Abstract:

Based on the physiological structure of the intestine, a Caco-2/EAhy926 tandem compound model was constructed in order to simulate the intestinal-vascular barrier. This model was applied in the study of transcytosis of nanoparticles, and it was compared with the traditional intestinal cell model in the whole study. Briefly, Fe₃O₄ nanoparticles with a size about 30 nm were used as model nanoparticles, which remained steady during transcytosis. The nanoparticles hardly had cytotoxicity to Caco-2 cells and EAhy926 cells within the incubation concentrations. The cell tandem model was established by connecting upper Caco-2 monolayer and lower EAhy926 monolayer. Based on the FD4 permeability or TEER, all cell models remained integrity within certain period of culture time. The expression of Claudin-4 or VE Cadherin demonstrated the presence of tight junctions. The intact morphology of microfilament F-actin indicated the favorable intracellular connection. It was found that the two-layer cell tandem model created a bigger barrier for the transcytosis of FD4 than Caco-2 and EAhy926 monolayer models, and the translocation of Fe₃O₄ nanoparticles showed a similar pattern. Interestingly, we found that the main barrier of tandem model for nanoparticles was caused by the upper Caco-2 cell monolayer, while the lower layer of EAhy926 monolayer remained high permeability. Generally, the cell tandem compound model established here enabled us to evaluate the impact of both intestinal epithelial and endothelial layer on transcytosis, and it might provide a novel approach to study bio-nano interaction in the intestine.

Key words: Caco-2 cells, EAhy926 cells, Tandem cell model, Fe3O4 nanoparticles, Trans-membrane, Transport mechanism