Cellular forces and matrix assembly coordinate fibrous tissue repair

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Cell Biology

Background:

• Planar in vitro models are limited in recapitulating 3D fibrous tissue repair.
• Existing models do not fully capture the rebuilding of complex tissue architecture during wound healing.

Purpose of the Study:

• To develop and validate a 3D biomimetic model for soft tissue repair.
• To elucidate the mechanical and cellular mechanisms driving 3D wound closure in fibrous tissues.

Main Methods:

• Development of a 3D collagen matrix model with fibroblasts.
• Microsurgical induction of defects in the 3D model.
• Application of traction force microscopy and time-lapse imaging.

Main Results:

• Fibroblasts within a collagen matrix rapidly closed defects within 24 hours.
• Wound closure initiated with contractility-mediated tissue deformations.
• Tangential fibroblast migration and fibronectin assembly formed a new matrix template for closure.

Conclusions:

• The 3D model effectively mimics soft tissue repair, revealing novel closure mechanisms.
• Stromal closure involves coordinated tissue deformation, matrix assembly, and cell migration.
• This mechanism differs from previously described lamellipodial and purse-string models, highlighting a new understanding of 3D tissue restoration.