Point-of-care applicable metabotyping using biofluid-specific electrospun MetaSAMP®s directly amenable to ambient ionization mass spectrometry

While rapid analysis of the human biofluid metabolome is now possible using ambient ionization mass spectrometry (AIMS), these procedures are hampered by in-source matrix effects and reduced sample stability impeding metabolome coverage while remaining relatively labor-intensive. In this study, we aimed at developing biofluid-specific metabolome sampling membranes (MetaSAMP®s, WO2021/191467) that offer a directly applicable and stabilizing substrate for AIMS. Customized rectal, salivary and urinary MetaSAMP®s consisting of multilayered electrospun nanofibrous membranes of blended hydrophilic (polyvinylpyrrolidone and polyacrylonitrile) and lipophilic (polystyrene) polymers supported adequate metabolite ab- , ad-, and desorption. Moreover, MetaSAMP® demonstrated superior metabolome coverage and transport stability compared to crude biofluid analysis and was successfully validated in two pediatric cohorts (MetaBEAse, n=234, feces and urine; OPERA, n=138, saliva). By integrating anthropometric and (patho)physiological with MetaSAMP®-AIMS metabolome data, we obtained significant weight-driven predictions and clinical correlations. In conclusion, MetaSAMP® holds great clinical application potential for on-the-spot metabolic health stratification.