Comment on the “YOPRO-1: A Cyanine-Based Molecular Rotor Probe for Amyloid Fibril Detection”

Sep 30, 2026

The article comments on “YOPRO-1: A Cyanine-Based Molecular Rotor Probe for Amyloid Fibril Detection,” evaluating its promise for sensing amyloid fibrils while emphasizing critical constraints before clinical endorsement. Although YOPRO-1 shows fluorescence enhancement upon binding insulin fibrils, it penetrates living cells, leading to nonspecific intracellular binding and compromised spatial localization. It also binds double-stranded nucleic acids, raising high background signals, and DNA intercalation suggests potential mutagenic and safety risks, alongside unconfirmed blood-brain barrier penetration.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Background and reported advantages

Fluorescence enhancement in binding studies

Key limitations in complex environments

Cellular uptake and nonspecific intracellular interactions

RNA/DNA binding and reduced signal-to-noise

DNA intercalation and mutagenic safety concerns

Translation to in vivo and clinical use

Blood-brain barrier penetration uncertainty

Need for thorough risk assessment

Overall assessment

This article is licensed under CC-BY 4.0 [www.acsabm.org](www.acsabm.org) Comment Comment on the “YOPRO-1: A Cyanine-Based Molecular Rotor Probe for Amyloid Fibril Detection” Karina Kwapiszewska * ACS Appl. Bio Mater. 2025, 8 (4), 3443−3453. DOI: 10.1021/acsabm.5c00186 Cite This: ACS Appl. Bio Mater. 2026, 9, 1−2 Read Online | | | | | | | | --- | --- | --- | --- | --- | --- | | ACCESS | Metrics & More | | Article Recommendations | | *sı Supporting Information | The detection of amyloid fibrils in neurodegenerative diseases remains a noteworthy issue in both research and clinical settings. The identification of YOPRO-1 as a potential amyloid fibril sensor offering superior sensitivity and selectivity appears promising.1 The authors of the original work1 presented a remarkable YOPRO-1 fluorescence enhancement upon binding to insulin fibrils in both buffer and biological fluids (serum). Although these results suggest excellent potential for neurodegenerative disease diagnosis, several crucial limitations associated with YOPRO-1’s cellular interactions demand careful consideration before endorsing its application for amyloid detection, especially in complex biological environments. In recent work, it has been demonstrated that YOPRO-1 penetrates living human cells.2 This property, while potentially advantageous for specific applications,3,4 introduces significant complications for amyloid detection. Cellular uptake means that YOPRO-1 will not exclusively interact with extracellular amyloid deposits but will bind to various intracellular components. This nonspecific distribution compromises the probe’s ability to provide accurate spatial information about amyloid localization, particularly in tissue samples containing both cells and extracellular matrix. A further consequence of YOPRO-1 cellular uptake is its high fluorescence in cells (Figure 1). It was demonstrated that YOPRO-1 binds to double-stranded nucleic acids, which include not only nuclear DNA but also rRNA and tRNA, which are abundant in the whole cell volume.2 This characteristic directly undermines the probe’s utility in complex biological matrices, precisely the capability highlighted as an advantage in the original study. The high background signal would significantly reduce the signal-to-noise ratio, potentially masking the detection of early amyloid formations and limiting the sensitivity in practical applications. The properties mentioned above and the YOPRO-1 primary use as a DNA intercalator5 raise another concern: DNA intercalation suggests potential mutagenic activity, posing safety risks for in vivo applications. DNA intercalator dyes can induce mutations in vivo by inserting between DNA base pairs, which distorts the DNA helix and interferes with replication and transcription processes.6 Additionally, specific intercalating agents have been shown to inhibit topoisomerase II, leading to double-strand breaks and chromosomal rearrangements that contribute to their mutagenic potential.7 The mutagenic properties of these compounds explain why many DNA intercalators are used as chemotherapeutic agents against cancer Figure 1. Intracellular localization of YOPRO-1 in HeLa cells. (A−C) Staining viable HeLa cells in culture (A) with 0.5 μM YOPRO-1 yields bright green fluorescence (B and C, merged image). (D, E) The YOPRO-1 staining is not uniform in the population of cells (B, green fluorescence channel; E, merged image). (F) Confocal imaging of fixed HeLa cells treated with 0.2 μM YOPRO-1 reveals subcellular localization, mainly in the cytoplasm and nucleoli, neglecting solely double-stranded DNA intercalation. Scale bars represent 50 μm. Experimental procedures are described in the Supporting Information. cells while presenting concerns for laboratory safety when handling these dyes. Comprehensive toxicological studies should evaluate these risks before any in vivo application or even extensive ex vivo use with patient sampl

FAQs

What promising advantage does YOPRO-1 have according to the original work?

The original study reports YOPRO-1 fluorescence enhancement upon binding insulin fibrils in both buffer and biological fluids such as serum, suggesting strong sensitivity and selectivity for amyloid fibril sensing.

Why does cellular uptake complicate YOPRO-1’s ability to detect amyloid localization?

Because YOPRO-1 penetrates living cells, it does not interact exclusively with extracellular amyloid deposits; instead, it binds intracellular components, which undermines accurate spatial information about amyloid localization in tissue samples.

What safety and performance concerns are linked to YOPRO-1’s DNA intercalation and nucleic-acid binding?

YOPRO-1 is described as a DNA intercalator, raising concerns about mutagenic activity and in vivo safety. It also binds double-stranded nucleic acids abundant in cells, producing high background fluorescence that can reduce the signal-to-noise ratio and mask early amyloid formations.

Sep 30, 2026

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