2. Academic Validation
  3. Versatile Near-Infrared Super-Resolution Imaging of Amyloid Fibrils with the Fluorogenic Probe CRANAD-2

Versatile Near-Infrared Super-Resolution Imaging of Amyloid Fibrils with the Fluorogenic Probe CRANAD-2

  • Chemistry. 2022 Apr 1;28(19):e202200026. doi: 10.1002/chem.202200026.
Joaquim Torra 1,  Felipe Viela 1,  Diego Megías 2,  Begoña Sot 1 3,  Cristina Flors 1 3
Affiliations

Affiliations

  • 1 Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanociencia), Madrid, 28049, Spain.
  • 2 Confocal Microscopy Unit; Biotechnology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, 28029, Spain.
  • 3 Nanobiotechnology Unit Associated to the National Center for Biotechnology (CNB-CSIC-IMDEA), Madrid, 28049, Spain.
PMID: 35178798 DOI: 10.1002/chem.202200026
Abstract

CRANAD-2 is a fluorogenic curcumin derivative used for near-infrared detection and imaging in vivo of amyloid aggregates, which are involved in neurodegenerative diseases. We explore the performance of CRANAD-2 in two super-resolution imaging techniques, namely stimulated emission depletion (STED) and single-molecule localization microscopy (SMLM), with markedly different fluorophore requirements. By conveniently adapting the concentration of CRANAD-2, which transiently binds to amyloid fibrils, we show that it performs well in both techniques, achieving a resolution in the range of 45-55 nm. Correlation of SMLM with atomic force microscopy (AFM) validates the resolution of fine features in the reconstructed super-resolved image. The good performance and versatility of CRANAD-2 provides a powerful tool for near-infrared nanoscopic imaging of amyloids in vitro and in vivo.

Keywords

amyloid fibrils; curcumin derivatives; exchangeable fluorophore.; single-molecule localization microscopy; stimulated emission depletion microscopy; super-resolution imaging; transient binding.

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