A low resistance microfluidic system for the creation of stable concentration gradients in a defined 3D microenvironment

Abstract

The advent of microfluidic technology allows control and interrogation of cell behavior by defining the local microenvironment with an assortment of biochemical and biophysical stimuli. Many approaches have been developed to create gradients of soluble factors, but the complexity of such systems or their inability to create defined and controllable chemical gradients has limited their widespread implementation. Here we describe a new microfluidic device which employs a parallel arrangement of wells and channels to create stable, linear concentration gradients in a gel region between a source and a sink well. Pressure gradients between the source and sink wells are dissipated through low resistance channels in parallel with the gel channel, thus minimizing the convection of solute in this region. We demonstrate the ability of the new device to quantitate chemotactic responses in a variety of cell types, yielding a complete profile of the migratory response and representing the total number of migrating cells and the distance each cell has migrated. Additionally we show the effect of concentration gradients of the morphogen Sonic hedgehog on the specification of differentiating neural progenitors in a 3-dimensional matrix.

Design of a microfluidic device to quantify dynamic intra-nuclear deformation during cell migration through confining environments

“…18 A more promising approach is to use diffusion across closely spaced sink and source reservoirs to obtain rapidly formed, stable gradients. This has been previously used in chemotaxis devices to study cell migration in 2-D. 22–24 …”

Migrating Myeloid Cells Sense Temporal Dynamics of Chemoattractant Concentrations

“…It is worth noting that many of the custom (Abhyankar et al, 2008; Amadi et al, 2010; Saadi et al, 2007) and commercially available gradient generators (EZ Taxiscan, Ibidi) (Bae et al, 2008; Kanegasaki et al, 2003) used in these experiments require cell introduction into the chamber, followed by gradient establishment. In these cases, there is a gradual increase in chemokine concentration throughout the device as the gradient develops until a steady state persistent stable gradient is established.…”

Microfluidic 3D models of cancer

“…There is a wide variety of applications of compartmentalized systems in cancer biology, including studying cell migration and invasion, creating in vivo-like cellular arrangements and many others[39–43]. One useful advantage to 3D compartmentalization is that it can be used to investigate signaling mechanisms involved in chemotaxis[44]. The types of molecular transport such as diffusion are more controllable in microsystems due to the scale of the system and the ability to control the shape, length, and material of channels[45].…”