Microfluidics

For one of my grad school projects, I designed a microfluidic cell culture device for rapid vacuum-loading of mammalian cells into culture chambers isolated from the damaging effects of shear stress:

Unlike the turbulent and chaotic mixing of fluids that we generally observe in our daily experience (showering, washing dishes, surfing) the fluid dynamics in micron-sized channels is generally ordered and predictable due to the laminar flow regime that dominates at this scale. Hence one of the main advantages of microfluidics is precise spatial and temporal control of fluid flow in the system.

My device enables the dynamic stimulation of cells with any desired waveform of inducer. In the video below, the cells are stimulated with a step function of TNFalpha inducer (shown in purple) which triggers the influx of NFkappaB into the nucleus (with subsequent oscillations of efflux and influx).

Systematic stimulation with different induction profiles can be used to reveal interesting properties of underlying biological networks. The image below highlights the striking differences in individual cell trajectories of NFkappaB nuclear fluorescence signal in response to two different modes of stimulation with TNFalpha.

The cells stimulated with a STEP function respond with a sharp initial peak followed by damped and uniform oscillations, in contrast to cells stimulated with a more natural RAMP function where a high initial peak of NFkappaB nuclear influx is absent.

Read more about my device by following this link:
“Vacuum-assisted cell loading enables shear-free mammalian microfluidic culture.”

Read more about the results of this project in my dissertation by clicking on the PDF icon below.