Molecular Imaging Program, Center for Cancer Research , National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States of America.
Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , Baltimore , Maryland 21250 United States of America.
Bioconjug Chem. 2019 Jan 16;30(1):169-183. doi: 10.1021/acs.bioconjchem.8b00820. Epub 2018 Dec 14.
Near infrared (NIR) fluorescent probes are attractive tools for biomedical in vivo imaging due to the relatively deeper tissue penetration and lower background autofluorescence. Activatable probes are turned on only after binding to their target, further improving target to background ratios. However, the number of available activatable NIR probes is limited. In this study, we introduce two types of activatable NIR fluorophores derived from bacteriochlorin: chlorin-bacteriochlorin energy-transfer dyads and boron-dipyrromethene (BODIPY)-bacteriochlorin energy-transfer dyads. These fluorophores are characterized by multiple narrow excitation bands with relatively strong emission in the NIR. Targeted bacteriochlorin-based antibody or peptide probes have been previously limited by aggregation after conjugation. Polyethylene glycol (PEG) chains were added to improve the hydrophilicity without altering pharmacokinetics of the targeting moieties. These PEGylated bacteriochlorin-based activatable fluorophores have potential as targeted activatable, multicolor NIR fluorescent probes for in vivo applications.
近红外（NIR）荧光探针由于具有相对更深的组织穿透性和更低的背景自发荧光，因此是生物医学体内成像的有吸引力的工具。 只有在与靶标结合后，可激活的探针才会被激活，从而进一步提高靶标与背景的比率。 但是，可用的可激活近红外探针的数量有限。 在这项研究中，我们介绍了两种源自细菌叶绿素的可激活近红外荧光团：叶绿素-细菌叶绿素能量转移二聚体和硼-二吡咯甲川（BODIPY）-细菌叶绿素能量转移二聚体。 这些荧光团的特征是具有多个较窄的激发带，在近红外区域具有相对较强的发射。 以前，针对细菌叶绿素的抗体或肽探针由于缀合后聚集而受到限制。 添加聚乙二醇（PEG）链可提高亲水性，而不会改变靶向部分的药代动力学。 这些聚乙二醇化的基于细菌叶绿素的可激活荧光团具有作为用于体内应用的靶向可激活，多色近红外荧光探针的潜力。
