Highly Sensitive In Vitro Methods for Detection of Residual Undifferentiated Cells in Retinal Pigment Epithelial Cells Derived from Human iPS Cells

Human induced pluripotent stem cells (hiPSCs) possess the capabilities of self-renewal and differentiation into multiple cell types, and they are free of the ethical problems associated with human embryonic stem cells (hESCs). These characteristics make hiPSCs a promising choice for future regenerative medicine research. There are significant obstacles, however, preventing the clinical use of hiPSCs. One of the most obvious safety issues is the presence of residual undifferentiated cells that have tumorigenic potential. To locate residual undifferentiated cells, in vivo teratoma formation assays have been performed with immunodeficient animals, which is both costly and time-consuming. Here, we examined three in vitro assay methods to detect undifferentiated cells (designated an in vitro tumorigenicity assay): soft agar colony formation assay, flow cytometry assay and quantitative real-time polymerase chain reaction assay (qRT-PCR). Although the soft agar colony formation assay was unable to detect hiPSCs even in the presence of a ROCK inhibitor that permits survival of dissociated hiPSCs/hESCs, the flow cytometry assay using anti-TRA-1-60 antibody detected 0.1% undifferentiated hiPSCs that were spiked in primary retinal pigment epithelial (RPE) cells. Moreover, qRT-PCR with a specific probe and primers was found to detect a trace amount of Lin28 mRNA, which is equivalent to that present in a mixture of a single hiPSC and 5.0×104 RPE cells. Our findings provide highly sensitive and quantitative in vitro assays essential for facilitating safety profiling of hiPSC-derived products for future regenerative medicine research

A Crystallographic Study on Topochemical Photoreaction of Unsymmertic Diolefin Compounds

報告番号: 甲09054 ; 学位授与年月日: 1991-03-29 ; 学位の種別: 課程博士 ; 学位の種類: 工学博士 ; 学位記番号: 博工第2705号 ; 研究科・専攻: 工学系研究科合成化学専

Quantum Beams Applying to Innovative Industrial Materials

Welcome to this Special Issue of Quantum Beam Science entitled “Quantum Beams Applying to Innovative Industrial Materials” [...

Quantum Beams Applying to Innovative Industrial Materials

本稿では、Quantum Beam Science の特集号 “Quantum Beams Applying to Innovative Industrial Materials” 発行に際し、1950年代から現在に至るまでの量子ビーム利用の歴史（工業的な機能性材料の開発・製造から、最近では非破壊の分析ツールとして動作中のエンジンの可視化などに利用されていること）を述べた。また、本特集号では、（１）電子・ガンマ線による架橋やグラフトを用いた新規機能性高分子、（２）金属材料改質などにおける先進イオンビーム技術、（３）電子線リソグラフィなどのナノスケール加工技術、（４）量子ビーム技術の新規応用例に関する論文が掲載されていることを紹介した

Fundamental study on lithf metal oxo clusters for KrF, ArF, and electron beam lithographyographic characteristics o

Some hybrid inorganic-organic resist materials known as metal-oxo clusters were synthesized and lithographic characteristics were investigated. In particular, the dissolution behaviors of metal oxo clusters were investigated by development analyzer. Our results indicated that the solubility of metal oxo clusters thin films decreased by the exposure to KrF, ArF and electron beam (EB). We clarified the sensitivity in Ti-based oxo clusters was higher than that of Zr-based oxo clusters in both KrF and ArF exposure. The dissolution rate in two kinds of metal oxo cluters was almost same in both KrF and ArF exposure. Furthermore, the dissolution contrast of Ti-based oxo clusters was higher compared to Zr-based oxo clusters. Metal oxo clusters resists have the potential as future negative tone photoresist and EB resist materials

Synergizing radiation-induced emulsion graft polymerization of glycidyl methacrylate on polyethylene-coated polypropylene nonwoven fabric by addition of hydrophobic alcohols

The radiation-induced emulsion graft polymerization method is limited for applying concentrations higher than the monomer concentration that enables stable formation of monomer micelles. Furthermore, foaming may occur because of the presence of the surfactant, which is essential for the formation of micelles, resulting in likely splashing around a highly flammable monomer emulsion. In the present study, to overcome these issues, we investigate the effect of added alcohols on the grafting of glycidyl methacrylate (GMA) in emulsion graft polymerization. By adding hydrophobic alcohols to the GMA monomer emulsion of the given system, we succeeded in increasing polymerization rate at low monomer concentrations and developing a highly safe method of emulsion graft polymerization. By adding 0.5 wt% of hydrophobic alcohol such as 1-octanol to the GMA monomer emulsion, the degree of grafting was 4 times higher than in the case without addition. In addition, we successfully reduced the foamability of the GMA monomer emulsion deriving from the surfactant. This is a novel graft polymerization method with promising wide industrial application, as it brings improvements for the existing issues of the conventional emulsion graft polymerization method — (1) emulsion stability under low concentration monomer and (2) process stability due to foaming of the monomer emulsion during polymerization

非対称ジオレフィン化合物のトポケミカル光反応挙動の結晶学的研究

University of Tokyo (東京大学

Control of Radiation/Living Graft Polymerization in the Solid State

放射線グラフト重合と原子移動ラジカル重合を組み合わせた精密グラフト型高分子膜の合成法を開発した。放射線グラフト重合により開始剤となるクロロメチルスチレンをポリ(エーテルエーテルケトン)膜に導入した後、スチレンやスチレンスルホン酸エチルエステルの固相中における原子移動ラジカル重合を行うことでグラフト鎖長の制御を可能とし、さらにリビング性の証明にも成功した

Development of Novel Advanced Cell and Gene Therapy and GMP-Controlled Cell Processing

Abstract: High scientific and ethical practices and reliability in compliance with the ICH-GCP (International conference on harmonization-good clinical practices) are properly required for clinical trials/research involving human subjects. Cell therapy is a general term for treatment modalities conducted by transplantation of human cells, such as blood transfusion, hemopoietic stem cell transplantation, cell transfer immunotherapy, gene therapy, and regenerative therapy. A production system called cell processing including human cell preparation, cultivation, and gene transduction is essential for the development of therapies using cells, and the quality control thereof must be performed in compliance with the good manufacturing practice (GMP). At the moment, however, Japan is far behind in the formulation of rules for cell processing, which should be evolved without delay in order to promote the development of advanced therapy. In particular, it is urgent to construct an institutional GMP (iGMP) specialized for academic institutions and centers, where development of advanced therapy such as regenerative therapy and cell therapy is being undertaken