Fabrication and characterization of chitosan-polycaprolactone core-shell nanofibers containing tetracycline hydrochloride

Chitosan-polycaprolactone (CS-PCL) core-shell structured nanofibers, in which CS and PCL respectively form the core and shell layers, were electrospun by coaxial electrospinning method. In this regard, three sets of core-shell nanofiber samples were prepared and the best one with desirable morphology, smooth surface, and without beads was characterized. Then tetracycline hydrochloride (TCH) is embedded in the CS core. An attempt has been made to prove the formation of the core-shell structure and encapsulation of the drug by water contact angle (WCA) measurements and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR). Transmission electron microscopy (TEM) was also used for the validation of the core-shell structure. Morphological investigations were conducted using scanning electron microscopy (SEM) which showed smooth CS-PCL nanofibers without any beads and with an average diameter of 285±75 nm. Compositional analysis was carried out by differential scanning calorimetry (DSC) which indicated that about 64.3% of the prepared CS-PCL core-shell nanofibers were composed of PCL constituent. Also, In-vitro degradation of the nanofibers in the Phosphate Buffered Saline (PBS) solution was evaluated. In comparison to the blend nanofibers, TCH-loaded CS-PCL core-shell nanofibers showed a two-stage release of the drug, an initial burst release stage followed by a sustained release. Moreover, the antibacterial activity of CS-PCL core-shell nanofibers loaded with TCH was confirmed; hence, it has some potential applications in biomedical areas such as in wound dressing and drug delivery systems.