Measurement of pO₂by luminescence lifetime spectroscopy: A comparative study of the phototoxicity and sensitivity of [Ru(Phen)₃]²⁺and PdTCPPin vivo

Abstract

Dysfunctions in tissue metabolism can be detected at early stages by oxygen partial pressure (pO ) measurement. The measurement of emission lifetimes offers very promising and non-invasive approach to estimate pO in vivo. This study compares two extensively used oxygen sensors and assesses their in vivo oxygen sensitivity and phototoxic effect. Luminescence lifetime of Ru-polypyridyl complex and of Pd-porphyrin is measured in the Chick's Chorioallantoic Membrane (CAM) model with a dedicated optical fiber-based, time-resolved spectrometer. The Pd-porphyrin luminescence lifetimes measured in the CAM model exposed to different pO levels are longer and have a broader dynamic range (10-100 μs) than those of Ru-polypyridyl complex (0.6-1 μs). The combined statistical analysis based on an estimate of the kurtosis and skewness, bootstrapping method and routine normality tests is performed. The indicators of the averages and signal to noise ratio stability are also calculated. The combination of several data processing allows selection of the better sensor for a given application. In particular, it is found that the advantage of Ru-polypyridyl complex over Pd-porphyrin is two-fold: i) Ru-polypyridyl complex datasets have consistently better statistical characteristics, ii) Ru-polypyridyl exhibits lower cytotoxicity.

Influence of Oxidative Stress on Time-Resolved Oxygen Detection by [Ru(Phen)3]2+ In Vivo and In Vitro

“…[Ru(Phen) 3 ] 2+ can be considered as a metalotoxin. However, it has a low toxicity and phototoxicity in comparison with porphyrins, as we have already demonstrated [3,7,8]. The presence of metalotoxin in cells may induce oxidative stress.…”

“…The luminescence properties of [Ru(Phen) 3 ] 2+ were previously described [3,7,8,10,32]. As a small molecule, [Ru(Phen) 3 ] 2+ leaks out of the vessels and remains in the interstitial space of blood vessel cells [3].…”

“…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].…”

Review: Nanomaterials for Reactive Oxygen Species Detection and Monitoring in Biological Environments

“…Fluorescence and phosphorescence molecular probes have a well-established chemistry and are widely used to detect oxygen and ROS in vitro (Yoshihara et al, 2017;Zhang et al, 2018) and in vivo (Wilson and Cerniglia, 1992;Stepinac et al, 2005;Baudry et al, 2008;Hall et al, 2012;Huntosova et al, 2014;Huntosova et al, 2017). In addition they have high analyte sensitivity, low cost, and a fast response time, enabling rapid, spatially resolved measurements (Terai and Nagano, 2008;Wolfbeis, 2015a).…”

A Versatile Multichannel Instrument for Measurement of Ratiometric Fluorescence Intensity and Phosphorescence Lifetime

“…These articles are referred to as Reference materials, and are indicated by TA:Ref 1 -TA:Ref 4 . These materials have been reported to have stable lifetimes with negligible dependence on the local oxygen level [42], [57]. The first two of these articles contained phosphors that may be excited by green light, while the second two are excited by red light.…”