An injectable scaffold: rhBMP-2-loaded poly(lactide-co-glycolide)/hydroxyapatite composite microspheres

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HA) composite microspheres are investigated for bone tissue engineering applications.
• Surface modification of PLGA/HA microspheres is crucial for improving their biological performance.
• Osteogenic factors like recombinant human bone morphogenetic protein-2 (rhBMP-2) can enhance bone formation.

Purpose of the Study:

• To fabricate and characterize surface-treated PLGA/HA (50/50) composite microspheres.
• To evaluate the effect of surface treatment and rhBMP-2 loading on osteoblast response.
• To assess the potential of these microspheres as injectable scaffolds for bone regeneration.

Main Methods:

• Fabrication of PLGA/HA (50/50) composite microspheres.
• Surface treatment using a NaOH and ethanol mixture.
• Characterization of microsphere properties (surface roughness, HA content, hydrophilicity, degradation).
• Loading of rhBMP-2 onto treated microspheres.
• In vitro culture of mouse osteoblast-like cells (OCT-1) on microspheres.
• Assessment of cell attachment, proliferation, alkaline phosphatase activity, and differentiation.

Main Results:

• Surface treatment increased microsphere roughness, HA content, and hydrophilicity, with optimal treatment duration within 2 hours.
• Treated microspheres exhibited faster degradation in the initial 4 weeks compared to untreated ones.
• Surface-treated PLGA/HA microspheres significantly promoted osteoblast attachment, proliferation, and alkaline phosphatase activity.
• rhBMP-2 loaded onto treated microspheres showed sustained release and enhanced osteoblast differentiation.

Conclusions:

• Surface modification of PLGA/HA microspheres enhances their osteoconductivity and cell affinity.
• rhBMP-2 loaded on treated microspheres effectively promotes osteogenic potential.
• These rhBMP-2 loaded PLGA/HA composite microspheres are promising candidates for injectable bone scaffolds.