title: Partially photodegradable hybrid hydrogels with elasticity tunable by light irradiation.
abstract: This paper reports a simple technique to synthesize elasticity tunable hybrid hydrogels using photocleavable (N-hydroxysuccinimide terminated photocleavable tetra-arm poly(ethylene glycol); NHS-PC-4armPEG) and non-photocleavable (N-hydroxysuccinimide terminated tetra-arm poly(ethylene glycol); NHS-4armPEG) activated-ester type crosslinkers. Partially photodegradable hybrid hydrogels were synthesized by reacting the crosslinker mixture with amino-terminated tetra-arm poly(ethylene glycol) (amino-4armPEG). The photocleavable crosslinks are cleaved by irradiating light while the non-photocleavable crosslinks remain intact, resulting in decreased elasticity. We demonstrate that hydrogel elasticity can be controlled by adjusting the ratio of photocleavable NHS-PC-4armPEG and non-photocleavable NHS-4armPEG, and by varying the light exposure energy. We also show how micropatterned elasticity can be obtained in the hydrogels by irradiating with micropatterned light. These techniques could provide a novel platform to tailor the elasticity of hydrogels with microscale precision for biological studies in the near future.
authors.affiliation: Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Fumiki
authors.initials: F
authors.lastname: Yanagawa
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan.
authors.forename: Takeomi
authors.initials: T
authors.lastname: Mizutani
authors.affiliation: Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. Electronic address: shinji.sugiura@aist.go.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Sugiura
authors.affiliation: Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Kimio
authors.initials: K
authors.lastname: Sumaru
authors.affiliation: Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kanamori
mesh_terms: D004548:Elasticity / Q000528:radiation effects*; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D015394:Molecular Structure; D055668:Photochemical Processes; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects
chemical_list: D020100:Hydrogels; D011092:Polyethylene Glycols
keywords: Crosslinker; Elasticity; Hydrogel; Photodegradable