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Microfluidic devices offer well-defined physical environments that are suitable for effective cell seeding and in vitro three-dimensional (3D) cell culture experiments. These platforms have been employed to model in vivo conditions for studying mechanical forces, cell–extracellular matrix (ECM) interactions, and to elucidate transport mechanisms in 3D tissue-like structures, such as tumor and lymph node organoids. Studies have shown that fluid flow behavior in microfluidic slides (µ-slides) directly influences shear stress, which has emerged as a key factor affecting cell proliferation and differentiation. This study investigates fluid flow in the porous channel of a µ-slide using computational fluid dynamics (CFD) techniques to analyze the impact of perfusion flow rate and porous properties on resulting shear stresses. The model of the µ-slide filled with a permeable biomaterial is considered. Porous media fluid flow in the channel is characterized by adding a momentum loss term to the standard Navier–Stokes equations, with a physiological range of permeability values. Numerical simulations are conducted to obtain data and contour plots of the filtration velocity and flow-induced shear stress distributions within the device channel. The filtration flow is subsequently measured by performing protein perfusions into the slide embedded with native human-derived ECM, while the flow rate is controlled using a syringe pump. The relationships between inlet flow rate and shear stress, as well as filtration flow and ECM permeability, are analyzed. The findings provide insights into the impact of shear stress, informing the optimization of perfusion conditions for studying tissues and cells under fluid flow. 

Human phonation involves the flow-induced vibrations of the vocal folds (VFs) that result from the interaction with airflow through the larynx. Most voice dysfunctions correspond with the fluid–structure interaction (FSI) features as well as the local changes in perfusion within the VF tissue. This study aims to develop a multiphysics computational framework to simulate the interstitial fluid flow dynamics in vibrating VFs using a biphasic description of the tissue and FSI methodology. The integration of FSI and a permeable VF model presents a novel approach to capture phonation physics' complexity and investigate VF tissue's porous nature. The glottal airflow is modeled by the unsteady, incompressible Navier–Stokes equations, and the Brinkman equation is employed to simulate the flow through the saturated porous medium of the VFs. The computational model provides a prediction of tissue deformation metrics and pulsatile glottal flow, in addition to the interstitial fluid velocity and flow circulation within the porous structure. Furthermore, the model is used to characterize the effects of variation in subglottal lung pressure and VF permeability coefficient by conducting parametric studies. Subsequent investigations to quantify the relationships between these input variables, flow perfusion, pore pressure, and vibration amplitude are presented. A linear relationship is found between the vibration amplitude, pore pressure, and filtration flow with subglottal pressure, whereas a nonlinear dependence between the filtration velocity and VF permeability coefficient is detected. The outcomes highlight the importance of poroelasticity in phonation models. 

This paper aims to examine the effects of variations in the vocal fold (VF) morphological features associated with gender on glottal aerodynamics and tissue deformation. Nine three-dimensional geometries of the VFs in the larynx are created with various VF lengths, thicknesses, and depths to perform a parametric analysis according to gender-related geometrical parameters. The computational model is incorporated in a fluid–structure interaction methodology by adopting the transient Navier–Stokes equations to model airflow through the larynx and considering a linear elasticity model for VF dynamics. The model predictions, such as aerodynamic data through the larynx, glottal airflow, and VF deformations, are analyzed. The comparison of the simulation results for the nine cases supports the hypothesis that gender differences in laryngeal dimensions remarkably influence the glottal airflow and deformation of the VFs. Decreasing VF thickness and increasing its length corresponds to a noticeable increase in maximum tissue displacement, while variations in depth affect the flow rate significantly in the small and large larynges. Conversely, we observed that the pressure drop at the glottis is nearly independent of the VF length. A comparison of the glottal area with published imaging data illustrated a direct correlation between the glottal configuration and the morphology of the VFs. 

The mechanisms of abdominal aortic aneurysm (AAA) formation and rupture are controversial in the literature. While the intraluminal thrombus (ILT) plays a crucial role in reducing oxygen flux to the tissue and therefore decreasing the aortic wall strength, other physiological parameters such as the vasa vasorum (VV) oxygen flow and its consumption contribute to altered oxygenation responses of the arterial tissue as well. The goal of this research is to analyse the importance of the aforementioned parameters on oxygen delivery to the aneurysmal wall in a patient-specific AAA. Numerical simulations of coupled blood flow and mass transport with varying levels of VV concentration and oxygen reaction rate coefficient are performed. The hypoperfusion of the adventitial VV and high oxygen consumption are observed to have critical effects on reducing aneurysmal tissue oxygen supply and can therefore exacerbate localized oxygen deprivation. 

Determination of abdominal aortic aneurysm (AAA) rupture risk involves the accurate prediction of mechanical stresses acting on the arterial tissue, as well as the wall strength which has a correlation with oxygen supply within the aneurysmal wall. Our laboratory has previously reported the significance of an intraluminal thrombus (ILT) presence and morphology on localized oxygen deprivation by assuming a uniform consistency of ILT. The aim of this work is to investigate the effects of ILT structural composition on oxygen flow by adopting a multilayered porous framework and comparing a two-layer ILT model with one-layer models. Three-dimensional idealized and patient-specific AAA geometries are generated. Numerical simulations of coupled fluid flow and oxygen transport between blood, arterial wall, and ILT are performed, and spatial variations of oxygen concentrations within the AAA are obtained. A parametric study is conducted, and ILT permeability and oxygen diffusivity parameters are individually varied within a physiological range. A gradient of permeability is also defined to represent the heterogenous structure of ILT. Results for oxygen measures as well as filtration velocities are obtained, and it is found that the presence of any ILT reduces and redistributes the concentrations in the aortic wall markedly. Moreover, it is found that the integration of a porous ILT significantly affects the oxygen transport in AAA and the concentrations are linked to ILT’s permeability values. Regardless of the ILT stratification, maximum variation in wall oxygen concentrations is higher in models with lower permeability, while the concentrations are not sensitive to the value of the diffusion coefficient. Based on the observations, we infer that average one-layer parameters for ILT material characteristics can be used to reasonably estimate the wall oxygen concentrations in aneurysm models.