@misc{oai:repo.qst.go.jp:00065491,
 author = {村山, 周平 and Kos, Petra and Miyata, Kanjiro and 片岡, 一則 and Wagner, Ernst and 加藤, 大 and 村山 周平 and 加藤 大},
 month = {Aug},
 note = {We have developed photo responsible nano gels containing various functional molecules.[2-3] By means of endocytosis, the soft nano gels are internalized by cells, where the encapsulated molecules retain their functionality for more than 3 days. The encapsulated molecules are released and reactivated by UV irradiation. Animal experiments revealed that the acute toxicity of the nano gels is negligible and interestingly the nano gels were excreted in urine within a day.[4] Because the encapsulated molecules are trapped physically by the mesh structure of the nano gels, we expected that there would be few limitations to the types of molecules that could be encapsulated and controlled by means of this technique. Although RNA is chemically unstable, we expected that it could be delivered, via the nano gels, to the cytosol, where it could be released and activated by light stimulation. 
In this study, we prepared nano gel of around 120 nm containing siRNA by mixing four-arm monomers and siRNA. The siRNA containing nano gels were internalized by human ovarian cancer cells (SKOV3-Luc) and were then released by irradiation of the cells with light. Gene-specific silencing was observed approximately 8–48 h after irradiation, as indicated by a luciferase assay. (Fig.1)
Because this technique allows for spatiotemporal regulation of target gene expression within cells by means of a noninvasive external stimulus (light for 30 s), we expect this technique to be useful for basic research and clinical applications such as gene therapy for cancers, genetic disorders, and macular degeneration.
\nReferences: 
1) Shuhei Murayama, Petra Kos, Kanjiro Miyata, Kazunori Kataoka, Ernst Wagner, Masaru Kato, Macromolecular Bioscience, just accepted
2) Shuhei Murayama, Taihei Nishiyama, Kaihei Takagi, Fumi Ishizuka, Tomofumi Santa, Masaru Kato, Chem. Commun., 48, 11461-11463, (2012).
3) Shuhei Murayama, Baowei Su, Kohki Okabe, Akihiro Kishimura, Kensuke Osada, Masayuki Miura, Takashi Funatsu, Kazunori Kataoka, Masaru Kato, Chem. Commun., 48, 8380-8382, (2012).
4) Shuhei Murayama, Jun-ichiro Jo, Yuka Shibata, Kun Liang, Tomofumi Santa, Tsuneo Saga, Ichio Aoki, Masaru Kato, J. Mater. Chem. B, 1, 4932-4938, (2013).
\nKeywords: gene delivery, nano gel, photocontrol, spatiotemporal regulation, siRNA 
Corresponding author*: murayama@nirs.go.jp, The 15th IUMRS-International Conference in Asia(IUMRS-ICA 2014)},
 title = {Photo Responsible Soft nano Gel - Regulation of siRNA-[1]},
 year = {2014}
}