Fabrication and characterization of black seed oil-loaded poly(lactic-co-glycolic acid)/pullulan nanofibers for...

The intrinsically slow and insufficiently tunable degradation kinetics of poly(lactic-co-glycolic acid) (PLGA) limit its versatility in medium-term biomedical delivery systems. Herein, we reported a one-step electrospinning strategy to establish a PLGA/pullulan (PUL) nanofibrous platform with regulated degradation behavior and sustained release capability, using black seed oil (BSO) as a model hydrophobic bioactive compound. The PLGA/PUL-BSO nanofibers exhibited uniform bead-free morphology. The specific surface area increased from 23.27 m2/g for PLGA/PUL nanofibers to 36.82 m2/g for PLGA/PUL-BSO nanofibers. Total porosity of the PLGA/PUL nanofibers decreased from 32% to 21% after BSO incorporation. The PLGA/PUL-BSO nanofibers degraded via bulk-erosion. An initial lag phase was observed during the first 8 days, followed by a rapid mass-loss phase between days 8 and 12. Subsequently, the mass loss gradually reached 77.1 ± 1.85% after 30 days. BSO release exhibited a two-stage release profile. The cumulative release reached 60.1 ± 3.9% within the first 6 h, consistent with a diffusion-controlled mechanism described by the Korsmeyer-Peppas model. Thereafter, during the sustained release phase, the cumulative release reached 76.3 ± 5.8% after 30 days and followed zero-order kinetics. Swelling equilibrium (%) of the PLGA/PUL-BSO nanofibers was significantly higher than that of PLGA/PUL nanofibers, demonstrating that BSO incorporation influenced the nanoscale organization of PLGA and PUL. Consequently, PUL addition effectively regulated the degradation properties of PLGA and modulated therapeutic release, demonstrating that the developed PLGA/PUL-BSO nanofibers constituted a robust nanofibrous materials platform with biomedical potential.