Quantitative Assessment of Gut and Vascular Barriers in TTOP, a Cartridge‐Based Bicompartmental Culture Platform

Abstract Bicompartmental in vitro cultures are performed using culture inserts in multi‐well plates. The main challenge of these systems is sample retrieval, which potentially impacts the experimental outcomes. To overcome this challenge, we developed a novel cartridge‐based device called true‐tissue‐on‐platform (TTOP). Our device offers the same handling than multi‐well inserts with a key difference: the cartridge can be easily retrieved and reused without compromising sample morphology. The functionality of TTOP is demonstrated by building gut and vascular barrier in‐vitro models. Barrier tightness is assessed by measuring trans epithelial/endothelial electrical resistance (TEER) and permeability by Lucifer Yellow assay (LY). Geometry‐related effects on TEER are evaluated using a finite element model, comparing TTOP to conventional inserts, which showed an improvement in data robustness and accuracy. Moreover, the device enabled the detection of inflammation‐related changes by comparing untreated versus Tumor‐Necrosis‐Factor‐α‐treated cell barriers, revealing significant differences both with TEER and LY assays. Preliminary data on coupled gut/vascular barriers in the two compartments supported the feasibility of mimicking the gut–vascular barrier in vitro. This new cartridge‐based concept may provide a simple and modular device, accessible to any biological laboratory, enabling controlled handling of the biological samples during and after the experiment.