Application of d6 transition metal complexes in fluorescence cell imaging

Abstract

Luminescent d(6) transition metal complexes have often been proposed as useful fluorophores for cell imaging due to their attractive photophysical attributes, but until very recently their actual applications have been scarce, and largely limited to ruthenium complexes in DNA and oxygen sensing. In the last few years, however, there has been an increasing number of reports of the design and application in cellular studies of a diverse range of Ir, Re and Ru complexes tailor-made for imaging applications. The design principles, uptake and cellular localisation of this new class of imaging agents are presented in context in this feature article.

Photo-induced cytotoxicity and anti-metastatic activity of ruthenium(ii)–polypyridyl complexes functionalized with tyrosine or tryptophan

“…12,13 Ru(II)-polypyridyl complexes with appropriately functionalized bpy derivative can enhance lipophilicity and can lead to more efficient internalization. [14][15][16][17] Herein, we investigated the use of two Ru(II)-polypyridyl based reagents with pendant tyrosine or tryptophan moiety as efficient PDT reagents. Photo-induced cytotoxicity, anti-metastatic property, cellular uptake and ROSmediated DNA cleaving pathways for these two complexes (1 and 2) are described.…”

Lightening up Ruthenium Complexes to Fight Cancer?

“…[37] These characteristics made them also suitable for bio-imaging purposes. [38,39] In addition to these applications, the potential of such compounds have also been studied in the field of medicinal chemistry. [40][41][42] This field was pioneered by Dwyer and coworkers, who first investigated the biological activity of polypyridyl transition metal complexes.…”

Fluorescent Labeling of Plasmid DNA and mRNA: Gains and Losses of Current Labeling Strategies

“…Hence, one 24 of the most importance principles of fluorescence microscopy was born. Around the same time, 25 Ernst Abbe published his theoretical analysis of the role of diffraction in optical microscopy 2 . 26 It was however only at the start of the 20 th century that a prototype of a bright field fluorescence 27 microscope was built at the Carl Zeiss factory.…”

“…Negatively charged nucleic acids are mostly complexed 24 with positively charged carriers to enhance cellular uptake of the complexes which are formed. 25 Designing new delivery vehicles is crucial for the future success of these treatments. Live-cell 26 imaging will undeniably play an important role in unraveling the different steps of the 27 transfection pathway 6 .…”

“…22 Incorporation of modified nucleotides 23 Apart from the labeling strategies mentioned above, another popular commercially available 24 option is the in vitro incorporation of modified nucleotides into the polynucleotide backbone. 25 The term "modified" stands for a nucleotide that differs from the naturally occurring 26 nucleotides through the addition of a functional moiety. At first, especially the nucleotides with 27 radioactive atoms ( 32 P, 33 P, 14 C, 3 H, 35 S) were used, but nowadays radioactive labels are often 28…”