Structural modification of NIR-II fluorophores for angiography beyond 1300 nm: Expanding the xanthene universe

Chuangli Zhang; Jusung An; Jiasheng Wu; Weimin Liu; Hyeonji Rha; Jong Seung Kim; Pengfei Wang

doi:10.1016/j.bios.2022.114701

Structural modification of NIR-II fluorophores for angiography beyond 1300 nm: Expanding the xanthene universe

Biosens Bioelectron. 2022 Dec 1:217:114701. doi: 10.1016/j.bios.2022.114701. Epub 2022 Sep 9.

Authors

Chuangli Zhang¹, Jusung An², Jiasheng Wu³, Weimin Liu⁴, Hyeonji Rha², Jong Seung Kim⁵, Pengfei Wang⁶

Affiliations

¹ Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China.
² Department of Chemistry, Korea University, Seoul, 02841, South Korea.
³ Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China. Electronic address: wujs@mail.ipc.ac.cn.
⁴ Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, PR China.
⁵ Department of Chemistry, Korea University, Seoul, 02841, South Korea. Electronic address: jongskim@korea.ac.kr.
⁶ Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, PR China. Electronic address: wangpf@mail.ipc.ac.cn.

PMID: 36115125
DOI: 10.1016/j.bios.2022.114701

Abstract

Fluorescence bioimaging via the second near-infrared (NIR-II) window can provide precise images with a low background signal due to attenuated absorption and scattering in biological tissues. However, it is challenging to realize organic fluorophores' absorption/emission wavelength beyond 1300 nm depending on their intrinsic emission of monomers. Reducing parasitic aggregation caused quenching (ACQ) effect is expected as an efficient strategy to achieve fluorescence bioimaging in an ideal region. Herein, two NIR-II xanthene fluorophores (CM1 and CM2) with different side chains on identical skeletons were synthesized. Besides, their corresponding assemblies (CM1 NPs and CM2 NPs) were subsequently prepared, which exhibited distinct spectroscopic properties. Notably, CM2 NPs exhibited a significantly reduced ACQ effect with maximal absorption/emission extended to 1235/1250 nm. Molecular dynamics simulations revealed that intermolecular hydrogen bond, π-π interaction, and CH-π interaction of CM2 were essential for the reduced ACQ effect. In vivo hindlimb angiography showed that CM2 NPs could distinguish the neighboring artery and vein in high resolution. Besides, CM2 NPs could achieve angiography beyond 1300 nm and even resolve capillaries as small as 0.23 mm. This study provides a new strategy for reducing the ACQ effect by controlling different side chains of NIR-II xanthene dyes for angiography beyond 1300 nm.

Keywords: Angiography; NIR-II fluorescence Imaging; Reduced ACQ effect; Xanthene derivatives.

MeSH terms

Angiography
Animals
Biosensing Techniques*
Fluorescent Dyes / chemistry
Ionophores
Optical Imaging / methods
Xanthenes*

Substances

Fluorescent Dyes
Ionophores
Xanthenes