A novel dual‐flow bioreactor simulates increased fluorescein permeability in epithelial tissue barriers

Abstract

Permeability studies across epithelial barriers are of primary importance in drug delivery as well as in toxicology. However, traditional in vitro models do not adequately mimic the dynamic environment of physiological barriers. Here, we describe a novel two-chamber modular bioreactor for dynamic in vitro studies of epithelial cells. The fluid dynamic environment of the bioreactor was characterized using computational fluid dynamic models and measurements of pressure gradients for different combinations of flow rates in the apical and basal chambers. Cell culture experiments were then performed with fully differentiated Caco-2 cells as a model of the intestinal epithelium, comparing the effect of media flow applied in the bioreactor with traditional static transwells. The flow increases barrier integrity and tight junction expression of Caco-2 cells with respect to the static controls. Fluorescein permeability increased threefold in the dynamic system, indicating that the stimulus induced by flow increases transport across the barrier, closely mimicking the in vivo situation. The results are of interest for studying the influence of mechanical stimuli on cells, and underline the importance of developing more physiologically relevant in vitro tissue models. The bioreactor can be used to study drug delivery, chemical, or nanomaterial toxicity and to engineer barrier tissues.

Environmental Control in Flow Bioreactors

“…The same flow rate used in all the cell culture experiments (200 µL/min) was applied. The Vegabar 14 sensor (VEGA Grieshaber KG, Schiltach, Germany, dynamic range: −10 to 10 kPa, resolution: 0.02 kPa) was connected to the inlet and the outlet of the fluidic chamber thought three-way valves, and the pressure signal automatically acquired for 3 min and stored using an appropriate graphical user interface developed in F#, as reported in [23]. To confirm that the hydrostatic overpressure generated by SUITE in the mixing chamber affects the whole fluidic circuit, the same measurements were performed in a LB1 bioreactor connected to the SUITE platform and to the fluidic circuit.…”

Dual flow bioreactor with ultrathin microporous TEER sensing membrane for evaluation of nanoparticle toxicity

“…The fluidic chamber is based on the single compartment bioreactor reported in Mazzei et al [13] and its two compartment, two-flow module for epithelial cultures described in Giusti et al [14]. In the latter bioreactor Caco-2 intestinal epithelial cells were shown to possess increased TEER values and enhanced fluorescein passage upon exposure to apical and basal medium flow.…”

“…In particular we analysed flow-mediated transport using COMSOL Multiphysics (COSMOL AB, Stockholm, Sweden, version 3.4), using the same methods described in Giusti et al [14]. The wall shear stress in the human intestine is 2.10 -4 -8.10 -3 Pa [15].…”

Polymeric Microporous Nanofilms as Smart Platforms for <italic>in Vitro</italic> Assessment of Nanoparticle Translocation and Caco-2 Cell Culture

“…FITC and nanoparticle passage was quantified for both PLLA nanofilms and standard polycarbonate membranes, for up to 24 h after starting the experiment. They were fitted using the following function [31]:…”