on cell proliferation. This photo-reactive gelatin-based immobilization of growth factors appears to be a promising method for serum-free hMSC culturing.
Co-reporter:Binata Joddar, Takashi Hoshiba, Guoping Chen and Yoshihiro Ito
Biomaterials Science (2013-Present) 2014 - vol. 2(Issue 11) pp:NaN1603-1603
Publication Date(Web):2014/08/08
DOI:10.1039/C4BM00126E
There have been great efforts to develop cell culture systems to regulate stem cell functions. Development of cell culture substrates is one of the important approaches for stem cell culture because substrates influence stem cell functions such as attachment, proliferation, self-renewal, and induction of differentiation. Stem cells are surrounded by their specific microenvironments in vivo, composed of cells, cytokines, and an extracellular matrix (ECM), which may dynamically change and affect cellular activities accordingly. To mimic such microenvironments, cell culture substrates can be prepared by coating bioactive proteins such as ECM proteins and signaling molecules as ligands for cell surface receptors. Compared with protein-coated substrates, cell- and cell-formed ECM-derived substrates have shown great progress and attracted significant attention as functional and prospective biomaterials for stem cell culture and regenerative medicine. In this review, we summarize the latest progress of these new substrates derived from cells and cell-formed ECMs.
Co-reporter:Takanori Uzawa, Seiichi Tada, Wei Wang and Yoshihiro Ito
Chemical Communications 2013 - vol. 49(Issue 18) pp:NaN1795-1795
Publication Date(Web):2013/01/02
DOI:10.1039/C2CC36348H
The possibility of evolving a commonly existing biomolecule into a variety of functional biomolecules has now been realized in the form of aptamers through the development of in vitro selection. In addition to their high affinity and high specificity for the desired targets, aptamers are easily synthesized chemically and can be modified for downstream applications. Although aptamers were originally selected from a library containing only natural components, the past decade has seen a wealth of new aptamers selected from libraries containing unnatural components to provide new aptamer functions artificially. In this review, we highlight this transition (the shift between selection from natural components and selection from unnatural components) and the applications of selected aptamers.
Co-reporter:Qingmin Zang, Seiichi Tada, Takanori Uzawa, Daisuke Kiga, Masayuki Yamamura and Yoshihiro Ito
Chemical Communications 2015 - vol. 51(Issue 76) pp:NaN14388-14388
Publication Date(Web):2015/07/31
DOI:10.1039/C5CC04486C
Polyethylene glycol (PEG) of different lengths was genetically incorporated into the backbone of a polypeptide using stop-anticodon and frameshift anticodon-containing tRNAs, which were acylated with PEG-containing amino acids.
Co-reporter:Baiju G. Nair, Yukiko Nakano, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2014 - vol. 50(Issue 5) pp:NaN604-604
Publication Date(Web):2013/11/04
DOI:10.1039/C3CC45907A
Protein nanotubes formed by layer-by-layer (LbL) assembly can penetrate cells and act as nanopores for direct transmembrane delivery of chemical compounds.
Co-reporter:Wei Wang, Takanori Uzawa, Naoya Tochio, Jumpei Hamatsu, Yoshinori Hirano, Seiichi Tada, Hisao Saneyoshi, Takanori Kigawa, Nobuhiro Hayashi, Yutaka Ito, Makoto Taiji, Toshiro Aigaki and Yoshihiro Ito
Chemical Communications 2014 - vol. 50(Issue 22) pp:NaN2964-2964
Publication Date(Web):2013/11/18
DOI:10.1039/C3CC47624C
A peptide that binds and emits fluorescence in response to conformational change in a target protein was developed by in vitro selection using tRNA carrying a fluorogenic amino acid. This technology could prove to be useful for the development of separation-free immunoassays and bio-imaging analyses.
Co-reporter:Aya Shibata, Yoshihiro Ito and Hiroshi Abe
Chemical Communications 2013 - vol. 49(Issue 3) pp:NaN272-272
Publication Date(Web):2012/11/13
DOI:10.1039/C2CC37826D
We have developed a system to release a biologically active molecule in response to the sequence of a target gene. The releasing system, which was triggered by the reduction of an azidomethyl group, was successfully applied to protein expression induced by the release of IPTG triggered by endogenous RNA in bacterial cells.
Co-reporter:Naoko Abe, Hiroshi Abe, Takahito Ohshiro, Yuko Nakashima, Mizuo Maeda and Yoshihiro Ito
Chemical Communications 2011 - vol. 47(Issue 7) pp:NaN2127-2127
Publication Date(Web):2010/12/21
DOI:10.1039/C0CC04551A
Small circular double-stranded RNAs (dsRNAs) were synthesized. The structural analysis by atomic force microscopy gave direct images for the interpretation of the structural strain present in circular dsRNAs. Finally, we demonstrated that circular dsRNA caused RNAi effect in cells.
Co-reporter:Aya Shibata, Hiroshi Abe, Mika Ito, Yuko Kondo, Shigeru Shimizu, Kyoko Aikawa and Yoshihiro Ito
Chemical Communications 2009(Issue 43) pp:NaN6588-6588
Publication Date(Web):2009/10/05
DOI:10.1039/B912896D
We have developed an SNAr reaction-triggered fluorescence probe using a new fluorogenic compound derivatized from 7-aminocoumarin for oligonucleotides detection.
Co-reporter:Binata Joddar and Yoshihiro Ito
Journal of Materials Chemistry A 2011 - vol. 21(Issue 36) pp:NaN13755-13755
Publication Date(Web):2011/07/28
DOI:10.1039/C1JM10984G
It is very important to modify the surfaces of biomaterials for regulation of cells in the development of regenerative medicine or tissue engineering. Biomaterials are categorized into three primary types, metallic, ceramic, and polymers. Here the biological modification of biomaterial surfaces such as metals, ceramics, and polymers and the effects of such biological modifications are discussed. It is well known that cellular compatibility is regulated by three interactions: one is with extracellular matrices (ECM), second with neighboring cells, and third with soluble biosignals such as growth factors. Biomaterial researchers have immobilized ECM, cell adhesion factors, and growth factors on various materials to regulate cellular functions. Herein, biosignaling of ECM, cell adhesion factors, and growth factors are reviewed and biomaterial designs to activate biosignaling mechanisms are discussed.
Co-reporter:Liping Zhu, Wei Wang, Haixu Zhao, Muye Xu, Seiichi Tada, Takanori Uzawa, Mingzhe Liu and Yoshihiro Ito
Organic & Biomolecular Chemistry 2015 - vol. 13(Issue 38) pp:NaN9812-9812
Publication Date(Web):2015/08/04
DOI:10.1039/C5OB01271F
When minimal functional sequences are used, it is possible to integrate multiple functions on a single peptide chain, like a “single stroke drawing”. Here a dual functional peptide was designed by combining in vitro selected catalytic and binding activities. For catalytic activity, we performed in vitro selection for a peptide aptamer binding to hemin by using ribosome display and isolated a peptide that had peroxidase activity in the presence of hemin. By combining the selected catalytic peptide with a peptide antigen, which can be recognized by an antibody, an enzyme–antibody conjugate-like peptide was obtained. This study demonstrates a successful strategy to create dual functionalized peptide chains for use in immunoassays.
Co-reporter:Kazuhiro Furukawa, Hiroshi Abe, Jin Wang, Miwako Uda, Hiroyuki Koshino, Satoshi Tsuneda and Yoshihiro Ito
Organic & Biomolecular Chemistry 2009 - vol. 7(Issue 4) pp:NaN677-677
Publication Date(Web):2008/12/12
DOI:10.1039/B817228E
We have developed a new red fluorogenic compound derived from naphthorhodamine for a reduction-triggered fluorescence probe to sense oligonucleotides. The fluorogenic reaction between naphthorhodamine azide derivatives and reducing reagents such as triphenylphosphine (TPP) on the DNA target does not use any enzyme or reagent, and fluoresces at 650 nm. The probes were used for dual color detection of a single nucleotide difference on the leukemia-related bcr/abl gene.
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