Equilibrium ex vivo calibration of homogenized tissue for in vivo SPME quantitation of doxorubicin in lung tissue

Anna Roszkowska; Marcos Tascon; Barbara Bojko; Krzysztof Goryński; Pedro Reck Dos Santos; Marcelo Cypel; Janusz Pawliszyn

doi:10.1016/j.talanta.2018.02.049

Equilibrium ex vivo calibration of homogenized tissue for in vivo SPME quantitation of doxorubicin in lung tissue

Talanta. 2018 Jun 1:183:304-310. doi: 10.1016/j.talanta.2018.02.049. Epub 2018 Feb 15.

Authors

Anna Roszkowska¹, Marcos Tascon¹, Barbara Bojko², Krzysztof Goryński², Pedro Reck Dos Santos³, Marcelo Cypel³, Janusz Pawliszyn⁴

Affiliations

¹ Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
² Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Torun, Poland.
³ Latner Thoracic Surgery Research Laboratories, Toronto General Research Institute, University Health Network and Department of Surgery, University of Toronto, Toronto, ON, Canada.
⁴ Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. Electronic address: janusz@uwaterloo.ca.

PMID: 29567180
DOI: 10.1016/j.talanta.2018.02.049

Abstract

The fast and sensitive determination of concentrations of anticancer drugs in specific organs can improve the efficacy of chemotherapy and minimize its adverse effects. In this paper, ex vivo solid-phase microextraction (SPME) coupled to LC-MS/MS as a method for rapidly quantitating doxorubicin (DOX) in lung tissue was optimized. Furthermore, the theoretical and practical challenges related to the real-time monitoring of DOX levels in the lung tissue of a living organism (in vivo SPME) are presented. In addition, several parameters for ex vivo/in vivo SPME studies, such as extraction efficiency of autoclaved fibers, intact/homogenized tissue differences, critical tissue amount, and the absence of an internal standard are thoroughly examined. To both accurately quantify DOX in solid tissue and minimize the error related to the lack of an internal standard, a calibration method at equilibrium conditions was chosen. In optimized ex vivo SPME conditions, the targeted compound was extracted by directly introducing a 15 mm (45 µm thickness) mixed-mode fiber into 15 g of homogenized tissue for 20 min, followed by a desorption step in an optimal solvent mixture. The detection limit for DOX was 2.5 µg g^-1 of tissue. The optimized ex vivo SPME method was successfully applied for the analysis of DOX in real pig lung biopsies, providing an averaged accuracy and precision of 103.2% and 12.3%, respectively. Additionally, a comparison between SPME and solid-liquid extraction revealed good agreement. The results presented herein demonstrate that the developed SPME method radically simplifies the sample preparation step and eliminates the need for tissue biopsies. These results suggest that SPME can accurately quantify DOX in different tissue compartments and can be potentially useful for monitoring and adjusting drug dosages during chemotherapy in order to achieve effective and safe concentrations of doxorubicin.

Keywords: Doxorubicin; In vivo SPME; LC-MS/MS; Lung; SPME calibration; Therapeutic drug monitoring.

MeSH terms

Animals
Calibration
Chromatography, Liquid
Doxorubicin / analysis*
Lung / chemistry*
Solid Phase Microextraction*
Swine
Tandem Mass Spectrometry

Substances

Doxorubicin