Emulsion-based synthesis of polycaprolactone/bioactive glass 45S5 microparticles for bone regeneration applications

Polycaprolactone (PCL) and bioactive glass 45S5 (BG) are widely employed within bone tissue engineering due to their mutually complementary properties: PCL contributes structural integrity and biodegradability, whereas BG imparts osteoinductive properties to the composite. While patient-specific bulk scaffolds can restore structural defects, their fabrication requires individualized imaging, design, and manufacturing, increasing both time and cost. Hydrogels offer better conformity to irregular geometries but often lack sufficient mechanical stability and usually degrade rapidly. Microparticle-based systems represent a shape-adaptive alternative that can conform to complex defect geometries without customization, while maintaining structural integrity. In this study, PCL/BG microparticles (MPs) were fabricated using the emulsion solvent evaporation method and evaluated in vitro. The microparticles supported adhesion and spreading, maintaining cell-cell and cell-particle interactions for over a month. Periosteum mesenchymal stem cells (PMSCs) cultured on the MPs were responsive to adipogenic and osteogenic induction, as evidenced by increased expression of lineage-specific genes under both conditions. Overall, these findings suggest that PCL/BG microparticles are biocompatible and capable of guiding stem cell differentiation, supporting their potential use in bone regeneration strategies.