Designing Zn(ii) and Cu(ii) derivatives as probes for in vitro fluorescence imaging

Abstract

New M(II) bis(thiosemicarbazonato) complexes (M = Ni(II), Cu(II) and Zn(II)) featuring allyl groups at the exocyclic nitrogens have been synthesised. The complexes were characterised in solution by spectroscopic methods and their solid state structures determined by single crystal X-ray diffraction using synchrotron radiation. The Zn(II) complex was found to be intrinsically fluorescent and soluble in biocompatible media. The uptake of this Zn(II) complex in HeLa, MCF-7 and IGROV cancer cells was monitored by fluorescence microscopies (epi- and confocal fluorescence imaging). The radiolabelling to (64)Cu(II) bis(thiosemicarbazonato) complex was performed cleanly by transmetallation from the corresponding Zn(II) species using (64)Cu(OAc)(2).

Interactions Between Amino Acid‐Tagged Naphthalenediimide and Single Walled Carbon Nanotubes for the Design and Construction of New Bioimaging Probes

“…Two control groups were used consisting of 100 μL solvent/ well, i.e 1%: 99% EMEM, as well as 100% EMEM. FEK-4 and MCF-7 cell lines (cultured using standard procedures [106] ) were incubated at 37 °C with the samples prepared as above for 1 h, 3 h, 6 h and 24 h. After incubation, wells were aspirated and solvents replaced by 100 μL of 0.5 mg/mL MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) in EMEM:PBS 9:1, followed by a further incubation (at 37 °C) for 2 h. [107,108] The MTT solution was then aspirated and 100 μL of DMSO was added. Absorbance of resulting samples (directly proportional to cell viability) was measured at 570 nm using a plate reader.…”

Applications of “Hot” and “Cold” Bis(thiosemicarbazonato) Metal Complexes in Multimodal Imaging

“…It was not until 2007 that Pascu et al [68] reported the first metal complexes of Zn(II) and Cu(II) based on acenaphthenequinone bis(thiosemicarbazone) ligands. The intrinsic fluorescence of the acenaphthene group in the backbone of the metal complex allowed the in vitro study of the uptake in different cancer cells.…”

“…The generation process of 68 Ga is more straightforward and affordable for clinical applications, due to the use of a 68 Ge/ 68 Ga generator, which gives a readily available dose in a shorter time and which can be done in a clinical facility. Furthermore, 68 Ga t 1/2 is 68 minutes, which is in the desired range for an imaging experiment. The chemical process where the hot derivative is involved has to be rapid enough, but timing is not as crucial an issue as with 18 F, which has a t 1/2 of 109.7 min, and significantly more challenging multistep radiochemistry, in our experience.…”

“…Due to the availability of generators, the research in 68 Ga aqueous chemistry has strongly arisen in the past decade within the radiochemistry and molecular-imaging research community, which is now geared towards the preclinical, as well as clinical applications, of this radionuclide. The generation process of 68 Ga is more straightforward and affordable for clinical applications, due to the use of a 68 Ge/ 68 Ga generator, which gives a readily available dose in a shorter time and which can be done in a clinical facility. Furthermore, 68 Ga t 1/2 is 68 minutes, which is in the desired range for an imaging experiment.…”

“…This topic, however, will not be discussed herein, as it has been the topic of several different reviews and reference books. [45][46][47] The use of bis(thiosemicarbazonato) metal complexes has normally been limited to PET with 64 Cu or 68 Ga aliphatic complexes. Some research has been conducted on the dual labelling of ATSM ligands with 64 Cu and other radionuclides, such as 123 I [48] or 18 F, [49] in an attempt to understand the biological fate of copper in vivo and clarify the mechanism of hypoxia selectivity.…”