Department of Chemistry, Stanford University, Stanford, CA 94305.
Department of Materials Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, China.
Proc Natl Acad Sci U S A. 2017 Jan 31;114(5):962-967. doi: 10.1073/pnas.1617990114. Epub 2017 Jan 17.
Fluorescence imaging multiplicity of biological systems is an area of intense focus, currently limited to fluorescence channels in the visible and first near-infrared (NIR-I; ∼700-900 nm) spectral regions. The development of conjugatable fluorophores with longer wavelength emission is highly desired to afford more targeting channels, reduce background autofluorescence, and achieve deeper tissue imaging depths. We have developed NIR-II (1,000-1,700 nm) molecular imaging agents with a bright NIR-II fluorophore through high-efficiency click chemistry to specific molecular antibodies. Relying on buoyant density differences during density gradient ultracentrifugation separations, highly pure NIR-II fluorophore-antibody conjugates emitting ∼1,100 nm were obtained for use as molecular-specific NIR-II probes. This facilitated 3D staining of ∼170-μm histological brain tissues sections on a home-built confocal microscope, demonstrating multicolor molecular imaging across both the NIR-I and NIR-II windows (800-1,700 nm).
荧光成像的生物系统多样性是一个备受关注的领域，目前仅限于可见光谱和近红外一区（NIR-I；∼700-900nm）的荧光通道。强烈需要开发具有更长波长发射的可共轭荧光团，以提供更多的靶向通道，减少背景自发荧光，并实现更深的组织成像深度。我们通过高效的点击化学，将明亮的 NIR-II 荧光团与特定的分子抗体结合，开发了 NIR-II（1000-1700nm）分子成像剂。利用密度梯度超速离心分离过程中的浮力密度差异，获得了发射波长约为 1100nm 的高纯度 NIR-II 荧光团-抗体缀合物，用作分子特异性 NIR-II 探针。这使得可以在自制的共聚焦显微镜上对约 170μm 厚的组织学脑切片进行 3D 染色，在 NIR-I 和 NIR-II 窗口（800-1700nm）实现多色分子成像。
