In quest of effect directed analysis in the smart laboratory: Automated system for flow-through evaluation of membranotropic effects of emerging contaminants

Abstract

The rate-determining step of the human exposome workflow is the acquisition of physiologically relevant data (e.g., effect directed analysis), which can be performed retrospectively or with ad hoc experiments. In this contribution, an automated system is proposed for evaluating potential interaction mechanisms of xenobiotics across cell membranes, the so-called membranotropic effects, using liposomes as a mimicry of biological membranes, and fluorescent membrane probes. The smart fluidic method features real-time acquisition of fluorescence readouts, data processing and feedback in a fully unsupervised mode. As a proof of concept applicability, the behavior of newly synthesized cholesterol-laden biomimetic liposomes, and the in-vitro potential toxicant action of bisphenol A and diclofenac as model of emerging contaminants on cell membrane surrogates were investigated in a flow-through format. Unattended operation resulted in excellent intermediate precision (<1.5%) and unveiled that diclofenac affected the liposomal bilayer order very slightly, regardless of the cholesterol concentration, because it accumulates at a superficial level, while the membranotropic effect of bisphenol A was more pronounced at low concentration levels of cholesterol because at increased levels, the membrane reduces its permeability.