Preclinical models for in vitro mechanical loading of bone-derived cells

Area of Science:

• Biomedical Engineering
• Cell Biology
• Orthopedics

Background:

• Bone cells respond to mechanical forces through mechanotransduction, converting physical stimuli into cellular signals.
• Studying these cellular and molecular responses in vivo is challenging.
• In vitro models allow researchers to investigate mechanotransduction processes more accessibly.

Purpose of the Study:

• To review and summarize methods for applying mechanical stimuli to bone cells in vitro.
• To highlight techniques for replicating physiological and pathological mechanical forces in laboratory settings.

Main Methods:

• Monolayer cultures can be subjected to vibration (low-magnitude, high-frequency), fluid shear (rocking platform, flow chamber), and substrate strain (vacuum-driven, four-point jig).
• Three-dimensional (3D) cultures, including cocultures, can utilize similar stimuli (vibration, perfusion fluid shear, strain, compression) to better mimic the bone microenvironment.
• Specific equipment like the FlexCell system and parallel-plate flow chambers are mentioned for applying these forces.

Main Results:

• Various in vitro techniques exist to apply distinct mechanical stimuli to bone cells.
• Both monolayer and 3D culture systems can be adapted to study cellular responses to mechanical loading.
• 3D cocultures offer a more complex model for investigating cell-cell interactions under mechanical stress.

Conclusions:

• In vitro loading models are essential for dissecting the complexities of bone mechanotransduction.
• A range of methods are available to apply specific mechanical stimuli, facilitating research into bone's response to physical forces.
• These techniques enable a deeper understanding of how bone cells perceive and react to their mechanical environment.