Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone) composite nanofibers

Next step in 2nd generation glucose biosensors: Ferrocene-loaded electrospun nanofibers

Glucose determination is one of the most common analyses in clinical chemistry. Employing biosensors for this purpose has become the method of choice for home use for diabetic patients. To limit the impact of dissolved O₂ concentration or possible interferences (known hindrances in the classical glucose detection approach), a variety of mediated pathways have been explored. Herein, an ingenious, facile and low-cost approach for immobilization of redox mediator within nanofibrous mats is presented. This '2^nd generation' biosensor is able to avoid common issues such as leaching or diffusion barriers whilst providing the necessary close contact between the enzyme and the redox shuttle, for enhancing the detection accuracy and accelerate the response. Polyacrylonitrile nanofibers loaded with carbon nanotubes and ferrocene (PAN/Fc/MWCNT-COOH NFs) have been successfully prepared and applied as biosensing matrices upon cross-linking of glucose oxidase (GOD). The morphology of the NFs was investigated by means of scanning electron microscopy (SEM-EDX) and correlated to the kinetics of mediated electron transfer and to the efficiency in glucose detection, which were evaluated through cyclic voltammetry (CV) and amperometric measurements. The content of Fc was varied from 0.5 to 5.0 wt%, with optimum biosensor performance at 1.0 wt% exhibiting a linear range up to 8.0 × 10^-3 M with sensitivity of ~27.1 mAM^-1 cm^-2 and 4.0 μM LOD. Excellent stability (RSD 2.68%) during 40 consecutive measurements along with insignificant interference and accurate recovery in real sample analysis (~100%) make for a very reliable sensor that can easily render itself to miniaturization and has the potential for a wide range of practical applications.

Synthesis, characterization, and antimicrobial properties of novel double layer nanocomposite electrospun fibers for wound dressing applications

Herein, novel hybrid nanomaterials were developed for wound dressing applications with antimicrobial properties. Electrospinning was used to fabricate a double layer nanocomposite nanofibrous mat consisting of an upper layer of poly(vinyl alcohol) and chitosan loaded with silver nanoparticles (AgNPs) and a lower layer of polyethylene oxide (PEO) or polyvinylpyrrolidone (PVP) nanofibers loaded with chlorhexidine (as an antiseptic). The top layer containing AgNPs, whose purpose was to protect the wound site against environmental germ invasion, was prepared by reducing silver nitrate to its nanoparticulate form through interaction with chitosan. The lower layer, which would be in direct contact with the injured site, contained the antibiotic drug needed to avoid wound infections which would otherwise interfere with the healing process. Initially, the upper layer was electrospun, followed sequentially by electrospinning the second layer, creating a bilayer nanofibrous mat. The morphology of the nanofibrous mats was studied by scanning electron microscopy and transmission electron microscopy, showing successful nanofiber production. X-ray diffraction confirmed the reduction of silver nitrate to AgNPs. Fourier transform infrared spectroscopy showed a successful incorporation of the material used in the produced nanofibrous mats. Thermal studies carried out by thermogravimetric analysis indicated that the PVP–drug-loaded layer had the highest thermal stability in comparison to other fabricated nanofibrous mats. Antimicrobial activities of the as-synthesized nanofibrous mats against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were determined using disk diffusion method. The results indicated that the PEO–drug-loaded mat had the highest antibacterial activity, warranting further attention for numerous wound-healing applications.

Antimicrobial electrospun poly(ε-caprolactone) scaffolds for gingival fibroblast growth

This study discusses the value of polymer electrospun materials in three-dimensional (3D) scaffolds and antibacterial wound dressings for potential dental applications.

Transmucosal delivery of Docetaxel by mucoadhesive polymeric nanofibers

The aim of the present study is to design a mucoadhesive nano-carrier system which retains at the site of application and maximizes the therapeutic potential of anticancer drug as well as reduces their systemic side effects. In the present study PVA nanofibers of Docetaxel were prepared using electrospinning machine. The resulting nanofibers were characterized through various parameters such as surface morphology, drug loading, in-vitro drug release, tensile strength, mucoadhesiveness, drug permeability, degree of swelling and anticancer activities against selective cell lines to establish their therapeutics potential. On the basis of various evaluation results, we may conclude that the current approach comprising polymeric nanofibers can be successfully used for local delivery of anticancer drug.