Double-layered microsphere based dual growth factor delivery system for guided bone regeneration.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Microsphere drug delivery systems are valuable for tissue engineering.
• Controlled delivery of multiple growth factors remains a challenge.

Purpose of the Study:

• To develop double-layered microspheres for sequential release of SDF-1 and BMP-2.
• To evaluate their efficacy in bone regeneration.

Main Methods:

• Fabrication of double-layered microspheres with inner core and outer shell particles.
• In vitro release testing of SDF-1 and BMP-2.
• Cell migration assays (chemotaxis) on preosteoblasts.
• In vitro osteoinductive assays (ALP activity, mineralization).
• Gene expression analysis of bone development markers (Runx2, OCN, Osterix) and Smad signaling pathways.

Main Results:

• Achieved differential and sustained release of SDF-1 and BMP-2.
• Demonstrated enhanced preosteoblast migration towards microspheres.
• Observed significantly higher ALP activity and mineralized nodule formation.
• Showed increased expression of key bone development transcription factors and Smad signaling pathway components.

Conclusions:

• Double-layered microspheres effectively deliver multiple growth factors sequentially.
• This system promotes osteogenic cell recruitment and enhances osteoinduction.
• The developed microsphere platform shows significant promise for bone regeneration applications.