Verification of microfluidic transfection device
Chaotic advection is a hydrodynamic phenomenon in which enhances stretching and folding of particle interfaces. This modification of fluid-fluid boundaries augments interfacial area (Aref, 1984).Increasing mixing and diffusion is of special importance in flows containing large biomolecules and cells. However, flow in small length-scale microfluidic device is generally laminar with low Reynolds number but special-designed device can lead to spatial advection which cause enhanced agitation in micrometer dimensions. Producing chaotic motion across the cell surface will enable each target plasmid to eventually visit every cell, which will increase the probability of target DNAs that impinge on cell membrane and/or reduce the required amount of target biomolecules (fig. 1A,1B). In this study, we hypothesize that serpentine device can be used to transfect target cells under continuous perfusion.
To determine if hydrodynamic conditions required to induce and sustain chaos in our flow cells, we observed and characterized flow dynamics using computational fluid dynamic simulations. Computational fluid dynamic simulations were used to determine the velocity magnitude and direction of induced chaotic advection in our flow cell (fig.1C). In fact, velocity in inner wall of microfluidic chip is higher than outer wall that can enhances entrance of DNA to cell.