Development of a 'mechano-active' scaffold for tissue engineering.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cellular Mechanobiology

Background:

• Bone cell mechanotransduction is crucial for skeletal development and repair.
• Voltage-operated calcium channels (VOCC) are key mediators in bone cell response to mechanical load.
• Current tissue engineering scaffolds lack integrated mechanisms to actively modulate cellular responses to mechanical stimuli.

Purpose of the Study:

• To develop a 'mechano-active' scaffold for skeletal tissue engineering.
• To investigate the effect of a calcium channel agonist on bone cell mechanotransduction within a scaffold.
• To enhance load-induced cellular responses and matrix production in engineered bone constructs.

Main Methods:

• Poly(L-lactide) (PLLA) scaffolds were fabricated with and without encapsulated calcium channel agonist (BAY K8644) for slow release.
• Scaffolds were seeded with primary human bone cells or MG63 cells.
• Constructs underwent 13 weeks of culture followed by mechanical stimulation using a four-point bending model.

Main Results:

• Slow-release calcium channel agonist significantly enhanced bone cell responses to mechanical load.
• Cyclical mechanical stimulation (approx. 1000 microstrain) increased collagen type I expression and alkaline phosphatase to protein ratio.
• These increases were further amplified in 'mechano-active' scaffolds containing the agonist.

Conclusions:

• Manipulating voltage-operated calcium channels (VOCC) via targeted agonist delivery can amplify mechanical stimulation-induced matrix production.
• This approach offers a novel strategy for enhancing bone tissue engineering.
• The 'mechano-active' scaffold concept may be applicable to other load-bearing connective tissues.