Development of polymeric microparticles for controlled release of bioactive drugs using modified solution enhanced dispersion by supercritical CO2

Poly (L-lactic acid) microparticles (PLLAms) loaded with growth factors were prepared through the modified (ethanol as the modifier) solution enhanced dispersion by supercritical CO2 (SEDS) for controlling release rate while maintaining bioactivity. Trypsin was used to explore operational parameters and their influence on release. Results showed that the optimized flow rate of polymer solution was 1.0 mL/min. Release rate of trypsin-PLLAms was regulated by molecular weight of PLLA and Polyethylene glycol (PEG) ratio. Bone morphogenetic protein (BMP-2), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor (VEGF) was loaded into PLLAms. Encapsulation efficiency was 65.9%, 63.9%, and 64.3%, cumulative release rate was 63.2%, 74.8% and 84.1% for 7 days, respectively. BMP-2, VEGF and FGF-2 released from PLLAms significantly promoted cell proliferation and differentiation. Therefore, the modified SEDS effectively maintained drug bioactivity, which could be used to fabricate carriers for controlled bioactive drugs release.

Automated summary

Poly(L-lactic acid) microparticles loaded with growth factors were prepared using modified SEDS method, which effectively controlled the release rate while maintaining bioactivity. This study demonstrated the potential of using these carriers for controlled release of bioactive drugs.