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

Abstract

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.

Light-Induced Self-Assembled Polydiacetylene/Carbon Dot Functional “Honeycomb”

“…Functional supramolecular assemblies have attracted broad interest due to the versatility of structural properties and potential applications. Micro/nanopatterned assemblies in particular have been employed as platforms for particle sensing, , membrane separation/filtration, , catalysis, drug encapsulation/delivery, , and tissue engineering. , Compared to soft-lithography or the use of colloidal or emulsion templates, supramolecular self-assembly using simple building blocks offers readily implemented approach for the fabrication of ordered macro-porous structures. , The choice of molecular constituents and available synthetic routes furnishes tunability of film architecture, pore size and organization, and surface properties. , In addition, functional group intercalated polymers can be used to control the hydrophobicity of porous scaffolds or facilitate specific interactions with target molecules. , …”

“…12,13 In addition, functional group intercalated polymers can be used to control the hydrophobicity of porous scaffolds or facilitate specific interactions with target molecules. 14,15 Polydiacetylenes (PDAs) are a class of unique chromatic conjugated polymers formed by the topochemical ultraviolet (UV) light induced polymerization of diacetylene (DA). 16−18 Diacetylene units can be particularly incorporated within varied linear or cyclic molecular scaffolds, giving rise to stable self-assembled nano-and microstructures.…”

Porous organic polymers for drug delivery: hierarchical pore structures, variable morphologies, and biological properties

“…[44][45][46] Light, gas, and ultrasound are recognized as clean, green, and harmless stimuli that can be used remotely without direct physical or chemical contact and extrusion. 47 Furthermore, enzymes and biomolecules are also inevitable biological stimuli; 48 for example, folic acid (FA) has been used as a targeted delivery ligand and therapeutic agent because of its high affinity for folate receptors. 49,50 These features of POPs provide some possibilities for special functions in sensors, packaging, absorption, and separation.…”

Selective Immobilization of His-Tagged Enzyme on Ni-Chelated Ion Exchange Resin and Its Application in Protein Purification

“…Ideal immobilized enzyme carrier materials usually have the following characteristics: (1) low price, easy to obtain; (2) good chemical and mechanical stability; (3) large specific surface area and good pore structure; (4) good affinity for enzymes; (5) surfaces that are easily functionalized and attached to by enzymes; (6) convenient recycling and reuse; (7) environmentally friendly [ 10 ]. Various materials have been used as matrix, carriers, or supports for enzyme immobilization, such as biopolymers [ 11 ], synthetic polymers [ 12 , 13 ], organic–inorganic composites [ 14 ], porous ceramics [ 15 ], and nanoparticles [ 16 ].…”