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

Abstract

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.

Enzyme entrapment, biocatalyst immobilization without covalent attachment

“…Enzymes are covalently attached to a support material, often a commercial polymer, by providing reactive points on the polymer that anchor onto the protein. 73,74 For example, lipase A from Bacillus subtilis was immobilized via covalent modification of silica supported poly(sulfobetaine methacrylate) (PSBMA) polymer brushes. 75,76 The enzyme was bound to the polymer brush by covalent modification of lysine with an NHS group (N-hydroxysuccinimide).…”

pH-Responsive Electrospun Nanofibers and Their Applications

“…[163] Furthermore, the deposition of biocompatible polymers or biomolecules also provides more biologically compatible systems. [164] 4. Applications of pH-responsive nanofibers E-spun fiber materials that change their physicochemical properties upon pH change in their surrounding have gained large attention for various applications in the biomedical field, such as drug delivery, [165] and environmental fields, such as filtration [166] and sensors.…”

Preparation of Electrospun Small Intestinal Submucosa/Poly(caprolactone-co-Lactide-co-glycolide) Nanofiber Sheet as a Potential Drug Carrier

“…Various synthetic and natural materials can be used to fabricate electrospun NS [ 18 , 19 ]. Among the several options for materials, it was expected that electrospinning SIS would generate electrospun SIS nanofiber sheets (SIS-NS).…”