Tailored sequential drug release from bilayered calcium sulfate composites

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Drug Delivery Systems

Background:

• Treating infected bony defects requires multiple procedures, increasing patient recovery time.
• Current treatments for bone defects are often time-consuming and involve multiple surgical interventions.
• A streamlined approach using synthetic bone graft substitutes could improve treatment efficiency.

Purpose of the Study:

• To develop tailorable, bilayered calcium sulfate (CS) bone graft substitutes capable of sequential drug release.
• To investigate the fabrication and properties of CS bone graft substitutes with embedded therapeutic agents.
• To assess the potential for a simplified treatment of infected bony defects.

Main Methods:

• Fabrication of bilayered CS composite samples with metronidazole-loaded poly(lactic-co-glycolic acid) (PLGA) particles and simvastatin.
• Characterization using microcomputed tomography, dissolution studies, and mechanical testing.
• Evaluation of sequential drug release kinetics based on layered geometry and PLGA content.

Main Results:

• Layered geometry and PLGA content (1 vs. 10 wt.%) influenced erosion rates and mechanical strength.
• Mechanical properties were comparable to mandibular trabecular bone.
• Sequential release of metronidazole and simvastatin was achieved by controlling drug loading and layer volume ratios.

Conclusions:

• Tunable, bilayered CS bone graft substitutes can be fabricated for sequential release of multiple therapeutic agents.
• This approach offers a potential method to streamline the treatment of infected bony defects.
• Tailored CS-based substitutes could reduce the number of surgical procedures and shorten patient recovery.