Sustained drug release and antibacterial activity of ampicillin incorporated poly(methyl methacrylate)–nylon6 core/shell nanofibers

In vitro drug release mechanism of core/shell nanofibers of poly(methyl methacrylate)(PMMA)–nylon6 fabricated through coaxial electrospinning containing different concentrations of ampicillin was investigated. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Korsmeyer–Peppas equation and Fickian diffusion model were utilized to characterize the system. Antibacterial activity of the designed drug delivery system was investigated against Gram-positive Listeria innocua through optical density (OD) measurement. The system showed sustained drug release through three stages; although the release in stage I followed non-Fickian diffusion, Fickian diffusion was proven to be the release mechanism of stages II and III. A significant decrease in the diffusion coefficient from stage II to stage III was observed, which is believed to be the consequence of crystallization of fibers as a result of long-term incubation in an aqueous solution. Finally, the antibacterial activity of the system was verified by means of optical density (OD) measurements against Gram-positive L. innocua.