Nitric oxide delivery system for biological media.

Area of Science:

• Biomedical Engineering
• Chemical Engineering
• Cell Biology

Background:

• Chronically elevated nitric oxide (NO) levels are implicated in diseases like cancer.
• Understanding NO's role requires controlled exposure of biological systems to specific concentrations over time.
• Existing methods lack the precision for long-term, stable NO delivery.

Purpose of the Study:

• To design and validate a bioreactor for controlled, long-term exposure of cells and biomolecules to nitric oxide.
• To achieve stable and predictable nitric oxide (NO) and oxygen (O2) concentrations.
• To develop a predictive model for NO and O2 dynamics within the reactor.

Main Methods:

• Fabrication of a 65ml stirred reactor with a porous PTFE membrane and PDMS tubing for gas delivery.
• Integration of real-time NO and O2 monitoring probes.
• Characterization of gas transport using O2 depletion experiments.
• Development of a mathematical model to predict gas concentrations and transient durations.

Main Results:

• The system achieved steady-state nitric oxide (NO) concentrations ranging from 0.7-2.3μM.
• Nitrite (NO2-) accumulation rates were measured at 53±2μM/h.
• The developed model accurately predicted NO and O2 concentrations and transient times within a few percent.
• Demonstrated successful simultaneous delivery of NO and O2.

Conclusions:

• The developed bioreactor provides a reliable method for exposing biological samples to physiologically relevant nitric oxide (NO) concentrations for extended durations.
• The system's predictive model enhances experimental design and data interpretation.
• This technology facilitates research into the pathological roles of nitric oxide in inflammation, infection, and disease development.