Customised multiphasic nucleus/annulus scaffold for intervertebral disc repair/regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Spinal fusion for degenerated intervertebral discs (IVDs) shows short-term success but long-term spinal instability.
• Existing IVD prostheses have limitations, and tissue engineering faces challenges due to IVD complexity.

Purpose of the Study:

• To design customized multiphasic nucleus/annulus scaffolds for IVD tissue engineering.
• To leverage reverse engineering, additive manufacturing, and gel technologies for scaffold development.

Main Methods:

• Constructed a customized poly(ε-caprolactone) scaffold (annulus) via additive manufacturing.
• Developed a cell-laden nucleus using collagen-hyaluronic acid hydrogel with specific rheological properties.
• Assessed hydrogel injectability, viscoelasticity, and scaffold mechanical/biological properties.

Main Results:

• The hydrogel exhibited shear-thinning behavior, enabling injection.
• Scaffold's compressive modulus matched that of lumbar discs, showing a natural IVD-like stress-strain curve.
• Preliminary biological tests confirmed human mesenchymal stem cell viability.

Conclusions:

• The developed multiphasic scaffolds possess appropriate viscoelastic and mechanical characteristics for IVD regeneration.
• The combination of additive manufacturing and advanced hydrogels offers a viable strategy for customized IVD tissue engineering.
• These findings support the potential of the developed scaffolds as an alternative to current treatments for degenerated IVDs.