A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

Area of Science:

• Biomedical Engineering
• Physiology
• Microfluidics

Background:

• The human circulatory system is a complex network essential for organ function.
• Current in vitro models lack the complexity to fully replicate systemic circulation.
• Bridging organ-on-a-chip and body-on-a-chip technologies is crucial for advanced research.

Purpose of the Study:

• To develop a microfluidic circulatory system that accurately mimics human systemic circulation in vitro.
• To integrate an on-chip pressure sensor for real-time monitoring and control of circulatory parameters.
• To create a versatile platform for studying cellular responses to physiological flow conditions.

Main Methods:

• A microfluidic device with a cardiac-like pumping system (four pumping units and check valves) was designed.
• Independent control of pumping units allowed adjustable pressure and pump rate to mimic heart function.
• An on-chip capillary-assisted pressure sensor was developed to measure pressure using the ideal gas law.
• Human umbilical vein endothelial cells (HUVECs) were cultured to assess cellular responses to flow.

Main Results:

• The microfluidic system successfully generated pulsatile and unidirectional flow, mimicking human circulation.
• The on-chip pressure sensor accurately measured pressures within the physiological range (0-142.5 mmHg) with a 0.2s response time.
• Mimicked human left ventricular and arterial pressure profiles were achieved.
• Cultured HUVECs demonstrated responses to the mechanically generated arterial-like flow patterns.

Conclusions:

• The developed microfluidic circulatory system provides a sophisticated in vitro platform for studying human systemic circulation.
• The integrated pressure sensor enables precise control and monitoring of physiological parameters.
• This technology advances the development of more complex in vitro models for drug testing and disease research.
• The system demonstrates the potential for studying cellular mechanobiology in a controlled circulatory environment.