A Novel Pulse Damper for Endothelial Cell Flow Bioreactors

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Cell Biology

Background:

• Peristaltic pumps (PP) are widely used in flow bioreactors for their sterile, non-contact design.
• However, the pulsatile flow generated by PPs can negatively impact cultured cells, particularly endothelial cells (EC).
• This pulsatility can lead to cellular distress and detachment, compromising experimental outcomes.

Purpose of the Study:

• To develop and evaluate a novel pulse damper (PD) for eliminating pulsatility from peristaltic pumps.
• To assess the impact of reduced pulsatility on endothelial cell behavior in a flow bioreactor.
• To improve the reliability and outcomes of cell culture experiments using flow bioreactors.

Main Methods:

• A pulse damper (PD) was designed and implemented to reduce static pressure and flow rate pulsatility from a peristaltic pump (PP).
• The PD's effectiveness was tested in a macro-scale bioreactor simulating aortic arch conditions at flow rates up to 4 L/min.
• Time-resolved particle image velocimetry was used for velocity field characterization, and endothelial cells (EC) were cultured and exposed to flow with and without the PD.

Main Results:

• The PD achieved nearly 90% effectiveness in reducing flow pulsatility.
• Endothelial cells (EC) exposed to low-flow pulsatile conditions without the PD showed increased distress (2.5-fold ERK1/2 phosphorylation).
• At high flow rates, ECs detached and did not survive without the PD, whereas they remained healthy with the PD.

Conclusions:

• Pulsatile flow from PPs induces EC distress at low flow and detachment/death at high flow, attributed to elevated shear stress.
• The developed PD effectively minimizes hemodynamic stressors, significantly reducing EC distress and improving cell viability.
• Implementing this PD in flow bioreactors is expected to enhance experimental protocols and cell culture reliability.