Enhanced mixing in polyacrylamide gels containing embedded silica nanoparticles as internal electroosmotic pumps

Matos, Marvi A.; White, Lee R.; Tilton, Robert D.

doi:10.1016/j.colsurfb.2007.08.013

Cited by 17 publications

(17 citation statements)

References 24 publications

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“…hNSCs were placed on the interdigitated electrodes (Figure 1a), and then AC electric fields ( Vpeak = 100 mV) and/or direct current (DC) electric fields (15 mV) were applied while hNSCs were maintained under proliferation or differentiation conditions. Compared to hNSCs without electric fields as a control, hNSCs were nearly unaffected by AC, while DC induced cell death subtantially under both proliferation and differentiation conditions (Figures 1b and 1c), which is consistent with previously reported results19202122. However, when DC was applied with AC (AC/DC), the cells appeared to proliferate or differentiate well (Figures 1b and 1c); moreover, some neurite extensions from differentiated cells seemed to align along the direction of the DC (Figure 1c).…”

Section: Resultssupporting

confidence: 92%

Real-Time Discrimination between Proliferation and Neuronal and Astroglial Differentiation of Human Neural Stem Cells

Lee

Kim

Han

et al. 2014

Sci Rep

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Neural stem cells (NSCs) are characterized by a capacity for self-renewal, differentiation into multiple neural lineages, all of which are considered to be promising components for neural regeneration. However, for cell-replacement therapies, it is essential to monitor the process of in vitro NSC differentiation and identify differentiated cell phenotypes. We report a real-time and label-free method that uses a capacitance sensor array to monitor the differentiation of human fetal brain-derived NSCs (hNSCs) and to identify the fates of differentiated cells. When hNSCs were placed under proliferation or differentiation conditions in five media, proliferating and differentiating hNSCs exhibited different frequency and time dependences of capacitance, indicating that the proliferation and differentiation status of hNSCs may be discriminated in real-time using our capacitance sensor. In addition, comparison between real-time capacitance and time-lapse optical images revealed that neuronal and astroglial differentiation of hNSCs may be identified in real-time without cell labeling.

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Section: Resultssupporting

confidence: 92%

Real-Time Discrimination between Proliferation and Neuronal and Astroglial Differentiation of Human Neural Stem Cells

Lee

Kim

Han

et al. 2014

Sci Rep

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“…As mentioned above, key assumptions include that the fluid is Newtonian and the flow is incompressible; the system is under steadystate; and the hydrodynamic flow regime is pressure driven within two stationary walls i.e., Poiseuille flow. Since the cross-section of the microvoid is varying axially, the pressure difference is calculated as a function of axial direction, ∆P(x), for a given constant volumetric flow rate and is given as: (4) where Q is the volumetric flow rate, L is microvoid length, H is the height, h(x) is the equation of the line representing the walls of the microvoid.…”

Section: Governing Equationsmentioning

confidence: 99%

Assessing Performance of Irregular Microvoids in Electrophoresis Separations

Simhadri

Stretz

Oyanader

et al. 2015

Ind. Eng. Chem. Res.

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Within the last decade, novel gel materials with a modified internal morphology have been synthesized and are available for a wide range of applications including drug delivery, separation of biomolecules with relevance in clinical diagnostics, electrokinetic pumping, and sensors 1-3 . One way to achieve this internal modification is to embed nanoparticles into the polymer matrix, so that when an electrical field is applied to the system, the presence of these particles can change the biomacromolecule transport through the gel, possibly altering the separation 4 . As a result, gaining a very deep understanding of the role that these nanoparticles can have on the separation efficiency in terms of electrophoresis techniques becomes very important. To the best of our knowledge, this contribution is the first effort that examines the role of morphology (in the form of a axially-diverging microdomain) on the prediction of optimal separation times for two protein models when they are subjected to electrophoresis. The research conducted predicts that the optimal separation time of a short, straight pore yields the best resolution in this type of electrophoretic separation.

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“…11 Introducing silica nanoparticles into polyacrylamide hydrogels 8b creates an electroosmotic pumping mechanism to increase solute flux into and out of polyacrylamide hydrogels. 12 These nanoparticle-doped hydrogels have been assessed theoretically to understand how the added nanoparticles alter solute flux in an electric field. 13 Thus, the development and fine control over electrokinetic transport in polymeric gels, and in channels with walls of multilayered polyelectrolytes, have been of long-standing interest and practical importance.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of a Hydrogel with Controllable Electroosmosis: A Potential Brain Tissue Surrogate for Electrokinetic Transport

et al. 2011

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Electroosmosis is the bulk fluid flow initiated by application of an electric field to an electrolyte solution in contact with immobile objects with a non-zero ζ-potential such as the surface of a porous medium. Electroosmosis may be used to assist analytical separations. Several gel-based systems with varying electroosmotic mobilities have been made in this context. A method was recently developed to determine the ζ-potential of organotypic hippocampal slice cultures (OHSC) as a representative model for normal brain tissue. The ζ-potential of the tissue is significant. However, determining the role of the ζ-potential in solute transport in tissue in an electric field is difficult because the tissue's ζ-potential cannot be altered. We hypothesized that mass transport properties, namely the ζ-potential and tortuosity, could be modulated by controlling the composition of a set of hydrogels. Thus, poly(acrylamide-co-acrylic acid) gels were prepared with three compositions (by monomer weight percent): acrylamide/acrylic acid 100/0, 90/10, and 75/25. The ζ-potentials of these gels at pH 7.4 are distinctly different, and in fact vary approximately linearly with the weight percent of acrylic acid. We discovered that the 25% acrylic acid gel is a respectable model for brain tissue, as its ζ-potential is comparable to the OHSC. This series of gels permits the experimental determination of the importance of electrokinetic properties in a particular experiment or protocol. Additionally, tortuosities were measured electrokinetically and by evaluating diffusion coefficients. Hydrogels with well-defined ζ-potential and tortuosity may find utility in biomaterials, analytical separations, and as a surrogate model for OHSC and living biological tissues.

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Enhanced mixing in polyacrylamide gels containing embedded silica nanoparticles as internal electroosmotic pumps

Cited by 17 publications

References 24 publications

Real-Time Discrimination between Proliferation and Neuronal and Astroglial Differentiation of Human Neural Stem Cells

Real-Time Discrimination between Proliferation and Neuronal and Astroglial Differentiation of Human Neural Stem Cells

Assessing Performance of Irregular Microvoids in Electrophoresis Separations

Synthesis and Characterization of a Hydrogel with Controllable Electroosmosis: A Potential Brain Tissue Surrogate for Electrokinetic Transport

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