Electrospun Regenerated Cellulose Nanofibrous Membranes Surface-Grafted with Polymer Chains/Brushes via the Atom Transfer Radical Polymerization Method for Catalase Immobilization

Abstract

In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane with fiber diameters of ∼200-400 nm was prepared first; subsequently, 2-hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA), and acrylic acid (AA) were selected as the monomers for surface grafting of polymer chains/brushes via the atom transfer radical polymerization (ATRP) method. Thereafter, four nanofibrous membranes (i.e., RC, RC-poly(HEMA), RC-poly(DMAEMA), and RC-poly(AA)) were explored as innovative supports for immobilization of an enzyme of bovine liver catalase (CAT). The amount/capacity, activity, stability, and reusability of immobilized catalase were evaluated, and the kinetic parameters (Vmax and Km) for immobilized and free catalase were determined. The results indicated that the respective amounts/capacities of immobilized catalase on RC-poly(HEMA) and RC-poly(DMAEMA) nanofibrous membranes reached 78 ± 3.5 and 67 ± 2.7 mg g(-1), which were considerably higher than the previously reported values. Meanwhile, compared to that of free CAT (i.e., 18 days), the half-life periods of RC-CAT, RC-poly(HEMA)-CAT, RC-poly(DMAEMA)-CAT, and RC-poly(AA)-CAT were 49, 58, 56, and 60 days, respectively, indicating that the storage stability of immobilized catalase was also significantly improved. Furthermore, the immobilized catalase exhibited substantially higher resistance to temperature variation (tested from 5 to 70 °C) and lower degree of sensitivity to pH value (tested from 4.0 and 10.0) than the free catalase. In particular, according to the kinetic parameters of Vmax and Km, the nanofibrous membranes of RC-poly(HEMA) (i.e., 5102 μmol mg(-1) min(-1) and 44.89 mM) and RC-poly(DMAEMA) (i.e., 4651 μmol mg(-1) min(-1) and 46.98 mM) had the most satisfactory biocompatibility with immobilized catalase. It was therefore concluded that the electrospun RC nanofibrous membranes surface-grafted with 3-dimensional nanolayers of polymer chains/brushes would be suitable/ideal as efficient supports for high-density and reusable enzyme immobilization.

MOF‐Based Nanotubes to Hollow Nanospheres through Protein‐Induced Soft‐Templating Pathways

“…Generally, immobilization always results in an order of magnitude the change in the kinetic parameters compared to those of free enzymes. [3c,13] As seen in Table 1 , compared to free BCL, BCL@ZIF‐8 exhibited a sharp increase in K m (Michaelis–Menten constant) and decreases in both K cat (turnover number) and K cat / K m . Additionally, the slight decrease in the K cat value of BCL@H‐ZIF‐8 indicated a reduction in the affinity between BCL and the substrate molecules.…”

“…Additionally, the slight decrease in the K cat value of BCL@H‐ZIF‐8 indicated a reduction in the affinity between BCL and the substrate molecules. [13a] The increase in the apparent K m and the decrease in K cat / K m may be due to the mass transport resistance for substrates or products into and out of the hollow nanospheres . Furthermore, the slight change in K m and K cat also indicated that the conformation and structure of the BCL molecules were protected during the BCL@H‐ZIF‐8 construction process.…”

Superhydrophobic, Hybrid, Electrospun Cellulose Acetate Nanofibrous Mats for Oil/Water Separation by Tailored Surface Modification

“…20,21 For the modification of the CA nanofibrous mats, some specific grafting or modifying agents, such as glycidyl methacrylate-g-PEG for organic fouling prevention, 22 vinyltrimethoxysilane for selective gas permeation with CO 2 and H 2 S having reduced brittleness, 23 and poly[(ar-vinylbenzyl)trimethylammonium chloride)] [poly(VBTAC)] for the reusable nanomats by measuring the adsorption capacity targeting the separation of DNA, were used. 24 Additionally 2hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA) and acrylic acid for efficient supports for enzyme immobilization, 25 poly(N-isopropylacrylamide) for the responsive superhydrophobic electrospun nanofibrous mats, ZnO nanoparticles for optical properties have been studied and deeply analyzed. As expected −OH anchor groups act as the modification points but additionally ester groups or double bonds can be also used.…”

Modular and Versatile Spatial Functionalization of Tissue Engineering Scaffolds through Fiber‐Initiated Controlled Radical Polymerization

“…Polymer brush growth from electrospun fibers has typically been achieved using ATRP polymerization of a variety of different monomers. In most approaches that are directed towards biomedical applications, the initiating group is incorporated as a post electrospinning modification before polymerization has been undertaken 17, 18, 19, 20, 21, 22. Our strategy offers significant advantages to this by incorporating the initiator as an end‐group to the polymer prior to electrospinning to allow precise control over the spatial position of the functional groups without disrupting the fiber architecture.…”