Unfolding collapsed polyelectrolytes in alternating-current electric fields

Hsiao, Pai‐Yi; Wei, Yu-Fu

doi:10.1039/c0sm00848f

Cited by 24 publications

(37 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This rate exceeds the critical shear rate required to dehybridize dsDNAs (about 300 s À1 .) 113,115 Similar order of magnitude electrophoretic 116,117,168 and mechanical AFM 169 dehybridization forces have been reported. Hence, it is necessary to lengthen the translocation time of miRNA beyond 10 ms for hybridization in a small conical nanopore.…”

Section: -16mentioning

confidence: 77%

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

et al. 2016

Self Cite

View full text Add to dashboard Cite

Nucleic acid biomarkers have enormous potential in non-invasive diagnostics and disease management. In medical research and in the near future in the clinics, there is a great demand for accurate miRNA, mRNA, and ctDNA identification and profiling. They may lead to screening of early stage cancer that is not detectable by tissue biopsy or imaging. Moreover, because their cost is low and they are non-invasive, they can become a regular screening test during annual checkups or allow a dynamic treatment program that adjusts its drug and dosage frequently. We briefly review a few existing viral and endogenous RNA assays that have been approved by the Federal Drug Administration. These tests are based on the main nucleic acid detection technologies, namely, quantitative reverse transcription polymerase chain reaction (PCR), microarrays, and next-generation sequencing. Several of the challenges that these three technologies still face regarding the quantitative measurement of a panel of nucleic acids are outlined. Finally, we review a cluster of microfluidic technologies from our group with potential for point-of-care nucleic acid quantification without nucleic acid amplification, designed to overcome specific limitations of current technologies. We suggest that integration of these technologies in a modular design can offer a low-cost, robust, and yet sensitive/selective platform for a variety of precision medicine applications.

show abstract

Section: -16mentioning

confidence: 77%

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Alternative mechanisms could act intracellularly, such as through field-induced actin polarization [49, 50], and are an intriguing avenue for future research.…”

Section: Resultsmentioning

confidence: 99%

Electrokinetic confinement of axonal growth for dynamically configurable neural networks

et al. 2013

View full text Add to dashboard Cite

Axons in the developing nervous system are directed via guidance cues, whose expression varies both spatially and temporally, to create functional neural circuits. Existing methods to create patterns of neural connectivity in vitro use only static geometries, and are unable to dynamically alter the guidance cues imparted on the cells. We introduce the use of AC electrokinetics to dynamically control axonal growth in cultured rat hippocampal neurons. We find that the application of modest voltages at frequencies on the order of 105 Hz can cause developing axons to be stopped adjacent to the electrodes while axons away from the electric fields exhibit uninhibited growth. By switching electrodes on or off, we can reversibly inhibit or permit axon passage across the electrodes. Our models suggest that dielectrophoresis is the causative AC electrokinetic effect. We make use of our dynamic control over axon elongation to create an axon-diode via an axon-lock system that consists of a pair of electrode `gates' that either permit or prevent axons from passing through. Finally, we developed a neural circuit consisting of three populations of neurons, separated by three axon-locks to demonstrate the assembly of a functional, engineered neural network. Action potential recordings demonstrate that the AC electrokinetic effect does not harm axons, and Ca2+ imaging demonstrated the unidirectional nature of the synaptic connections. AC electrokinetic confinement of axonal growth has potential for creating configurable, directional neural networks.

show abstract

“…Compared to uncharged polymers with mainly permanent dipole moment and/or comparatively weak induced moment, charged polymers can generate extra stretch torque because ion transport can significantly influence the electric field distribution. [12][13][14][15][16][17][18] For instance, electric field effects on polyelectrolytes have been largely utilized to separate DNA by electrophoresis. As one type of charged polymers, polyelectrolytes contain ionizable groups that can dissociate in polar solvents to create charged polymer chains as well as small mobile counterions that can escape into the bulk solution.…”

Section: Introductionmentioning

confidence: 99%

“…5,[7][8][9][10][11] The influence of uniform electric field on the dynamics and conformations of polyelectrolyte chains was also studied in a series of works. [12][13][14][15][16][17][18] For instance, electric field effects on polyelectrolytes have been largely utilized to separate DNA by electrophoresis. 18 Recently, Netz systematically investigated the stretch behavior of a single charged polymer in electric field using Brownian dynamics simulations and scaling arguments 12 and predicted that the single charged polymer chain will be unfolded with specific stretch along the field direction when the applied electric field slowly increases.…”

Section: Introductionmentioning

confidence: 99%

Electric field‐induced stretch of pyrene‐labeled diblock weak polyelectrolyte in dilute solution monitored by steady‐state fluorescence

Tan¹,

Shu²,

Yi³

et al. 2012

J of Applied Polymer Sci

View full text Add to dashboard Cite

Pyrene-labeled diblock weak polyelectrolyte of poly (2-hydroxyethyl methacrylate)-b-poly (2-(dimethylamino) ethyl methacrylate) (Py-PHEMA-b-PDMAEMA) was successfully synthesized by atom transfer radical polymerization. The behavior of electric field induced diblock polyelectrolyte chain stretch in dilute solution was investigated by steady-state fluorescence spectroscopy. The effect of diblock polyelectrolyte concentration, pH value, salt concentration, and solvent viscosity on electric field-induced stretch was thoroughly investigated by the ratio (I E /I M ) of excimer-to-monomer emission intensities obtained from the steady-state fluorescence spectroscopy. The results indicate that the weak diblock polyelectrolyte coil undergoes a stretching process in an external electric field, resulting in the electric field-induced stretch. An increasing polyelectrolyte concentration is advantageous to electric field-induced stretch. The degree of electric field-induced stretch is increased with the decrease of pH value by adding acid. In the presence of NaCl, the degree of electric field-induced stretch is increased with an increasing of salt concentration. However, an increase of solvent viscosity is disadvantageous to electric field-induced stretch.

show abstract

Unfolding collapsed polyelectrolytes in alternating-current electric fields

Cited by 24 publications

References 47 publications

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

Electrokinetic confinement of axonal growth for dynamically configurable neural networks

Electric field‐induced stretch of pyrene‐labeled diblock weak polyelectrolyte in dilute solution monitored by steady‐state fluorescence

Contact Info

Product

Resources

About