LBL deposition of chitosan/heparin bilayers for improving biological ability and reducing infection of nanofibers

The complexity of cardiovascular disease requires that the materials for preparing vascular grafts possess good biocompatibility, high mechanical property, and even some excellent additional properties. In this study, polycaprolactone (PCL) with good mechanical property and natural source silk fibroin (SF) were electrospun into PCL/SF nanofibers to obtain the nanofibrous substrate. With the addition of SF, the mechanical property of PCL/SF nanofibrous mats was maintained to a certain extent. While, the hydrophilicity of PCL/SF nanofibrous mats was greatly improved which is more suitable for immersive layer-by-layer assembly (LBL). The oppositely charged heparin (Hep) and chitosan (CS) were alternatively deposited on the surface of PCL/SF nanofibers via LBL. After implanting human umbilical vein endothelial cells (HUVEC) on the LBL-structured nanofibrous mats for 48 h, it was confirmed that the CS/Hep bilayers enhanced the biocompatibility of the nanofibers. Furthermore, the results of the antibacterial test showed that the antibacterial effects of the LBL-structured nanofibrous mats for Escherichia coli and Staphylococcus aureus were both achieved 95% when the number of Hep/CS bilayer was 10. It can be demonstrated that the LBL-structured nanofibrous mats with improved biocompatibility and reduced infectivity had been prepared successfully, and can be potentially used in vascular grafts.

A non-enzymatic glucose sensor based on electrospun 3-D copper oxide micro-nanofiber network films using carboxylic-functionalized poly(arylene ether ketone)s as templates

3-D network films of rope-like CuO-MNFs with high surface-to-volume ratio were prepared. The product is a promising electrode material for fabrication of amperometric enzymeless glucose sensors.

Electrospun porous hybrid CuO/CdO nanofibers using carboxylic-functionalized poly(arylene ether ketone)s as a template for glucose determination

As a high performance polymer, PCA-poly(arylene ether ketone) (PAEK) was first used as a template to fabricate hybrid copper oxide (CuO)/cadmium oxide (CdO) nanofibers (NFs) via electrospinning and subsequent calcination. Porous NFs with a mean diameter of 463 nm were obtained. The formation of morphology was decided by the ion exchange reaction between the functional groups on polymer template and metal ions, which was proved by Fourier transform infrared spectra. Energy-dispersive X-ray spectrometer and X-ray powder diffractometry spectra demonstrated the obtained substance was CuO/CdO compound. The products were then investigated in detail for direct electrocatalytic oxidation of glucose, which was evaluated by cyclic voltammetry and chronoamperometry. Results revealed a similar anti-interference, higher sensitive, and faster response of glucose than the fibers produced from traditional template at +0.40 V. The improved performances were ascribed to the porous morphology which increased the surface-to-volume ratio. The porous morphology was found to be decided by the immobilization of metal ions onto PCA-PAEK. In conclusion, the functional group on PCA-PAEK side chain was the decisive factor to prepare CuO/CdO NFs with special morphology and good electrooxidation performances.

Highly aligned magnetic composite nanofibers fabricated by magnetic-field-assisted electrospinning PAN/FeCo solution

Composite nanofiber meshes of well-aligned polyacrylonitrile (PAN)/FeCo nanofibers containing nanoparticles (NPs) were successfully fabricated by a magnetic-field-assisted electrospinning technology, which was confirmed to be a favorable method for the preparation of aligned composite nanofibers in this article. Meanwhile, FeCo NPs, with a particle size of approximately 60 nm, were synthesized using a hydrothermal route. The nanocomposite fibers were prepared by an electrospun solution of PAN containing 0, 2, 4, and 6 wt% NPs. The as-spun nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. Both the diameters and the degree of alignment of the composite nanofibers decreased with the increase in voltage and increased with the increase in FeCo content. The composite nanofibers exhibited superior ordered performance, with the highest alignment value being 97%. Due to the highly ordered alignment structures, the composite nanofiber meshes showed large anisotropic magnetic property. In particular, the saturation magnetization of the composite nanofiber films in the parallel and perpendicular directions of the fiber axis were 42 emu/g and 19.5 emu/g, respectively. Meanwhile, the remanence also exhibited distinction in different directions (parallel: 2.01 emu/g; perpendicular: 0.86 emu/g).