Annulus fibrosus tissue engineering using lamellar silk scaffolds

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Orthopedics

Background:

• Intervertebral disc (IVD) degeneration is a major cause of musculoskeletal disease.
• Current scaffolds for IVD regeneration lack the specific lamellar morphology of annulus fibrosus (AF) tissue.
• Restoring anatomical structure and biological/mechanical function is key for successful IVD regeneration.

Purpose of the Study:

• To investigate silk fibroin scaffolds with lamellar morphology for AF tissue regeneration.
• To compare the efficacy of lamellar silk scaffolds against porous silk scaffolds as controls.
• To assess the ability of scaffolds to support AF cell growth and extracellular matrix (ECM) production.

Main Methods:

• Fabrication of toroidal silk fibroin scaffolds with lamellar and porous morphologies.
• Seeding scaffolds with porcine AF cells and culturing in vitro.
• Histological analysis, biochemical assays, mechanical testing, and gene expression analysis.

Main Results:

• Lamellar silk scaffolds promoted superior ECM expression and tissue function compared to porous scaffolds.
• Porcine AF cells cultured on lamellar scaffolds maintained the native AF tissue shape.
• Histology, biochemistry, mechanical tests, and gene expression favored the lamellar scaffold for AF regeneration.

Conclusions:

• Lamellar silk scaffolds are effective in generating AF-like tissue in vitro.
• The lamellar architecture is crucial for mimicking native AF tissue structure and function.
• Silk fibroin offers a promising biomaterial for developing advanced IVD regeneration strategies.