Coaxial Electrospinning of Protein-Encapsulated Core-Shell Nanofibers: Process Optimization and Release Modeling

Coaxial electrospinning is a novel method for encapsulation of protein drugs into polymeric materials for use in drug delivery systems. In this study, coaxial electrospinning was used to fabricate aligned polyethylene oxide/poly(lactic-co-glycolic acid) core-shell nanofibers encapsulated with nerve growth factor (NGF), a trophic agent for axonal regeneration. Electrospinning processing parameters, namely inner and outer flow rates, wheel speed, needle-wheel distance, and applied voltage, were optimized using design of experiment (DOE) methodology to achieve nanofibers with minimized diameter and size distribution. The resulting prediction models were validated using analysis of variance. Optimized fibers were incubated in phosphate-buffered saline (PBS) for 3 days, and the released NGF was characterized at different time points using ELISA. The NGF release profile was mathematically modeled utilizing the Korsmeyer-Peppas and zero-order models. The results of this study can be applied to drug delivery systems for neural regeneration.