Smart carrier from electrospun core-shell thermo-sensitive ultrafine fibers for controlled drug release

Abstract In this study, electrospun core-shell thermo-sensitive (CSTS) ultrafine fibers were prepared successfully. The optimum structural polyethersulfone (PES) porous ultrafine fibers were chosen as core fabricated by electrospinning technology. In addition, in order to improve the lower critical solution temperature (LCST) of poly (N-isopropylacrylamide) (PNIPAm), acrylamide (Am) was chosen as the comonomer with excellent hydrophilicity and structural similarity to N-isopropylacrylamide. Thus, poly(N-isopropylacrylamide-co-acrylamide) P(NIPAm-co-Am) with higher LCST (LCST = 43 °C) was synthesized on the surface of PES fibers via radical copolymerization as shell. The introduction of the P(NIPAm-co-Am) influenced the morphology and performance of the PES ultrafine fibers significantly. Meanwhile, SEM, FTIR and XPS results all showed the P(NIPAm-co-Am) covered on the surface of PES fibers after polymerization for 4 h. Both the contact angle and shape change test indicated that the CSTS ultrafine fibers exhibited different wettability and area when the temperature was below and above the LCST due to the thermo-sensitive of P(NIPAm-co-Am) gels shell. Furthermore, curcumin was selected to use as drug model loaded in CSTS ultrafine fibers and the curcumin release behavior was tested to study the thermo-sensivity of CSTS ultrafine fibers. At 20 °C and 60 °C, the max curcumin release amount is w 33.21% and w 80.15%, respectively. The result directly demonstrated that CSTS ultrafine fibers had thermo-sensity as drug carrier. Finally, the cell culture studies showed that the prepared CSTS ultrafine fibers have a potential application in the biomedical fields.