From Photoinduced to Dark Cytotoxicity through an Octahedral Cluster Hydrolysis

Ekaterina V Svezhentseva,Maria S Fufaeva,Ali M Adawi,Svetlana M Miroshnichenko,Michael A Shestopalov,Jean‐Sebastien G Bouillard,Anton A Ivanov,Tatiana N Pozmogova,Olga A Efremova,Anastasiya O Solovieva,Darya V Evtushok,Vadim V Yanshole,Yuri V Mironov,Ilia V Eltsov,Natalia V Kuratieva,Charlotte J Eling,Lidiya V Shestopalova,Yuri A Vorotnikov

doi:10.1002/chem.201804663

Abstract

Octahedral molybdenum and tungsten clusters have potential biological applications in photodynamic therapy and bioimaging. However, poor solubility and hydrolysis stability of these compounds hinder their application. The first water-soluble photoluminescent octahedral tungsten cluster [{W6 I8 }(DMSO)6 ](NO3 )4 was synthesised and demonstrated to be at least one order of magnitude more stable towards hydrolysis than its molybdenum analogue. Biological studies of the compound on larynx carcinoma cells suggest that it has a significant photoinduced toxicity, while the dark toxicity increases with the increase of the degree of hydrolysis. The increase of the dark toxicity is associated with the in situ generation of nanoparticles that clog up the cisternae of rough endoplasmic reticulum.

Highlights

Octahedral molybdenum and tungsten clusters have the potential for biological applications such as photodynamic therapy and bioimaging
Octahedral molybdenum and tungsten clusters of the general formula [{M6X8}L6]n have become a subject of extensive studies after several exceptionally good luminophores were discovered among these compounds, in particular those of molybdenum.[1]
This work as well as several other works demonstrated that molybdenum cluster complexes tend to hydrolyse with partial or full substitution of the apical ligands L by H2O or OH−.[3b, 8-9] Here, we demonstrate the first photoluminescent water-soluble tungsten cluster [{W6I8}(DMSO)6](NO3)4 as well as its molybdenum analogue and compare the kinetics of their hydrolysis

Summary

Introduction

Octahedral molybdenum and tungsten clusters have the potential for biological applications such as photodynamic therapy and bioimaging. The hydrolysis was, noticeably slower for the tungsten compound, as unlike 1, there was still a significant amount of the chemical forms containing up to 5 DMSO ligands in the aqueous solution of 2 after 4 days (ESI Fig. S13).

Results

Conclusion