title: Light-guiding hydrogels for cell-based sensing and optogenetic synthesisin vivo.
abstract: Polymer hydrogels are widely used as cell scaffolds for biomedical applications. While the biochemical and biophysical properties of hydrogels have been extensively investigated, little attention has been paid to their potential photonic functionalities. Here, we report cell-integrated polyethylene glycol-based hydrogels for in-vivo optical sensing and therapy applications. Hydrogel patches containing cells were implanted in awake, freely moving mice for several days and shown to offer long-term transparency, biocompatibility, cell-viability, and light-guiding properties (loss: <1 dB/cm). Using optogenetic, glucagon-like peptide-1 (GLP-1) secreting cells, we conducted light-controlled therapy using the hydrogel in a mouse model with type-2 diabetes and attained improved glucose homeostasis. Furthermore, real-time optical readout of encapsulated heat-shock-protein-coupled fluorescent reporter cells made it possible to measure the nanotoxicity of cadmium-based bare and shelled quantum dots (CdTe; CdSe/ZnS)in vivo.
authors.affiliation: Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA. ; WCU Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Choi
authors.affiliation: Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA. ; Wonkwang Institute of Interfused Biomedical Science, Department of Pharmacology, School of Dentistry, Wonkwang University, Seoul, Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Choi
authors.affiliation: WCU Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
authors.forename: Seonghoon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Sedat
authors.initials: S
authors.lastname: Nizamoglu
authors.affiliation: Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA. ; Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, Korea.
authors.forename: Sei Kwang
authors.initials: SK
authors.lastname: Hahn
authors.affiliation: Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA. ; WCU Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
authors.forename: Seok Hyun
authors.initials: SH
authors.lastname: Yun
keywords: Biosensor; Hydrogel; Optical waveguide; Optogenetics; Photomedicine; Synthetic biology