Role of Nanocomposite Hydrogel Morphology in the Electrophoretic Separation of Biomolecules: A Review

Abstract

Hydrogels are widely used to produce biomolecular separations in electrophoretic applications, where gel morphology and charge effects combine to produce the separation. Nanocomposite gels are poised to revolutionize this field in both improved handling characteristics and improved separations. Gel morphology and charge effects have traditionally been manipulated by varying the copolymer composition, but recent reports show that novel morphological changes can also be induced in the gel using templating methods and nanoparticle addition. To aid realization of the potential for novel electrically driven separations arising from such novel morphologies, we review here advances in materials development alongside a review of the directions in biomolecule/hydrogel electrophoretic transport modeling. Models for polyelectrolyte transport that are potentially useful for understanding novel behaviors caused by gel morphology are analyzed first. With the perspective of theoretical guidance, we then survey nanocomposite hydrogel morphologies keyed by the nanoparticle and matrix. Finally, we survey as well reports of dramatic improvements in the mechanical properties that may be the key to the early adoption of these new materials in biomolecular separation applications. For modeling, we have identified the different scales involved in biomolecular transport in these materials and provided a taxonomy of transport models that emphasize the role of gel morphology in determining both polyelectrolyte mobility and diffusion. Three aspects for future work unique to nanocomposite gel materials are described: (a) descriptions of the distribution of nanoparticles within the gels; (b) descriptions of the motion of the buffer solution that may include electroosmotic effects for nanoparticles with surface charges; (c) descriptions of the motion of the polyelectrolyte molecule inside the new gel material for a given application. These aspects will help to uncover further quantitative details about the ability of these gels to be tunable for differential mass transport of a given type of molecule. Standard gels, currently, lack a broad flexibility to increase the separation of biomolecules and, in general, are not tunable.

Structured Macroporous Hydrogels: Progress, Challenges, and Opportunities

“…[25][26][27][28] Even more interesting properties for some applications could be achieved if this introduction of larger micropores or macropores was combined with the effective alignment of those pores, [29] facilitating added benefits such as directional cell growth, [30] extremely low pressure drops, [4] and faster diffusion. [31] The shape and microarchitecture of the pores can also be leveraged to influence phenomena such as oxygen and www.advancedsciencenews.com www.advhealthmat.de nutrient transport as well as cell migration and proliferation within the hydrogel.…”

“…[1] The soft mechanics, capacity for rapid internal diffusion of water-soluble components, tunable interfacial affinity for target molecules, and capacity for environmentally responsive physicochemical changes, all controllable based on the crosslink density and chemistry of the hydrogel, make hydrogels highly relevant for biomedical, [1][2][3] bioseparations, [4][5][6] environmental, [7][8][9] and personal care applications, [10,11] among others. Biomedical applications including tissue engineering, [12] drug delivery, [13] and cell encapsulation [14] can particularly benefit from the properties of hydrogels, as hydrogels can effectively mimic the interfacial, chemical, mechanical, and biological functions of native extracellular matrix (ECM).…”

Transport in droplet-hydrogel composites: response to external stimuli

“…In parallel, the transport of ions through electrically charged porous media and hydrogels has been an important and well-known multiscale problem in geosciences and porous materials modeling [28,29,50,51]. Similarly, in the last decade, the electrical conductivity of hydrogel-based composites has come into focus both theoretically and experimentally [52]. However, in spite of experimental studies on developing droplethydrogel composites, there is no theoretical work on the electrical conductivity of these hydrogel-based composites.…”

Choosing the Optimal Gel Morphology in Electrophoresis Separation by a Differential Evolution Approach (Dea)

“…Gel morphology and charge effects have traditionally been manipulated by varying the copolymer composition (Stellawagen, 2009;Stellawagen and Stellawagen, 2009;Simhadri et al, 2010), but recent reports show that novel morphological changes can also lead to unique separations. Morphological changes can be induced in the gel using templating methods (Rill et al, 1996) and nanoparticle addition (Schexnailder and Schmidt, 2009 was played by geometrical parameters in the study of transport properties relevant for the separation of biomacromolecules.…”