Core-Sheath Nanofibers as Drug Delivery System for Thermoresponsive Controlled Release

Abstract

(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.

Relating Advanced Electrospun Fiber Architectures to the Temporal Release of Active Agents to Meet the Needs of Next-Generation Intravaginal Delivery Applications

“…At room temperature, poly( N -isopropylacrylamide) exhibits hydrophilic properties; however, at temperatures above 32 °C, the polymer demonstrates more hydrophobic characteristics. At room temperature and after 55 h, the fibers released 65% of ketoprofen in PBS, while only 40% of the same drug was released at 37 °C [104].…”

Core-Shell Nanostructures for Drug Delivery and Theranostics

“…In an approach aiming to produce thermoresponsive core-shell nanofibers, biomolecules were loaded in the core with a thermoresponsive polymer [85]. Thermoresponsive coaxial nanofibers were developed by using ketoprofen and PNIPAAm in the core and EC in the sheath (c-PNIPAAm-ketoprofen/s-EC nanofibers) [85]. It was seen that coaxial nanofibers were quite good at exhibiting both sustained and thermoresponsive release.…”

“…But c-PNIPAAm-ketoprofen/s-EC nanofibers were able to reduce this effect and combined thermoresponsive feature of PNIPAAm and sustained release ability of coaxial nanofibers. When the temperature increases from 25 C to 37 C, EC, which is in the sheath, tighten up and core nanofiber shrinks and in addition when the temperature goes back to 25 C nanofibers restore the original state [85].…”

Protein-Based Fiber Materials in Medicine: A Review

“…Fibrous materials, so often used in industrial applications and the textile industry, have now migrated into biomedical research. To date, polymer-based fibers with diameters on the micro- or nanoscale have been explored in drug delivery [ 1 , 2 , 3 , 4 ], wound healing [ 5 , 6 , 7 ], tissue engineering [ 8 , 9 , 10 ], and biosensor technologies [ 11 , 12 , 13 ] due to their high surface-area-to-volume ratio, mechanical strength, porosity, potential for surface modification, and tunability [ 13 , 14 , 15 ]. Equally important in biomaterials engineering, however, is the need for materials to be both biocompatible and biodegradable.…”