Bone scaffolds with homogeneous and discrete gradient mechanical properties.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Bone tissue engineering (TE) utilizes scaffolds to regenerate bone by inducing formation or serving as a template for cells.
• Native bone exhibits complex gradients in cellular and extracellular architecture and mechanical properties.

Purpose of the Study:

• To develop and characterize novel bone TE scaffolds using collagen, gelatin, and hydroxyapatite (HA).
• To investigate the mechanical properties and biocompatibility of these scaffolds.
• To create and evaluate discrete functionally graded scaffolds (FGSs) mimicking native bone's graded structure.

Main Methods:

• Scaffolds were fabricated using collagen, gelatin, and HA, cross-linked with genipin.
• Mechanical characterization included compression, swelling, and creep tests to derive viscoelastic models.
• Fabricated constructs were assessed for genipin and collagen release.
• Discrete FGSs were designed to mimic bone's graded architecture.
• Anisotropy of FGSs was mechanically evaluated.

Main Results:

• The fabricated scaffolds demonstrated no toxic release of collagen or genipin.
• Mechanical tests revealed an elastic behavior, with the compressive elastic modulus increasing with HA content and influenced by porosity and water content.
• Discrete FGSs exhibited marked anisotropy, similar to native bone tissue.
• The developed FGSs showed potential as bone substitutes.

Conclusions:

• Genipin-cross-linked collagen-gelatin-HA scaffolds are mechanically robust and biocompatible.
• Discrete FGSs effectively mimic the anisotropic and graded mechanical properties of native bone.
• These FGSs represent a promising advancement for bone tissue engineering applications.