CDy14: a novel biofilm probe targeting exopolysaccharide Psl

Kwon, Hyeokjin; Kim, Junyoung; Lee, Jung Yeol; Yam, Joey Kuok Hoong; Hultqvist, Louise Dahl; Wang, Xu; Rybtke, Morten; Tolker‐Nielsen, Tim; Kim, Jong-Jin; Kang, Nam‐Young; Yang, Liang; Park, Sung-Jin; Givskov, Michael; Chang, Young‐Tae

doi:10.1039/c8cc05544k

Cited by 11 publications

(9 citation statements)

References 17 publications

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“…For the diagnosis of vascular graft infections, positive cultures are considered as the reference standard, but in clinical practice, they are often difficult to obtain. This diagnostic challenge has triggered the use of imaging techniques to localize such infection foci in early stages. − However, these species did not carry specific targeting units and did not include steady-state or time-resolved micro(spectro)scopic studies to understand the microenvironmental influences on the photophysical properties of the label.…”

Section: Introductionsupporting

confidence: 75%

Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms

et al. 2021

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In this work, the synthesis, structural and photophysical characterization of six phosphorescent H 2 O-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (Φ L ), lifetimes (τ), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram + and Gram − models, namely, Staphylococcus aureus and Escherichia coli. With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled. By using photoluminescence lifetime imaging microscopy, excited-state lifetimes within S. aureus biofilms were measured. The photoluminescence intensities were drastically boosted, and the excited state lifetimes were significantly prolonged upon binding to the viscous biofilm matrix, mainly due to the suppression of radiationless deactivation pathways upon shielding from physical quenching processes, such as interactions with solvent molecules and 3 O 2 . The best performances were attained for non-aggregating complexes with maltohexaose targeting units and without amide bridges. Notably, in the absence of the maltodextrin, a hydrophobic adamantyl moiety suffices to attain a sizeable labeling capacity. Moreover, photoluminescence studies showed that selected complexes can also effectively interact with E. coli biofilms, where the bacterial cells are able to partially uptake the maltodextrin-based agents. In summary, the herein introduced concepts enable the development of specific biofilm reporters providing spatial resolution as well as lifetime-and spectrum-based readouts. Considering that most theragnostic agents reported so far mainly address metabolically active bacteria at the surface of biofilms but without reaching cells deeply immersed in the matrix, a new platform with a clear structure-property correlation is provided for the early detection of such bacterial arrays.

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Section: Introductionsupporting

confidence: 75%

Conjugated Pt(II) Complexes as Luminescence-Switch-On Reporters Addressing the Microenvironment of Bacterial Biofilms

et al. 2021

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“…It was demonstrated that CDy11 allows for detection using in vivo imaging of P. aeruginosa in implant and corneal infection mice models [ 42 ]. In addition, CDy14 was identified as a potential fluorescent probe to target Psl exopolysaccharide in P. aeruginosa [ 43 ]. In this context, amphiphilic fluorescent carbon dots were developed and applied to assist the characterization of bacterial biofilm matrix [ 44 ].…”

Section: Imaging Of Biofilms and The Diversity Of Detection Methodsmentioning

confidence: 99%

The Two Weapons against Bacterial Biofilms: Detection and Treatment

et al. 2021

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Bacterial biofilms are defined as complex aggregates of bacteria that grow attached to surfaces or are associated with interfaces. Bacteria within biofilms are embedded in a self-produced extracellular matrix made of polysaccharides, nucleic acids, and proteins. It is recognized that bacterial biofilms are responsible for the majority of microbial infections that occur in the human body, and that biofilm-related infections are extremely difficult to treat. This is related with the fact that microbial cells in biofilms exhibit increased resistance levels to antibiotics in comparison with planktonic (free-floating) cells. In the last years, the introduction into the market of novel compounds that can overcome the resistance to antimicrobial agents associated with biofilm infection has slowed down. If this situation is not altered, millions of lives are at risk, and this will also strongly affect the world economy. As such, research into the identification and eradication of biofilms is important for the future of human health. In this sense, this article provides an overview of techniques developed to detect and imaging biofilms as well as recent strategies that can be applied to treat biofilms during the several biofilm formation steps.

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“…4). 22 High cyclic-di-GMP enhances biofilm formation, leading to overexpression of exopolysaccharides (Psl & Pel) and extracellular DNA. The binding partner of CDy14 was elucidated to be Psl by examining Psl-deficient and Pel-deficient P. aeruginosa mutants and Psl-selective lectin tests.…”

Section: Bacteriamentioning

confidence: 99%