Engineered Microenvironmental Cues from Fiber-Reinforced Hydrogel Composites Drive Tenogenesis and Aligned Collagen...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Tendon injuries require effective regeneration, focusing on cell differentiation and aligned matrix deposition.
• Biomaterials offer biochemical and physical cues to guide tenogenesis and prevent scar tissue formation.
• Fiber-reinforced hydrogels are promising for tendon regeneration due to injectability, tunable stiffness, and modularity.

Purpose of the Study:

• To investigate microenvironmental factors influencing tenogenesis and aligned collagen deposition.
• To explore the role of transforming growth factor beta 3 (TGF-β3) in cell fate.
• To assess the impact of hydrogel stiffness and topographical cues on tendon progenitor cells.

Main Methods:

• Utilized tunable, modular, fiber-reinforced synthetic hydrogels.
• Cultured tendon progenitor cells within these hydrogels under varying conditions.
• Manipulated transforming growth factor beta 3 (TGF-β3) signaling and RhoA/ROCK activity.
• Assessed cell differentiation, matrix deposition, and collagen alignment.

Main Results:

• TGF-β3 can bias cell fate towards regenerative or fibrotic phenotypes.
• Softer microenvironments and RhoA/ROCK inhibition promote a pro-regenerative cell fate.
• Topographical anisotropy in hydrogels is critical for aligning newly deposited collagen fibrils.
• Achieved alignment of de novo collagen fibrils mimicking native tendon architecture.

Conclusions:

• Microenvironmental factors like stiffness and topographical cues are key determinants of tendon regeneration.
• Injectable, cell-free, fiber-reinforced hydrogels can be designed for effective tendon tissue repair.
• Findings have implications for regenerating load-bearing connective tissues beyond tendons.