Dynamic Electrochemical Membranes for Continuous Affinity Protein Separation

Chen, Zhiqiang; Chen, Tao; Sun, Xingsheng; Hinds, Bruce J.

doi:10.1002/adfm.201303707

Cited by 20 publications

(21 citation statements)

References 29 publications

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“… 39 With this geometry GT 1 (the first GT as shown in Figure 3 ), the 10 nm pore entrance will block the pore, thus excess solution GT 1 cannot pass through the pore to the other side of the AAO membrane after binding. 38 This allows a second distinct enzyme, GT 2 , to be immobilized on the 200 nm pore side of the AAO membrane to enable a directional sequential series of reactions. The process for N -His 6 -OleD immobilization on a gold surface ( Figure 2 ) enabled immobilization of a total amount of 30 μg of enzyme per monolayer coating based upon Bradford assay to afford a surface “concentration” of 3 g/mL immobilized enzyme within the 9.8 × 10 –6 mL electrode volume.…”

Section: Resultsmentioning

confidence: 99%

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

et al. 2014

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A nanoporous membrane system with directed flow carrying reagents to sequentially attached enzymes to mimic nature’s enzyme complex system was demonstrated. Genetically modified glycosylation enzyme, OleD Loki variant, was immobilized onto nanometer-scale electrodes at the pore entrances/exits of anodic aluminum oxide membranes through His6-tag affinity binding. The enzyme activity was assessed in two reactions—a one-step “reverse” sugar nucleotide formation reaction (UDP-Glc) and a two-step sequential sugar nucleotide formation and sugar nucleotide-based glycosylation reaction. For the one-step reaction, enzyme specific activity of 6–20 min−1 on membrane supports was seen to be comparable to solution enzyme specific activity of 10 min−1. UDP-Glc production efficiencies as high as 98% were observed at a flow rate of 0.5 mL/min, at which the substrate residence time over the electrode length down pore entrances was matched to the enzyme activity rate. This flow geometry also prevented an unwanted secondary product hydrolysis reaction, as observed in the test homogeneous solution. Enzyme utilization increased by a factor of 280 compared to test homogeneous conditions due to the continuous flow of fresh substrate over the enzyme. To mimic enzyme complex systems, a two-step sequential reaction using OleD Loki enzyme was performed at membrane pore entrances then exits. After UDP-Glc formation at the entrance electrode, aglycon 4-methylumbelliferone was supplied at the exit face of the reactor, affording overall 80% glycosylation efficiency. The membrane platform showed the ability to be regenerated with purified enzyme as well as directly from expression crude, thus demonstrating a single-step immobilization and purification process.

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Section: Resultsmentioning

confidence: 99%

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

et al. 2014

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“…The cells were then rinsed three times with phosphate‐buffered saline prior to analyses of transfection efficiency and cell viability. In a separate experiment to show the efficient electrophoretic pumping of Lucifer yellow reagent across the membrane from a reservoir, only cells in PBS buffer were flowed through the channel while 1 mg mL −1 Lucifer yellow was placed beneath the electrode/membrane device during the electroporation process.…”

Section: Methodsmentioning

confidence: 99%

Flow‐Through Electroporation of HL‐60 White Blood Cell Suspensions using Nanoporous Membrane Electrodes

Chen

Akenhead

Sun

et al. 2016

Adv Healthcare Materials

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A flow-through electroporation system, based on a novel nanoporous membrane/electrode design, for the delivery of cell wall-impermeant molecules into model leukocytes, HL-60 promyelocytes, was demonstrated. The ability to apply low voltages to cell populations, with nm-scale concentrated electric field in a periodic array, contributes to high cell viability. With applied biases of 1-4V, delivery of target molecules was achieved with 90% viability and up to 65% transfection efficiency. More importantly, the system allowed electrophoretic pumping of molecules from a microscale reservoir across the membrane/electrode system into a microfluidic flow channel for transfection of cells, a design that can reduce reagent amount by eightfold compared to current strategies. The flow-through system, which forces intimate membrane/electrode contact by using a 10μm channel height, can be easily scaled-up by adjusting the microfluidic channel geometry and/or the applied voltage pulse frequency to control cell residence times at the cell membrane/electrode interface. The demonstrated system shows promise in clinical applications where low-cost, high cell viability and high volume transfection methods are needed without the risk of viral vectors. In particular genetic modification of freely mobile white blood cells to either target disease cells or to express desired protein/enzyme biomolecules is an important target platform enabled by this device system.

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“…This functionalized AAO can act as a biological membrane, which is allowing sequential protein binding and release/pumping cycles. Thus, the fabricated membrane realized the application in bio-pharmaceutical field [97].…”

Section: Protein Gatingmentioning

confidence: 99%

The toolbox of porous anodic aluminum oxide–based nanocomposites: from preparation to application

Huang

Mutlu

2020

Colloid Polym Sci

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Anodic aluminum oxide (AAO) templates have been intensively investigated during the past decades and have meanwhile been widely applied through both sacrificial and non-sacrificial pathways. In numerous non-sacrificial applications, the AAO membrane is maintained as part of the obtained composite materials; hence, the template structure and topography determine to a great extent the potential applications. Through-hole isotropic AAO features nanochannels that promote transfer of matter, while anisotropic AAO with barrier layer exhibits nanocavities suitable as independent and homogenous containers. By combining the two kinds of AAO membranes with diverse organic and inorganic materials through physical interactions or chemical bonds, AAO composites are designed and applied in versatile fields such as catalysis, drug release platform, separation membrane, optical appliances, sensors, cell culture, energy, and electronic devices. Therefore, within this review, a perspective on exhilarating prospect for complementary advancement on AAO composites both in preparation and application is provided.

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Dynamic Electrochemical Membranes for Continuous Affinity Protein Separation

Cited by 20 publications

References 29 publications

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

Flow‐Through Electroporation of HL‐60 White Blood Cell Suspensions using Nanoporous Membrane Electrodes

The toolbox of porous anodic aluminum oxide–based nanocomposites: from preparation to application

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