Vascular Graft Infections

Vicaretti, Mauro

doi:10.1007/978-3-030-43683-4_29

Cited by 1 publication

(1 citation statement)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Often, the infection is difficult to localize and is only acted out as non-specific clinical manifestations including fever, pain, general malaise, and abnormal laboratory results. One example of a bacterial infection where patients often show unclear clinical symptoms is vascular graft infection. − Upon graft insertion, the implanted material becomes coated with host proteins, which facilitates binding of planktonic bacteria to the artificial surface. − Bacteria grow in a monolayered fashion and start producing an extracellular matrix composed of polysaccharides, proteins, and DNA. Ultimately, a so-called biofilm is formed at the xenobiotic interface, which is constituted by a multicellular array in which the bacteria are found embedded in a compact matrix possessing a complex chemical constitution.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

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.

show abstract