Preparation and characterization of electrospun poly(lactic acid)-chitosan core-shell nanofibers with a new solvent system

Poly(lactic acid)-chitosan (PLA-CS) core-shell nanofibers were successfully fabricated by coaxial electrospinning technique using a new solvent system for the core and shell solutions, dimethylformamide for the core solution and trifluoro-acetic acid/acetic acid (90/10 v/v) for the shell solution. The formation of the core-shell structure of the nanofibers with this new solvent system was confirmed by transmission electron microscopy (TEM) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR). Morphology of the as-spun nanofibers was investigated by scanning electron microscopy (SEM) which showed bead-free smooth PLA-CS core-shell type nanofibers with an average diameter of 671 +/- 172 nm and a broad diameter distribution. Thermogravimetric analysis (TGA) indicated that although PLA content was less than CS in the core-shell nanofibrous mat (20.7% PLA vs. 39% CS) the presence of PLA in the core of nanofibers significantly improved their mechanical properties. The PIA-CS core-shell nanofibers showed a two-stage release behavior of curcumin drug; an initial burst release followed by a sustained release, when the drug was incorporated in the core layer of nanofibers; hence it has potential applications in some biomedical areas such as wound dressing and drug delivery. (C) 2019 Elsevier B.V. All rights reserved.