Abstract
Detection of tissue and cell oxygenation is of high importance in fundamental biological and in many medical applications, particularly for monitoring dysfunction in the early stages of cancer. Measurements of the luminescence lifetimes of molecular probes offer a very promising and non-invasive approach to estimate tissue and cell oxygenation in vivo and in vitro. We optimized the evaluation of oxygen detection in vivo by [Ru(Phen)3]2+ in the chicken embryo chorioallantoic membrane model. Its luminescence lifetimes measured in the CAM were analyzed through hierarchical clustering. The detection of the tissue oxygenation at the oxidative stress conditions is still challenging. We applied simultaneous time-resolved recording of the mitochondrial probe MitoTrackerTM OrangeCMTMRos fluorescence and [Ru(Phen)3]2+ phosphorescence imaging in the intact cell without affecting the sensitivities of these molecular probes. [Ru(Phen)3]2+ was demonstrated to be suitable for in vitro detection of oxygen under various stress factors that mimic oxidative stress: other molecular sensors, H2O2, and curcumin-mediated photodynamic therapy in glioma cancer cells. Low phototoxicities of the molecular probes were finally observed. Our study offers a high potential for the application and generalization of tissue oxygenation as an innovative approach based on the similarities between interdependent biological influences. It is particularly suitable for therapeutic approaches targeting metabolic alterations as well as oxygen, glucose, or lipid deprivation.
Highlights
Tissue oxygenation is closely connected with the cell’s metabolic activity
A specific application we present in this work is the use of clustering to facilitate the interpretation of [Ru(Phen)3]2+ luminescence lifetime data obtained in a pre-clinical in vivo model, the chicken embryo chorioallantoic membrane (CAM)
We have shown that hierarchical clustering, a key element in the processing of data sets reflecting the [Ru(Phen)3]2+ oxygen sensitivity, offers many opportunities to carry out the analysis
Summary
Tissue oxygenation is closely connected with the cell’s metabolic activity. In particular, oxygen supply reflects the pathophysiology of cancer cells. Dichlorotris(1,10-phenanthroline)-ruthenium(II) hydrate ([Ru(Phen)3]2+) is an interesting molecule emitting a bright luminescence. This relatively small molecule (700 Da) is sensitive to oxygen in solutions, in cells, and in vivo [4,5,6]. The luminescence lifetime of [Ru(Phen)3]2+ is quenched by oxygen, a mechanism that is governed by the Stern-Volmer relation [3] This hydrophilic molecule is biocompatible and has low phototoxicity when it is localized in the extracellular space [3,7,8]. It takes a long time (24 h) for [Ru(Phen)3]2+ to accumulate in cells [7]. [Ru(Phen)3]2+ is considered as an interesting oxygen-sensitive molecule, mainly to probe the oxygen level in extracellular compartments and solutions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
