Covalently coupled nanoparticles in capillary pores as enzyme carrier and as turbulence promoter to facilitate enzymatic polymerizations in flow-through enzyme–membrane reactors

Hicke, Hans‐Georg; Becker, Margot; Paulke, Bernd-Reiner; Ulbricht, Mathias

doi:10.1016/j.memsci.2006.05.051

Cited by 23 publications

(9 citation statements)

References 30 publications

(36 reference statements)

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“…[4] Track-etched membranes have been used for various surface functionalizations by 'grafting-from' or 'grafting-to' methods. [1,[5][6][7][8] In addition, the resulting porous composite membranes may directly find interesting applications, for examples, as an enzyme-membrane reactor [9,10] and a 'smart', i.e., stimuliresponsive porous membrane. [11,12] Therefore, as an example for extending the application of the novel method, the surface functionalization of track-etched PET with pores of %350 nm diameter by 'grafting-from' using the synergist immobilization method and the respective characterizations form the second part of this paper.…”

Section: Full Papermentioning

confidence: 99%

Synergist Immobilization Method for Photo‐Grafting: Factors Affecting Surface Selectivity

Ulbricht

2007

Macro Chemistry & Physics

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The surface‐selectivity of photo‐grafting has been used as a crucial parameter to evaluate the ‘grafting‐from’ efficiency of the synergist immobilization method developed in our recent work. The factors that affect surface‐selectivity of photo‐grafting have been further investigated. It was shown that the competition of solvent with the membrane surface towards the generation of starter radicals led to a decrease in the degree of grafting and surface‐selectivity of photo‐grafting. High UV intensity made the functionalization mechanism more complicated, due to the generation of a new type of starter radical at the membrane surface with immobilized synergist in the absence of BP and because it could lead to cross‐linking in the grafted layer. An appropriately low photo‐initiator concentration was also required in order to achieve the ideal surface‐selectivity of photo‐grafting. In addition, this method has been successfully applied to the track‐etched PET membranes. Pore size distributions as well as ethanol and water permeability of the membranes were used to retrieve information about the effective thickness of the grafted polymer layers.magnified image

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Section: Full Papermentioning

confidence: 99%

Synergist Immobilization Method for Photo‐Grafting: Factors Affecting Surface Selectivity

Ulbricht

2007

Macro Chemistry & Physics

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“…SR-PPMs are ideal materials for the creation of SR-PPMECs because of the following advantages: (i) many different types of monomers are commercially available, (ii) different PPMs that are charged or have various affinities or hydrophobic/hydrophilic properties can be prepared by versatile and robust methods, (iii) industrial-scale production is possible, and (iv) flat PPMs with tunable pore sizes, film thickness, and surface packing densities can be produced. ,,− Enzyme immobilization can be achieved by using different methods, including adsorption, entrapment, covalent bonding, and cross-linking, as shown in Figure . For the covalent binding of enzymes, presence or introduction of binding sites on the SR-PPMs is a prerequisite.…”

Section: Protocols For Creating Sr-ppmecsmentioning

confidence: 99%

“…5−8 Usually, enzyme carriers can be constructed by conjugation or direct attachment of enzymes onto the surface of different supports, including organic, inorganic, and hybrid nanoparticles 9−16 or flat polymer membranes (Figure 1A). 17,18 High mass transfer resistance, 19 external disturbance resistance, 5 and proteolytic degradation leading to obvious loss of enzyme effectiveness are the major disadvantages that discourage the use of these polymeric membrane-enzyme carriers, 20 but the attachment of enzymes to the porous polymer membranes (PPMs) can mitigate these problems (Figure 1B). 21,22 However, those traditional PPM-based enzyme carriers (PPMECs) have not focused on the key issue of regulating enzymolysis efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…They are popularly applied in industrial, biomedical, biochemical, and enzymatic engineering aspects . To improve the activity of enzymes and to decrease the cost of production, the immobilization of enzymes onto the different supports has gained significant attention in recent years. − This use of conjugated rather than free enzymes achieves the two major goals of enzyme stability and reusability. − Usually, enzyme carriers can be constructed by conjugation or direct attachment of enzymes onto the surface of different supports, including organic, inorganic, and hybrid nanoparticles − or flat polymer membranes (Figure A). , High mass transfer resistance, external disturbance resistance, and proteolytic degradation leading to obvious loss of enzyme effectiveness are the major disadvantages that discourage the use of these polymeric membrane-enzyme carriers, but the attachment of enzymes to the porous polymer membranes (PPMs) can mitigate these problems (Figure B). , However, those traditional PPM-based enzyme carriers (PPMECs) have not focused on the key issue of regulating enzymolysis efficiency. , Therefore, new smart PPMECs are still needed to achieve high convective mass transfer and protect the conjugated enzymes from proteolysis and external disturbance to ultimately realize controllable and efficient enzymolysis.…”

Section: Introductionmentioning

confidence: 99%

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Design of Switchable Enzyme Carriers Based on Stimuli-Responsive Porous Polymer Membranes for Bioapplications

Qiao

2021

ACS Appl. Bio Mater.

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Design of efficient enzyme carriers, where enzymes are conjugated to supports, has become an attractive research avenue. Immobilized enzymes are advantageous for practical applications because of their convenience in handling, ease of separation, and good reusability. However, the main challenge is that these traditional enzyme carriers are unable to regulate the enzymolysis efficiency or to protect the enzymes from proteolytic degradation, which restricts their effectiveness of enzymes in bioapplications. Enlightened by the stimuli-responsive channels in the natural cell membranes, conjugation of the enzymes within flat-sheet stimuli-responsive porous polymer membranes (SR-PPMs) as artificial cell membranes is an efficient strategy for circumventing this challenge. Controlled by the external stimuli, the multifunctional polymer chains, which are incorporated within the membranes and attached to the enzyme, change their structures to defend the enzyme from the external environmental disturbances and degradation by proteinases. Specifically, smart SR-PPM enzyme carriers (SR-PPMECs) not only permit convective substrate transfer through the accessible porous network, dramatically improving enzymolysis efficiency due to the adjustable pore sizes and the confinement effect, but they also act as molecular switches for regulating its permeability and selectivity. In this review, the concept of SR-PPMECs is presented. It covers the latest developments in design strategies of flat-sheet SR-PPFMs, fabrication protocols of SR-PPFMECs, strategies for the regulation of enzymolysis efficiency, and their cutting-edge bioapplications.

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“…[24][25][26] Recently, along with the rapid development in nano-science, nano-structured materials have emerged as supports for enzyme immobilization. [27][28][29][30][31] It has been demonstrated that the enzymes immobilized on the nano-structured materials have some advantages over the bulk solid substrates due to their large surface areas and good biocompatibility. Generally, surface modication or functionalization is required in order to efficiently immobilize enzymes onto the nano-structured materials, which could be a labored work and could reduce reproducibility and accuracy of enzyme assay.…”

Section: Introductionmentioning

confidence: 99%

A capillary electrophoresis-based immobilized enzyme reactor using graphene oxide as a support via layer by layer electrostatic assembly

Yin

Zhao

Tian

et al. 2014

Analyst

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A novel capillary electrophoresis (CE)-based immobilized enzyme reactor (IMER) using graphene oxide (GO) as a support was developed by using a simple and reliable immobilization procedure based on layer by layer electrostatic assembly. Using trypsin as a model enzyme, the performance of the fabricated CE-based IMERs was evaluated. Various conditions, including trypsin concentration, trypsin coating time, number of trypsin layers and buffer pH, were investigated and optimized. The Michaelis constant Km (0.24 ± 0.02 mM) and the maximum velocity Vmax (0.32 ± 0.04 mM s(-1)) were determined using the CE-based IMERs, and the values are consistent with those obtained using free trypsin, indicating that enzyme immobilized via the proposed approach does not cause a significant structural change of the enzyme or any reduction of enzyme activity. The presented CE-based IMERs exhibit excellent reproducibility with RSD less than 2.8% over 20 runs, and still remain 79.5% of the initial activity after five days with more than 100 runs. Using the proposed CE-based IMERs, the digestion of angiotensin was completed within 3 min, while quite a number of trypstic peptides were observed for BSA on-line digestion with an incubation time of 30 min. As identified by MS analysis, the online digestion products of BSA using the present CE-based IMER are comparable with those obtained using free trypsin digestion for 12 h incubation. It is indicated that the present immobilization strategy using GO as a support is reliable and practicable for accurate on-line analysis and characterization of peptides and proteins.

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Covalently coupled nanoparticles in capillary pores as enzyme carrier and as turbulence promoter to facilitate enzymatic polymerizations in flow-through enzyme–membrane reactors

Cited by 23 publications

References 30 publications

Synergist Immobilization Method for Photo‐Grafting: Factors Affecting Surface Selectivity

Synergist Immobilization Method for Photo‐Grafting: Factors Affecting Surface Selectivity

Design of Switchable Enzyme Carriers Based on Stimuli-Responsive Porous Polymer Membranes for Bioapplications

A capillary electrophoresis-based immobilized enzyme reactor using graphene oxide as a support via layer by layer electrostatic assembly

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