1,720,981 research outputs found
Electrochemical layer-by-layer approach to fabricate mechanically stable platinum black microelectrodes using a mussel-inspired polydopamine adhesive
No full textObjective. Platinum black (PtBK) has long been used for microelectrode fabrication owing to its high recording performance of neural signals. The porous structure of PtBK enlarges the surface area and lowers the impedance, which results in background noise reduction. However, the brittleness of PtBK has been a problem in practice. In this work, we report mechanically stable PtBK microelectrodes using a bioinspired adhesive film, polydopamine (pDA), while maintaining the low impedance of PtBK. Approach. The pDA layer was incorporated into the PtBK structure through electrochemical layer-by-layer deposition. Varying the number of layers and the order of materials, multi-layered pDA-PtBK hybrids were fabricated and the electrical properties, both impedance and charge injection limit, were evaluated. Main results. Multilayered pDA-PtBK hybrids had electrical impedances as low as PtBK controls and charge injection limit twice larger than controls. For the 30 min-ultrasonication agitation test, impedance levels rarely changed for some of the pDA-PtBK hybrids indicating that the pDA improved the mechanical property of the PtBK structures. The pDA-PtBK hybrid microelectrodes readily recorded neural signals of cultured hippocampal neurons, where background noise levels and signal-to-noise were 2.43 similar to 3.23 mu V-rms and 28.4 similar to 69.1, respectively. Significance. The developed pDA-PtBK hybrid microelectrodes are expected to be applicable to neural sensors for neural prosthetic studies
Distinct funcional roles of neuronal types in synchronous network bursts of dissociated cultures
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Surface modification of micro electrode array with gold nanorods for photo-thermal stimulation of cultured neuronal networks
No full textModular neuronal networks on planar type microelectrode array using a microchannel device
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Extracellular recordings of local field potentials and spikes from clustered neuronal networks using planar-type microelectrode arrays
No full textAgarose‐Assisted Micro‐Contact Printing for High‐Quality Biomolecular Micro‐Patterns
No full textMicro-contact printing has been developed to print biomolecules, such as cell adhesive molecules, proteins, or DNAs, on a substrate, which can serve as experimental platforms for investigating biological issues and engineering biosensors. Despite the popularity of this method, it has been technically challenging to use a conventional stamp made of a hydrophobic polydimethoxysilane (PDMS) elastomer that often requires surface treatments to facilitate the inking and stamping of biomolecules. In this work, we proposed a new surface modification method for a PDMS stamp using agarose hydrogel and demonstrated the applications to the design of micro-patterned substrates with biomolecules. By using a simple bench-top dip-coating method with a commercial syringe pump to steadily pull out the stamp from boiled agarose solution, we coated an agarose layer on the stamp. It consequentially enhanced the transferability of ink molecules to the target substrate and the uniformity of printed patterns compared to the traditional methods for treating stamp surface such as surfactant coating and temporary oxidation with air plasma. In addition, this microstamping method was also used to produce patterns of proteins with the preservation of bioactivity, which could guide neuronal growth. Thus, we demonstrated the applicability to the interface designs of biochips and biosensors
Generation of Patterned Neuronal Networks on Cell-Repellant Poly(oligo(ethylene glycol) Methacrylate) Films
No full textThe utilization of non-bio-fouling poly(oligo(ethylene glycol) methacrylate) (pOEGMA) films as a background material for the generation of neuronal patterns is reported here. Our previously reported method, which was surface-initiated, atom transfer radical polymerization of OEGMA, and subsequent activation of terminal hydroxyl groups of pOEGMA with disuccinimidyl carbonate, was employed for the generation of activated pOEGMA films on glass. Poly-L-lysine was then microcontact-printed onto the activated polymer films, followed by backfilling with poly(ethylene glycol) moieties. E18 hippocampal neurons were cultured on the chemically patterned substrate, and the resulting neuronal networks were analyzed by phase-contrast microscopy and whole-cell patch clamp method. The results indicated that the pOEGMA films played an important role in the generation of good-quality neuronal patterns for up to two weeks without any negative effects to neurons.We thank Alexander Shalek of the Department of Chemistry and Chemical
Biology of Harvard University for the patch clamp analysis. I.S.C. was
grateful to the LG Yonam Foundation and K.K. to the BK21 program
for financial support. This research was also supported by the National
Research Foundation of Korea funded by the Ministry of Education, Science
and Technology (2009-0083525 and 2009-0080081), Chung Moon
Soul Center for Bio-information and Electronics in KAIST, and Industrial
Source Technology Development Programs by Ministry of Knowledge
Economy in Korea.
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