Mechanical stimulation of stem cells using cyclic uniaxial strain

Area of Science:

• Biomedical Engineering
• Cell Biology
• Tissue Engineering

Background:

• Mechanical forces are crucial for biological tissue development and maintenance, influencing phenomena like bone remodeling and cell plasticity.
• In vivo monitoring and control of these forces are challenging, necessitating advanced in vitro models.
• Understanding cellular responses to mechanical stimuli requires precise experimental control.

Purpose of the Study:

• To present a detailed in vitro method for applying controlled uniaxial cyclic tensile strain to adherent cells.
• To demonstrate the assembly and operation of a custom-designed bioreactor system for mechanical cell stimulation.
• To provide a flexible protocol adaptable for various cell types and mechanical parameters.

Main Methods:

• Development of a custom bioreactor with a motorized cam-rotor system for applying uniaxial cyclic tensile strain.
• Detailed video protocol for assembling stretch chambers with elastic membranes (e.g., micropatterned silicone).
• Procedures for sterilization, cell seeding (human mesenchymal stem cells), chamber integration, and mechanical parameter adjustment.

Main Results:

• Successful demonstration of a robust method for applying controlled uniaxial tensile strain to cells in vitro.
• The system allows for precise control over strain magnitude, rate, and duration.
• The protocol is adaptable for different cell types, membrane topographies, and coatings.

Conclusions:

• This in vitro method provides a powerful tool for investigating the effects of mechanical forces on cellular behavior.
• The customizable bioreactor system facilitates research into mechanobiology and tissue engineering.
• The protocol enables precise and reproducible mechanical stimulation of cells for diverse research applications.