LC-MS/MS assay coupled with carboxylic acid magnetic bead affinity capture to quantitatively measure cationic host defense peptides (HDPs) in complex matrices with application to preclinical pharmacokinetic studies

Publication date: Available online 2 January 2020Source: Journal of Pharmaceutical and Biomedical AnalysisAuthor(s): Maura J. O’Neill, King Chan, Jesse M. Jaynes, Zachary Knotts, Xia Xu, Abisola Abisoye-Ogunniyan, Theresa Guerin, Jerome Schlomer, Dandan Li, Jeffrey W. Cary, Kanniah Rajasekaran, Clayton Yates, Serguei Kozlov, Thorkell Andresson, Udo RudloffAbstractSynthetic host defense peptides (HDP) are a new class of promising therapeutic agents with potential application in a variety of diseases. RP-182 is a 10mer synthetic HDP design, which selectively reduces M2-like tumor associated macrophages via engagement with the cell surface lectin receptor MRC1/CD206 and is currently being developed as an innate immune defense regulator to improve anti-tumor immunity in immunologically cold tumors. Herein, we describe a sensitive and specific liquid chromatography (LC) coupled to quadrupole electron spray tandem mass spectrometry method to measure positively charged HDPs and HDP peptide fragments in complex biological matrices. Carboxylic acid magnetic beads were used as an affinity-capturing agent to extract the positively charged RP-182 from both mouse plasma and tissue homogenates. Beads were eluted with 0.1% (v/v) formic acid and chromatographic separation was achieved on a Waters 2.1 x 100 mm, 3.5 µm XSelect Peptide CSH C18 column with a Vanguard pre-column of the same phase. MS/MS was performed on a Thermo TSQ Quantiva triple quadrupole mass spectrometer operatin...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research