Intervertebral Disc Tissue Engineering with Natural Extracellular Matrix-Derived Biphasic Composite Scaffolds

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Degenerative disc diseases lack ideal tissue engineering scaffolds.
• Intervertebral disc (IVD) tissue engineering offers a therapeutic alternative.
• Novel biomimetic scaffolds are crucial for successful IVD regeneration.

Purpose of the Study:

• To fabricate a novel biomimetic biphasic scaffold for IVD tissue engineering.
• To evaluate the feasibility of developing tissue-engineered IVD in vitro and in vivo.
• To assess the potential of bone matrix gelatin and acellular cartilage ECM for IVD repair.

Main Methods:

• Developed an integrated biphasic scaffold using freeze-drying and cross-linking of pig bone matrix gelatin (BMG) for annulus fibrosus (AF) and pig acellular cartilage ECM (ACECM) for nucleus pulposus (NP).
• Characterized scaffold microstructure (pore size) using SEM and confirmed absence of residual cells.
• Seeded PKH26-labeled AF and NP cells, cultured in vitro, and implanted constructs subcutaneously into nude mice for 6 weeks.

Main Results:

• Scaffold exhibited interconnected porous microstructure (AF: 401.4 ± 13.1 μm, NP: 231.6 ± 57.2 μm).
• In vitro studies confirmed cell adhesion and viability.
• In vivo implantation resulted in the formation of IVD-like tissue, with cells originating from labeled cells tracked via fluorescence imaging.

Conclusions:

• Demonstrated the feasibility of developing a tissue-engineered IVD in vivo using a BMG- and ACECM-derived biphasic scaffold.
• PKH26 fluorescent labeling and in vivo imaging are effective for tracking cells and analyzing cell-scaffold constructs.
• This approach holds promise for treating degenerative disc diseases.