Covalent immobilization of β-galactosidase onto electrospun nanofibers of poly (AN-co-MMA) copolymer

Optimization and efficacy studies of Laccase immobilized on Zein-Polyvinyl pyrrolidone nano fibrous membrane in decolorization of Acid Red 1

Azo dyes are widely used in textile industries. A significant portion of these recalcitrant dyes are being discharged to the natural waters. Due to their low biodegradability they pose serious pollution problems if untreated. In this work, decolourization studies of Acid Red 1 (AR1) by laccase enzyme immobilized onto zein-polyvinyl pyrrolidone (PVP) composite nanofiber is done. The nanofibers were characterized by scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) analysis. pH and temperature profiles of immobilized enzyme were found to be broader than its free counterpart. The K_m value was found to be 0.243 mM for free laccase and 0.958 mM for immobilized laccase. Similarly, V_max for the free enzyme was 3.572 U/mg compared to 2.48 U/mg of immobilized laccase. The relative activity of immobilized laccase was 64.91% after storage for 30 days at room temperature while it was 28.64% for free laccase. The temperature and pH for AR 1 decolorization were optimized and was found to be 60 °C and 5, respectively. Also, decolorization percentage was found to be 91.67% for immobilized laccase and 72.03% of free laccase in the presence of natural mediators like vanillin. From phytotoxicity studies it was found that the germination rate, shoot and root length was increased compared to untreated dye. Therefore, zein-PVP nanofiber immobilized laccase could be an ideal candidate for the textile dye decolorization.

A Comprehensive Review of the Covalent Immobilization of Biomolecules onto Electrospun Nanofibers

Biomolecule immobilization has attracted the attention of various fields such as fine chemistry and biomedicine for their use in several applications such as wastewater, immunosensors, biofuels, et cetera. The performance of immobilized biomolecules depends on the substrate and the immobilization method utilized. Electrospun nanofibers act as an excellent substrate for immobilization due to their large surface area to volume ratio and interconnectivity. While biomolecules can be immobilized using adsorption and encapsulation, covalent immobilization offers a way to permanently fix the material to the fiber surface resulting in high efficiency, good specificity, and excellent stability. This review aims to highlight the various covalent immobilization techniques being utilized and their benefits and drawbacks. These methods typically fall into two categories: (1) direct immobilization and (2) use of crosslinkers. Direct immobilization techniques are usually simple and utilize the strong electrophilic functional groups on the nanofiber. While crosslinkers are used as an intermediary between the nanofiber substrate and the biomolecule, with some crosslinkers being present in the final product and others simply facilitating the reactions. We aim to provide an explanation of each immobilization technique, biomolecules commonly paired with said technique and the benefit of immobilization over the free biomolecule.

Polyethylenimine: a very useful ionic polymer in the design of immobilized enzyme biocatalysts

This review discusses the possible roles of polyethylenimine (PEI) in the design of improved immobilized biocatalysts from diverse perspectives.

Electrospun Polyvinyl Alcohol/ Pluronic F127 Blended Nanofibers Containing Titanium Dioxide for Antibacterial Wound Dressing

In this study, an antibacterial electrospun nanofibers for wound dressing application was successfully prepared from polyvinyl alcohol (PVA), Pluronic F127 (Plur), polyethyleneimine (PEI) blend solution with titanium dioxide nanoparticles (TiO2 NPs). PVA-Plur-PEI nanofibers containing various ratios of TiO2 NPs were obtained. The formation and presence of TiO2 in the PVA-Plu-PEI/ TiO2 composite was confirmed by X-ray diffraction (XRD). Transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), mechanical measurement, and antibacterial activity were undertaken in order to characterize the PVA-Plur-PEI/TiO2 nanofiber morphology and properties. The PVA-Plu-PEI nanofibers had a mean diameter of 220 nm, and PVA-Plur-PEI/TiO2 nanofibers had 255 nm. Moreover, the antimicrobial properties of the composite were studied by zone inhibition against Gram-negative bacteria, and the result indicates high antibacterial activity. Results of this antibacterial testing suggest that PVA-Plur-PEI/TiO2 nanofiber may be effective in topical antibacterial treatment in wound care; thus, they are very promising in the application of wound dressings.

Reactive and ‘clickable’ electrospun polymeric nanofibers

This mini-review summarizes the design, synthesis and modification of various reactive and ‘clickable’ electrospun polymeric nanofibers to render them functional.

Biologically inspired nanofibers for use in translational bioanalytical systems

Electrospun nanofiber mats are characterized by large surface-area-to-volume ratios, high porosities, and a diverse range of chemical functionalities. Although electrospun nanofibers have been used successfully to increase the immobilization efficiency of biorecognition elements and improve the sensitivity of biosensors, the full potential of nanofiber-based biosensing has not yet been realized. Therefore, this review presents novel electrospun nanofiber chemistries developed in fields such as tissue engineering and drug delivery that have direct application within the field of biosensing. Specifically, this review focuses on fibers that directly encapsulate biological additives that serve as immobilization matrices for biological species and that are used to create biomimetic scaffolds. Biosensors that incorporate these nanofibers are presented, along with potential future biosensing applications such as the development of cell culture and in vivo sensors.