Predicting different adhesive regimens of circulating particles at blood capillary walls

TL;DR

This paper introduces a computational model to predict how circulating particles interact with blood vessel walls, identifying four distinct adhesion behaviors based on particle and flow properties, aiding targeted therapy design.

Contribution

The study presents a novel combined Lattice Boltzmann Immersed Boundary model that accurately predicts particle-wall interactions and classifies adhesion regimens based on various parameters.

Findings

Model accurately predicts tumor cell rolling velocity.

Four distinct particle-wall interaction regimes identified.

Model applicable for designing targeted therapeutic particles.

Abstract

A fundamental step in the rational design of vascular targeted particles is the firm adhesion at the blood vessel walls. Here, a combined Lattice Boltzmann Immersed Boundary model is presented for predicting the near wall dynamics of circulating particles. A moving least squares algorithm is used to reconstruct the forcing term accounting for the immersed particle, whereas ligand-receptor binding at the particle- wall interface is described via forward and reverse probability distributions. First, it is demonstrated that the model predicts with good accuracy the rolling velocity of tumor cells over an endothelial layer in a microfluidic channel. Then, particle-wall interactions are systematically analyzed in terms of particle geometries (circular, elliptical with aspect ratios 2 and 3), surface ligand densities (0.3, 0.5, 0.7 and 0.9), ligand-receptor bond strengths (1 and 2), and Reynolds numbers (Re = 0.01, 0.1 and 1.0). Depending on these conditions, four different particle-wall interaction regimens are identified, namely not adhering, rolling, sliding and firmly adhering particles. The proposed computational strategy can be efficiently used for predicting the near wall dynamics of particles with arbitrary geometries and surface properties and represents a fundamental tool in the rational design of particles for the specific delivery of therapeutic and imaging agents.