The Lattice-Boltzmann Modeling of Microflows in a Cell Culture Microdevice for High-Throughput Drug Screening

Abstract

The aim of our research was to develop a numerical model of microflows occurring in the culture chambers (CC) of a microfluidic device of our construction for high-throughput drug screening. The incompressible fluid flow model is based on the lattice-Boltzmann equation, with an external body force term approximated by the He-Shan-Doolen scheme and the Bhatnagar-Gross-Krook approximation of the collision operator. The model accuracy was validated by the algebraic solution of the Navier–Stokes equation (NSE) for a fully developed duct flow, as well as experimentally. The mean velocity prediction error for the middle-length cross-section of CC was 1.0%, comparing to the NSE algebraic solution. The mean error of volumetric flow rate prediction was 6.1%, comparing to the experimental results. The analysis of flow hydrodynamics showed that the discrepancies from the plug-flow-like velocity profile are observed close to the inlets only, and do not influence cell cultures in the working area of CC. Within its workspace area, the biochip provides stable and homogeneous fully developed laminar flow conditions, which make the procedures of gradient generation, cell seeding, and cell-staining repeatable and uniform across CC, and weakly dependent on perturbations.

Analysis of Static Molecular Gradients in a High-Throughput Drug Screening Microfluidic Assay

“…In practice, the procedure, in particular, is not sensitive to the angle and time of chip tilts, as fluids flow in chambers until reservoirs are emptied, and chambers' surface wettability prevents fluid from escaping from chambers. The concentration gradient is not dependent on the molecular weights of substances as a mechanism of its generation is advective [29].…”