Multi-physiological Parameters Similarity Design of a Gut-on-a-Chip by Computational Simulation

Gut-on-chips (GoCs) serve as crucial platforms for replicating the physiological and pathological environment of the human intestine, facilitating drug screening, toxicological assessments, and disease mechanism investigations. However, current GoC designs face challenges in simultaneously replicating key physiological parameters, including Reynolds number, shear stress on the cell surface, and physiological oxygen gradients. To address this challenge, we propose an innovative biomimetic design for GoC based on the similarity principle. By establishing a proportional relationship between in vivo villus height and the protrusions formed by cell growth within GoC, we achieve geometric similarity between the chip and the intestine. Numerical simulations are employed to analyze the influence of operational parameters on critical physiological conditions. Results indicate that within an optimal flow rate range, the Re (0.197–0.25) and cell surface shear stress (0.02 dyne/cm²) in the GoC channel closely match physiological conditions. Additionally, to mitigate the high oxygen permeability of PDMS, a PVDC shielding layer is introduced to restrict oxygen diffusion, thereby stabilizing the oxygen partial pressure gradient (0.013–0.077 mol/m³) within the chip, aligning it more closely with in vivo levels. This biomimetic design strategy effectively optimizes the fluid dynamic parameters and oxygen microenvironment of GoC, enhancing their physiological relevance and offering robust support for precise intestinal function modeling and pathological research.