Hydroxyapatite fiber reinforced poly(alpha-hydroxy ester) foams for bone regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Biodegradable composite foams are crucial for bone regeneration applications.
• Poly(DL-lactic-co-glycolic acid) (PLGA) and hydroxyapatite (HA) are promising biomaterials for bone scaffolds.
• Controlling foam porosity and mechanical properties is essential for effective tissue engineering.

Purpose of the Study:

• To develop a manufacturing process for biodegradable composite foams of PLGA and hydroxyapatite short fibers.
• To investigate the effect of hydroxyapatite fiber reinforcement on foam properties.
• To create tunable scaffolds for bone regeneration with controlled porosity and mechanical strength.

Main Methods:

• Utilized a porogen leaching technique (gelatin microspheres or salt particles) to create open-cell structures.
• Embedded hydroxyapatite short fibers within a PLGA matrix.
• Varied the weight fraction of the porogen and the polymer:fiber ratio to control porosity and mechanical properties.

Main Results:

• Achieved controlled porosities ranging from 0.47 to 0.85.
• Low-porosity foams (0.47) reinforced with hydroxyapatite fibers exhibited enhanced compressive yield strength up to 2.82 MPa.
• High-porosity foams (up to 0.81) suitable for cell seeding showed no significant reinforcement from hydroxyapatite fibers.

Conclusions:

• Successfully manufactured biodegradable composite foams with tunable porosity and mechanical properties.
• Demonstrated that hydroxyapatite fiber reinforcement is effective for low-porosity, high-strength scaffolds.
• Developed versatile scaffolds for bone regeneration, offering options for high cell seeding capacity or enhanced mechanical integrity.