| Project/Area Number |
14380415
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Kanagawa Academy of Science and Technology (2004)
Tokyo Women's Medical University (2002-2003) |
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Principal Investigator |
YOKOYAMA Masayuki Kanagawa Academy of Science and Technology, Nano-medical polymer project, project leader, 高分子ナノメディカルプロジェクト, 研究員 (20220577)
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| Co-Investigator(Kenkyū-buntansha) |
武田 直也 東京女子医科大学, 医学部, 助手 (60338978)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 2004: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2003: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | gene vector / synthetic polymer / gene expression / thermo-responsive polymer / synthetic vector |
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| Research Abstract |
A thermo-responsive polymer was synthesized from N-isopropyl acrylamide, 2-(dimethylamino)ethyl methacrylate, and butylmethacrylate. This copolymer possessed a phase transition temperature at 25℃. Behaviors of its complexation with plasmid DNA were analyzed. When this polymer was complxed with DNA at a N/P charge ratio of 4, zeta-potencial of the formed complex was +14.1mV. Binding affinity of this polymer to DNA was revealed to change on temperature stimuli ; lower affinity at higher temperature. This induced change of affinity could contribute to DNA release from the complex on temperature drop. This affinity change for this polymer was larger than that obtained in previously studied polymers that synthesized with lower contents of 2-(dimethylamino)ethyl methacrylate and butylmethacrylate than the polymer of the present study.
In vitro gene expression assay revealed that this thermo-responsive polymer exhibited thermo-responsive gene expression ; two-fold gene expression upon cooling at 20℃ for 3h. This polymer showed much higher level of gene expression than the previously studied polymer. Furthermore, cytotoxicity of this polymer complex was considerably low such as 80% bioactivity compared to the untreated control. These all results indicated that well controlled DNA binding change using the thermo-responsive copolymer as a synthetic gene vector contributed to obtain high and temperature-controlled in vitro gene expression with low cytotoxicity.
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