Topographical screening identifies optimal micropatterns for functional rat Achilles tendon regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Tendon injuries result in poor healing and functional deficits.
• Current treatments struggle to restore native tendon structure and function.
• Scaffold-based therapies offer potential for improved tendon regeneration.

Purpose of the Study:

• To evaluate the in vivo efficacy of polydimethylsiloxane (PDMS) scaffolds with varying micropatterns for Achilles tendon regeneration.
• To identify optimal surface parameters for enhanced functional tendon repair.
• To assess the impact of pit vs. column topography on healing outcomes.

Main Methods:

• Fabrication of six micropatterned PDMS scaffolds using photolithography.
• Implantation of scaffolds into a rat Achilles tendon injury model.
• Assessment of healing at 2 and 5 weeks via histology, gene expression (tendon markers, TGF-β1), and biomechanical testing.

Main Results:

• Pit scaffolds demonstrated superior outcomes compared to column scaffolds.
• The P-21-26 pit topography (21 μm diameter, 26 μm spacing) was identified as optimal.
• By week 5, P-21-26 scaffolds restored 93.7% of native tendon tensile strength, correlated with increased collagen density and reduced adhesion.
• Pit scaffolds promoted collagen deposition, reduced adhesions, and upregulated tenomodulin (Tnmd) and decorin (DCN).

Conclusions:

• Optimized surface topography, specifically 21 μm pits, significantly enhances functional Achilles tendon regeneration.
• This topography balances inflammation and fibrosis, leading to superior matrix organization and mechanical recovery.
• Surface topography is a critical design parameter for next-generation scaffolds, offering a translatable strategy for tendon repair.