Tunable zero-order drug delivery systems created by modified triaxial electrospinning

The ability to accurately control a material's structure, and in turn its functional performance, is of crucial importance for potential applications. In this study, a new modified triaxial electrospinning process was successfully developed to allow us to precisely tune drug release from nanoscale formulations. In this process, we used two un-electrospinnable liquids as the outer and middle working fluids, with only the core solution being individually electrospinnable into fibers. The outer liquid comprised a mixture of solvents, while the middle fluid was a dilute solution of cellulose acetate (CA). The core fluid was an electrospinnable co-dissolving solution of ferulic acid (FA) and gliadin. By processing these in triaxial electrospinning, we were able to create FA-gliadin fibers coated with a thin but even and continuous coating of CA. The thickness of the CA coating could be precisely varied by adjusting the flow rate of the middle working fluid. The resultant nanofibers have linear and cylindrical morphologies with clear core-shell structures. X-ray diffraction and IR spectroscopy data verified that the fibers comprised amorphous solid dispersions, with intermolecular interactions existing between FA and gliadin. The CA coating eliminated the initial burst release seen with uncoated FA-gliadin fibers, and also led to close to zero-order release profiles which could be incrementally adjusted by varying the thickness of the coating. New process-nanostructure-performance relationships are therefore revealed, and the advanced triaxial electrospinning approach reported in this work has great potential for developing new kinds of functional nanomaterials.