1] Department of Chemistry, Stanford University, Stanford, California 94305, USA [2].
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].
Nat Commun. 2014 Jun 20;5:4206. doi: 10.1038/ncomms5206.
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.
在近红外二区（1.0-1.7μm）进行体内荧光成像是可行的，这是因为长波长光子的散射减少了，所以可以实现深层组织穿透和高空间分辨率。在这里，我们合成了一系列具有可调发射波长（1050-1350nm）的低带隙给体/受体共聚物。通过非共价功能化与磷脂-聚乙二醇，得到了水溶性和生物相容性的聚合物纳米粒子，这使得首次能够在>1000nm 处用聚合物荧光团进行活细胞分子成像。重要的是，聚合物的高量子产率允许对小鼠动脉血流进行体内、深层组织和超快成像，其帧率超过每秒 25 帧，这是前所未有的。高时间分辨率使得能够对单个心动周期（约 200ms）的心电图波形中的血流模式进行空间和时间分辨成像，这是以前在该窗口的荧光成像中没有观察到的。
