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An easy to assemble microfluidic perfusion device with a magnetic clamp
Eugene Tkachenko1, Edgar Gutierrez, Mark H Ginsberg
1Department of Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0726, La Jolla, CA 92093, USA.
Lab on a Chip
|April 8, 2009
Summary
Researchers developed a magnetic clamp for sealing microfluidic chips, enabling reliable cell culture experiments under physiological shear stress. This system allows real-time observation of cell behavior, migration, and viability in vascular flow models.
Area of Science:
- Biomedical Engineering
- Microfluidics
- Cell Biology
Background:
- Accurate simulation of physiological conditions, such as shear stress in the vasculature, is crucial for understanding cell behavior.
- Existing microfluidic systems often face challenges with reliable sealing and precise control of shear stress, limiting experimental reproducibility.
- Endothelial cell response to varying shear stress is fundamental to vascular health and disease.
Purpose of the Study:
- To develop and characterize a novel magnetic clamp for reversible sealing of polydimethylsiloxane (PDMS) microfluidic chips.
- To create a microfluidic chip capable of applying a wide range of physiologically relevant shear stresses to endothelial cells.
- To demonstrate the utility of the system for studying endothelial cell response, including viability, alignment, migration, and real-time imaging under flow.
Main Methods:
- Fabrication and characterization of a magnetic clamp providing uniform pressure for sealing PDMS microfluidic chips against cover glasses.
- Design of a microfluidic chip with 8 distinct regions, enabling a 128-fold variation in substrate shear stress (0.07–9 dyn/cm²).
- Perfusion experiments utilizing differential pressure for pulsatile flow generation, coupled with cell viability assays, wound healing assays, and real-time fluorescent imaging.
Main Results:
- The magnetic clamp achieved reliable sealing up to 40 kPa with minimal microchannel deformation and shear stress variation.
- Endothelial cells exhibited excellent viability and alignment along the flow direction at high shear stresses during 15-40 hour perfusions.
- Cell migration velocities were successfully measured using scratch wound healing assays, and real-time imaging captured fluorescent cell migration under shear flow.
Conclusions:
- The developed magnetic clamp and microfluidic chip system provide a robust and reproducible platform for studying endothelial cell responses to shear stress.
- The system allows for precise control of shear stress and flow dynamics, mimicking vascular conditions effectively.
- This technology facilitates advanced cell-based assays, including real-time migration studies, with minimal perturbation to cell cultures.
