Polymeric sorbent phase sorptive extraction for radiation metabolomics

Abstract

Novel biodosimetry assays are needed for potential radiological incidents to rapidly assess radiation exposure and guide medical treatments. Mass spectrometry-based metabolomic analysis using a sorptive phase extraction is a rapid and efficient method for radiation-induced biomarkers in biofluids. Here, we developed a chemically functionalized polymeric Sorbent Phase Sorptive Extraction (SPSE) method. This method employs polymeric thin film sorbents with tailored organic functional groups, which directly bind radiation-responsive biomolecules and increase sample absorption capacity. This microporous membrane system enables rapid, high-sensitivity extraction of metabolites spanning a wide polarity range from urine, serum, and whole blood. We characterized the surface morphology, chemical functionality, and hydrophilicity of multiple sorbent-coated cellulose membranes, including plasma-functionalized nylon-6. Matrix interference was evaluated using untargeted metabolomics, and analytical performance was assessed using a targeted multiplex radiation biomarker panel. Urine, serum, and whole blood were collected from male and female C57BL/6 mice (9 weeks old) exposed to X-rays at 1 day (0, 2, 8, 13 Gy) and 7 days (0, 2, 8 Gy) post-irradiation. The membrane types preserve metabolite stability at room temperature for up to two weeks; however, nylon-6-based cellulose paper membranes exhibited the highest surface porosity, absorption capacity, and metabolite recovery. Classifier performance evaluated using receiver operating characteristic analysis demonstrated comparable sensitivity and specificity between SPSE and conventional dilute-and-shoot workflows. Collectively, these results support further development of polymeric sorbent coated paper and fabric-based substrates to increase throughput while eliminating cold-chain requirements. These environmentally conscious design features exemplify principles of green chemistry including lowering chemical waste and operational energy demand.