Double-Layer Microsphere Incorporated with Strontium Doped Calcium Polyphosphate Scaffold for Bone Regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Drug Delivery Systems

Background:

• Skull defects pose significant challenges in reconstructive surgery.
• Current bone graft materials often have limitations in promoting complete and rapid bone regeneration.
• Developing advanced materials for controlled drug release is crucial for enhancing therapeutic outcomes.

Purpose of the Study:

• To design and fabricate a novel double-layer microsphere-based controlled release system for sustained drug delivery.
• To incorporate this system with a strontium-doped calcium polyphosphate (SCPP) scaffold for enhanced bone regeneration.
• To evaluate the efficacy of this composite material for skull repair.

Main Methods:

• Fabrication of double-layer microspheres loaded with tetracycline and matrix metalloproteinase-2 (MMP-2) using electrospinning.
• Adhesion of microspheres to SCPP scaffolds.
• Characterization of microstructure using scanning electron microscopy.
• In vitro assessment of drug loading, cytotoxicity, and effects on osteoblast proliferation and gene expression.
• In vivo evaluation of bone regeneration in rabbit skull defects.

Main Results:

• Successful fabrication of a double-layer microsphere system adhered to an SCPP scaffold.
• Optimized loading efficiencies and microsphere ratios were determined.
• In vitro studies demonstrated good biocompatibility and promotion of osteoblast activity.
• In vivo implantation in rabbit skull defects showed significant enhancement of bone regeneration.

Conclusions:

• The developed SCPP scaffold with dual-drug loaded microspheres represents a promising composite material for bone repair.
• This novel controlled release system effectively facilitates skull defect healing.
• Further research may lead to clinical applications in orthopedic and craniofacial reconstruction.