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

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.