Hydroxyapatite nanoparticle-modified porous bone grafts with improved cell attachment

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Nanotechnology

Background:

• Emulsion-templated foams show potential as injectable bone grafts.
• Surfactant emulsifiers limit pore size and hinder cell attachment.
• Hydroxyapatite nanoparticles offer an alternative stabilization method.

Purpose of the Study:

• To investigate hydroxyapatite nanoparticles as stabilizers for injectable bone graft foams.
• To improve cell attachment and pore architecture in bone graft materials.
• To develop a co-stabilization strategy using both nanoparticles and surfactants.

Main Methods:

• Modified hydroxyapatite nanoparticles with myristic acid to stabilize emulsions.
• Fabricated nanoparticle-stabilized and co-stabilized foams.
• Evaluated foam microarchitecture, pore size, and cell behavior (viability, attachment).
• Assessed co-stabilized foam as an injectable bone graft.

Main Results:

• Nanoparticle-stabilized foams showed significantly higher human mesenchymal stem cell viability (91%) compared to surfactant-stabilized foams (23%).
• Initial nanoparticle foams had appropriate pore size but lacked interconnectedness.
• Co-stabilized foams achieved large, interconnected pores (108 μm) with improved cell viability and attachment.
• Co-stabilized foams demonstrated favorable injectability and bone integration properties.

Conclusions:

• In situ surface modification with hydroxyapatite nanoparticles enhances cell attachment in bone graft foams.
• Co-stabilization with nanoparticles and surfactants optimizes pore architecture and cell response.
• The developed co-stabilized foam is a promising injectable bone graft material with improved biological and mechanical properties.