(LMZ); a.bligh@westminster.ac.uk (SWAB).
AbstractThermoresponsive, polymer-based core-sheath nanofibres are of great interest as advanced materials because they are capable of responding to external stimuli and delivering drugs as part of release strategy. Core-sheath nanofibers were constructed by using thermoresponsive poly-(N-isopropylacrylamide) (PNIPAAm) (as core) and hydrophobic ethylcellulose (EC) (as sheath) by coaxial electrospinning. Analogous medicated nanofibers were prepared by loading with a model drug ketoprofen (KET).The fibers were cylindrical without phase separation and have visible core-sheath structure as shown by scanning and transmission electron microscopy. X-ray diffraction patterns demonstrated the drug with the amorphous physical form was present in the fiber matrix. Fourier transform infrared spectroscopy analysis was conducted, finding that there were significant intermolecular interactions between KET and the polymers. Water contact angle measurements proved that the hydrophilic hydrophobic transformation of core-sheath fibers had taken place when the temperature reached the lower critical solution temperature. In vitro drug-release study of nanofibers with KET displayed that the coaxial nanofibers were able to synergistically combine the characteristics of the two polymers producing a temperature-sensitive drug delivery system with sustained release properties. In addition, they were established to be non-toxic and suitable for cell growth. These findings show that the core-sheath nanofiber is a potential candidate for controlled drug delivery system.