Numerical Investigation of the Dynamical Behavior of a Fluid-Filled Microparticle Suspended in Human Arteriole

The study of artificial microparticles (capsules and vesicles) has gained a growing interest with the emergence of bio-engineering. One of their promoting applications is their use as therapeutic vectors for drug delivery, when capsules and vesicles release their capacity in a targeted environment. The dynamic behavior of capsules and vesicles in confined or unbounded flows was widely studied in the literature and their mechanical response was truthfully described using constitutive laws with good agreement with experiences. However, in a context of biological application, to our knowledge, none of published studies investigating the mechanical response of deformable microparticle took into account the real physiological conditions: the rheological properties of blood such as carrying fluid and the mechanical properties of blood vessels. In this paper, we consider a hyperelastic microparticle suspended in human arteriole. We investigate the deformation of the microparticle resulting from its interaction with blood flow and the arteriolar wall using various capillary numbers and respecting physiological properties of blood and arterial wall. The influence of the blood viscosity model (Newtonian versus shear thinning) is investigated and a comparison with a rigid microchannel and a muscle-embedded arteriole is carried out. The fluid structure interaction (FSI) problem is solved using arbitrary Lagrangian Eulerian (ALE) method. Our simulations have revealed that the arteriolar wall distensibility deeply influences both the deformation and velocity of the microparticle: the deformation strongly increases while the velocity decreases in comparison to an infinitely rigid wall. In the context of therapeutic procedure of targeted drug-delivery, a particular attention should be addressed to these observations, in particular for their implication in the burst mechanism.