Tetranuclear Polypyridylruthenium(II) Complexes as Selective Nucleic Acid Stains for Flow Cytometric Analysis of Monocytic and Epithelial Lung Carcinoma Large Extracellular Vesicles

Kartika Wardhani; Aviva Levina; Biyun Sun; Haipei Zou; Georges E. R. Grau; F. Richard Keene; J. Grant Collins; Peter A. Lay

doi:10.3390/biom14060664

Biomolecules (Jun 2024)

Tetranuclear Polypyridylruthenium(II) Complexes as Selective Nucleic Acid Stains for Flow Cytometric Analysis of Monocytic and Epithelial Lung Carcinoma Large Extracellular Vesicles

Kartika Wardhani,
Aviva Levina,
Biyun Sun,
Haipei Zou,
Georges E. R. Grau,
F. Richard Keene,
J. Grant Collins,
Peter A. Lay

Affiliations

Kartika Wardhani: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
Aviva Levina: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
Biyun Sun: School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia
Haipei Zou: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
Georges E. R. Grau: Sydney Nano, The University of Sydney, Sydney, NSW 2006, Australia
F. Richard Keene: Discipline of Chemistry, School of Physics, Chemistry, and Earth Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
J. Grant Collins: School of Science, The University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2612, Australia
Peter A. Lay: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia

DOI: https://doi.org/10.3390/biom14060664
Journal volume & issue: Vol. 14, no. 6
p. 664

Abstract

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Selective staining of extracellular vesicles (EVs) is a major challenge for diagnostic and therapeutic applications. Herein, the EV labeling properties of a new class of tetranuclear polypyridylruthenium(II) complexes, Rubb7-TNL and Rubb7-TL, as phosphorescent stains are described. These new stains have many advantages over standard stains to detect and characterize EVs, including: high specificity for EV staining versus cell staining; high phosphorescence yields; photostability; and a lack of leaching from EVs until incorporation with target cells. As an example of their utility, large EVs released from control (basal) or lipopolysaccharide (LPS)-stimulated THP-1 monocytic leukemia cells were studied as a model of immune system EVs released during bacterial infection. Key findings from EV staining combined with flow cytometry were as follows: (i) LPS-stimulated THP-1 cells generated significantly larger and more numerous large EVs, as compared with those from unstimulated cells; (ii) EVs retained native EV physical properties after staining; and (iii) the new stains selectively differentiated intact large EVs from artificial liposomes, which are models of cell membrane fragments or other lipid-containing debris, as well as distinguished two distinct subpopulations of monocytic EVs within the same experiment, as a result of biochemical differences between unstimulated and LPS-stimulated monocytes. Comparatively, the staining patterns of A549 epithelial lung carcinoma-derived EVs closely resembled those of THP-1 cell line-derived EVs, which highlighted similarities in their selective staining despite their distinct cellular origins. This is consistent with the hypothesis that these new phosphorescent stains target RNA within the EVs.

Published in Biomolecules

ISSN: 2218-273X (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Microbiology
Website: https://www.mdpi.com/journal/biomolecules

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