Cells comprise a basic building block of life and the life science industry is rapidly moving to high-content screening involving cell-based assays for both drug discovery, as well as in biosensing.  Highlights of CFDRC’s work in this area are provided below:

Dielectrophoresis Based Cell Sorting Device

CFDRC has developed a novel cell sorting device that uses dielectrophoretic forces for separation. In this device conventional negative DEP force in a continuous flow stream is manipulated to achieve a separation efficiency of more than 95% percent. The design configurations were arrived by using predictive, multiphysics simulations. The device consists of two electrodes in a wedge format on the bottom and top surfaces of the microchannel. At one side of the channel, near the electrode gap, there is a side channel for separating the desired particles. Mixed fluorescent polystyrene microparticles and bacterial Bacillus in solution were used to demonstrate the separation. The larger particles experience a higher DEP force and are repelled to the side channel, while the smaller particles experience almost no DEP force and are pushed downstream in the main channel due to hydrodynamic convective forces. Similar behavior is seen while separating mammalian cells using antibody-coated microspheres. CFDRC has applied for a patent on this technology.

Cell Lysis Device

CFDRC has developed devices for cell lysis using a

Experiment showing the lysis of mammalian (HL-60) cells before (left) and after (right) activation of AC electric field.

pulsed AC electric field. The device combines DEP trapping of the cell to the region of high electric field strength. Cell lysis takes place when the trans-membrane potential exceeds a critical value. In the wedge-shaped prototype device, upon energization, cells are attracted toward the tips of the activated electrodes. Subsequently, a pulsed AC electric field is applied for lysis. The system has been used to demonstrate the lysis of human and bacterial cells. Lysis efficiencies, defined as the ratio of broken and initially loaded cells, of more than 95% are achieved in steady environment. We have also extended this technique to a flowing system (for high-throughput).

Synthetic Microvascular Network

Cell adhesion is a critical process impacting significant physiological processes including immune response, inflammation and coagulation/hemostasis, among others. These events are currently characterized using adhesion assays in static, cell-culture environments.  In collaboration with Temple University we have developed a novel in-vitro toolkit, termed synthetic microvascular network which reproduces the effect of microcirculation geometry (size, junctions, tortuosity) and hemodynamic parameters (flow rate/shear) on cell adhesion. We have developed procedures to obtain and microfabricate synthetic microvascular networks (SMN), obtained from in-vivo tissue images, on polymer (PDMS) substrate. Cell/particle adhesion to target cells in these networks have been successfully conducted. In addition to physiological realism, other advantages of this platform include disposability and significantly reduced reagent/cell use. CFDRC has applied for a patent on this technology.