Controlled release of ampicillin from coxially electrospun polycaprolactone nanofibers

Controlled release of hydrophilic biological agents is difficult to be achieved with conventional approaches such as single electrospinning. One recent approach for controlled release is production of core-shell fibers via modified coaxial electrospinning. In this study, the application area of this technique was expanded by using it for a hydrophilic drug (ampicillin) which is known to have low compatibility with polycaprolactone (PCL). A partially electrospinnable 4% (w/v) PCL solution was used as a shell fluid in order to create ampicillin-loaded PCL nanofibers shelled by a PCL shield. Scanning electron microscopy and optical microscopy verified that the membranes consisted of nanofibers with core-shell structure. Furthermore, Fourier transform infrared spectroscopy demonstrated that some compatibility might be present between ampicillin and PCL. Finally, drug release studies showed that the drug release kinetics of core-shell products is closer to zero-order kinetics as compared to the products of single electrospinning. Together, these imply that the application area of modified electrospinning in controlled release could be expanded to polymers and drugs with low compatibility.