A multi-shear perfusion bioreactor for investigating shear stress effects in endothelial cell constructs

Area of Science:

• Biomedical Engineering
• Cell Biology
• Tissue Engineering

Background:

• Advanced cultivation technologies are crucial for controlled cell microenvironments in tissue engineering.
• Physiologically relevant shear stress is a key factor influencing cell behavior and function.

Purpose of the Study:

• To describe a novel micro-fabricated Multi-Shear Perfusion Bioreactor (MSPB).
• To evaluate the simultaneous application of multiple shear stress levels to cell constructs.
• To assess human umbilical vein endothelial cell (HUVEC) responses to varying shear stress.

Main Methods:

• Fabrication of a micro-bioreactor capable of delivering six distinct shear stress levels (1-13 dyne cm(-2)).
• Incorporation of flow-distributing nets for homogeneous fluid flow.
• Cultivation of HUVECs in alginate scaffolds within the MSPB under different shear stress conditions.
• Analysis of cell marker expression (ICAM-1, p-eNOS) and cell sprout length.
• Validation of bioreactor flow using computational fluid dynamics (CFD).

Main Results:

• HUVECs exhibited differential expression of ICAM-1 and p-eNOS in response to three distinct shear stress levels within 24 hours.
• Longer cultivation periods (17 days) under two shear stress levels resulted in varying cell sprout lengths.
• The MSPB system effectively imposed different shear stress levels simultaneously.
• CFD analysis confirmed the validated flow regime within the bioreactor.

Conclusions:

• The Multi-Shear Perfusion Bioreactor (MSPB) is a feasible system for simultaneously applying diverse shear stress levels in tissue engineering.
• HUVEC responses to controlled shear stress in the MSPB confirm its utility for studying mechanotransduction.
• The MSPB facilitates the development of advanced cell culture models for regenerative medicine applications.