title: Ultrafast fluorescence imaging in vivo with conjugated polymer fluorophores in the second near-infrared window.
abstract: In vivo fluorescence imaging in the second near-infrared window (1.0-1.7 μm) can afford deep tissue penetration and high spatial resolution, owing to the reduced scattering of long-wavelength photons. Here we synthesize a series of low-bandgap donor/acceptor copolymers with tunable emission wavelengths of 1,050-1,350 nm in this window. Non-covalent functionalization with phospholipid-polyethylene glycol results in water-soluble and biocompatible polymeric nanoparticles, allowing for live cell molecular imaging at >1,000 nm with polymer fluorophores for the first time. Importantly, the high quantum yield of the polymer allows for in vivo, deep-tissue and ultrafast imaging of mouse arterial blood flow with an unprecedented frame rate of >25 frames per second. The high time-resolution results in spatially and time resolved imaging of the blood flow pattern in cardiogram waveform over a single cardiac cycle (~200 ms) of a mouse, which has not been observed with fluorescence imaging in this window before.
authors.affiliation: 1] Department of Chemistry, Stanford University, Stanford, California 94305, USA [2].
authors.forename: Guosong
authors.initials: G
authors.lastname: Hong
authors.affiliation: 1] College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China [2] State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China [3] Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha 410083, China [4].
authors.forename: Yingping
authors.initials: Y
authors.lastname: Zou
authors.affiliation: 1] Department of Chemistry, Stanford University, Stanford, California 94305, USA [2].
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Antaris
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Shuo
authors.initials: S
authors.lastname: Diao
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Radiology and Bio-X Program, School of Medicine, Stanford University, Stanford, California 94305, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Cheng
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Changxin
authors.initials: C
authors.lastname: Chen
authors.affiliation: 1] College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China [2] State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China.
authors.forename: Yuehui
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Justin Z
authors.initials: JZ
authors.lastname: Wu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Tao
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Fukunaga
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Dai
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology*; D051379:Mice; D018625:Microscopy, Atomic Force; D057054:Molecular Imaging / Q000379:methods*; D015394:Molecular Structure; D053758:Nanoparticles; D061848:Optical Imaging / Q000379:methods*; D010743:Phospholipids; D011092:Polyethylene Glycols; D011108:Polymers / Q000737:chemistry; D012039:Regional Blood Flow / Q000502:physiology*
chemical_list: D010743:Phospholipids; D011108:Polymers; D011092:Polyethylene Glycols