Hydroxyapatite nanoparticle loaded collagen fiber composites: microarchitecture and nanoindentation study

Area of Science:

• Biomaterials Science
• Materials Engineering
• Nanotechnology

Background:

• Hydroxyapatite (HA) and collagen are key components in bone tissue.
• Developing HA/collagen composites is crucial for bone regeneration and repair.
• Controlling the composite's microarchitecture influences its mechanical properties.

Purpose of the Study:

• To prepare and characterize hydroxyapatite (HA) nanoparticle-collagen composite materials.
• To investigate the effect of varying HA/collagen weight ratios and microarchitectures on composite properties.
• To determine the optimal HA content for enhanced mechanical performance.

Main Methods:

• Preparation of HA/collagen composites via solution deposition and electrospinning techniques.
• Utilizing static or rotating collectors in electrospinning to influence fibrous structure.
• Characterization of composite structure, surface morphology, and nanoindentation properties.

Main Results:

• Achieved HA/collagen weight ratios of 80:20 (solution deposition) and up to 30:70 (electrospinning).
• Nanoindentation Young's modulus ranged from 0.2 GPa to 20 GPa, and hardness from 25 MPa to 500 MPa.
• Maximum mechanical properties (modulus and hardness) were observed at 45-60% HA content by weight.

Conclusions:

• Fabrication techniques significantly influence the achievable HA/collagen ratios and composite microarchitecture.
• The mechanical properties of HA/collagen composites are highly dependent on composition and fabrication method.
• HA/collagen composites with 45-60% HA content exhibit promising mechanical characteristics for biomaterial applications.