μSPE followed by HPLC-MS/MS for the determination of series D and E resolvins in biological matrices

The critical role of acute inflammatory processes is recognized in many chronic diseases; a key point in molecular mechanisms of acute inflammation resolution is represented by a new group of pro-resolving lipid mediators that include distinct families of molecules: lipoxins, resolvins, protectins and maresins, collectively termed specialized pro-resolving mediators (SPMs). In particular, resolvins are active in the picogram to nanogram dose range, whereby they can directly modulate a plethora of anti-inflammatory responses. The presented method proposes an analytical protocol able to extract and to quantify 6 different resolvins from 3 different matrices (plasma, cells and exudates). The method, validated according to the EMA guideline for bioanalysis, exhibited good precision (1%-20%) and accuracy (2%-20%). In particular, the combination of two different sample preparation techniques, Liquid-Liquid Extraction (LLE) and micro-Solid Phase Extraction (mu SPE), applied for the first on this class of molecules, used for the extraction and clean-up respectively, led to high enrichment factor (20 fold) and consequently a high sensitivity (LOQ between 1 and 38 pg mL(-1)); moreover the validation data proved the versatility of mu SPE as clean-up tool as it was capable to manage huge enrichment factor without negatively affect accuracy and precision of analysis. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The critical role of acute inflammatory processes lies in a new group of pro-resolving lipid mediators, including lipoxins, resolvins, protectins and maresins; a proposed analytical protocol for extracting and quantifying multiple resolvins from different matrices showed good precision and accuracy, with a combination of Liquid-Liquid Extraction (LLE) and micro-Solid Phase Extraction (mu SPE) leading to high sensitivity and enrichment factor without affecting accuracy and precision.