Mechanical Loading Improves Engineered Tendon Formation with Muscle-Derived Cells: An In Vivo Analysis

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Cell Biology

Background:

• Previous research indicated muscle-derived cells can form engineered tendons with improved structure.
• The mechanisms of neotendon formation and cell maturation by muscle-derived cells were unclear.
• Mechanical loading was hypothesized to modulate engineered tendon development.

Purpose of the Study:

• To investigate the role of mechanical loading in regulating the formation and maturation of muscle-derived cell-based engineered tendons.

Main Methods:

• Muscle-derived cells were seeded onto polyglycolic acid scaffolds.
• Cell-scaffold constructs were cultured in vitro, then implanted with or without dynamic mechanical loading.
• Histologic, ultrastructural, and biomechanical evaluations were performed at 12 and 24 weeks.

Main Results:

• Mechanical loading promoted the formation of mature neotendon tissue with organized collagen fibers and elongated cells.
• The non-loaded group formed disorganized fibrous tissue with inferior mechanical properties and collagen structure.
• Engineered tendon maturity increased with culture time under mechanical loading.

Conclusions:

• Mechanical loading is indispensable for successful tendon tissue engineering using muscle-derived cells.
• Muscle-derived cells show potential for neotendon regeneration, but require mechanical stimulation for optimal maturity.
• Stress deprivation leads to significantly inferior engineered tendon development and function.