Browsing by Author "Chu, Chao-Yi"

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Conductive nanogel-interfaced neural microelectrode arrays with electrically controlled in-situ delivery of manganese ions enabling high-resolution MEMRI for synchronous neural tracing with deep brain stimulation
(2017-04)
Huang, Wei-Chen
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Lo, Yu-Chih
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Chu, Chao-Yi
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Lai, Hsin-Yi
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Chen, You-Yin
Chronic brain stimulation has become a promising physical therapy with increased efficacy and efficiency in the treatment of neurodegenerative diseases. The application of deep brain electrical stimulation (DBS) combined with manganese-enhanced magnetic resonance imaging (MEMRI) provides an unbiased representation of the functional anatomy, which shows the communication between areas of the brain responding to the therapy. However, it is challenging for the current system to provide a real-time high-resolution image because the incorporated MnCl2 solution through microinjection usually results in image blurring or toxicity due to the uncontrollable diffusion of Mn2+. In this study, we developed a new type of conductive nanogel-based neural interface composed of amphiphilic chitosan-modified poly(3,4 -ethylenedioxythiophene) (PMSDT) that can exhibit biomimic structural/mechanical properties and ionic/electrical conductivity comparable to that of Au. More importantly, the PMSDT enables metal-ligand bonding with Mn2+ ions, so that the system can release Mn2+ ions rather than MnCl2 solution directly and precisely controlled by electrical stimulation (ES) to achieve real-time high resolution MEMRI. With the integration of PMSDT nanogel-based coating in polyimide-based micro electrode arrays, the post-implantation DBS enables frequency-dependent MR imaging in vivo, as well as small focal imaging in response to channel site-specific stimulation on the implant. The MR imaging of the implanted brain treated with 5-min electrical stimulation showed a thalamocortical neuronal pathway after 36 h, confirming the effective activation of a downstream neuronal circuit following DBS. By eliminating the susceptibility to artifact and toxicity, this system, in combination with a MR-compatible implant and a bio-compliant neural interface, provides a harmless and synchronic functional anatomy for DBS. The study demonstrates a model of MEMRI-functionalized DBS based on functional neural interface engineering and controllable delivery technology, which can be utilized in more detailed exploration of the functional anatomy in the treatment of neurodegenerative diseases. (C) 2017 Elsevier Ltd. All rights reserved.
Highly sensitive/selective 3D nanostructured immunoparticle-based interface on a multichannel sensor array for detecting amyloid-beta in Alzheimer's disease
(2018-01-01)
Liu, Ta-Chung
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Lee, Yi-Chao
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Ko, Chiung-Yuan
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Liu, Ren-Shyan
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Ke, Chien-Chih
Accumulation of beta-amyloid (A beta) peptides is highly associated with Alzheimer's disease (AD) progression in prevailing studies. The successful development of an ultrasensitive detection assay for A beta is a challenging task, especially from blood-based samples. Methods: We have developed a one-step electrophoresis/electropolymerization strategy for preparing a CSIP hierarchical immunoelectrochemical interface that is easily integrated into a PoCT device. The interface includes conductive silk fibroin-based immunoparticles (CSIPs) via electropolymerized Poly(3,4-ethylenedioxythiophene) (PEDOT) bridging to enable on-site electrochemical detection of serum amyloid-beta(42) (A beta(42)) and -beta(40) (A beta(40)) peptides from an AD blood test. In addition, micro-positron emission tomography (microPET) neuroimaging and behavioral tests were simultaneously performed. Results: This nanostructured conductive interface favors penetration of water-soluble biomolecules and catalyzes a redox reaction, providing limits of detection (LOD) of 6.63 pg/mL for A beta(40) and 3.74 pg/mL for A beta(42). Our proof-of-concept study confirms that the multi-sensing electrochemical immunosensor array (MEIA) platform enables simultaneous measurement of serum A beta(42) and A beta(40) peptide levels and is more informative in early stage AD animals than amyloid-labeling A beta plaque PET imaging and behavioral tests. Conclusion: We believe this study greatly expands the applications of silk fibroin-based materials, is an important contribution to the advancement of biomaterials, and would also be valuable in the design of new types of multichannel electrochemical immunosensor arrays for the detection of other diseases.
Implantable Graphene-based Neural Electrode Interfaces for Electrophysiology and Neurochemistry in In Vivo Hyperacute Stroke Model
(2016-01-13)
Liu, Ta-Chung
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Chuang, Min-Chieh
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Chu, Chao-Yi
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Huang, Wei-Chen
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Lai, Hsin-Yi
Implantable microelectrode arrays have attracted considerable interest due to their high temporal and spatial resolution recording of neuronal activity in tissues. We herein presented an implantable multichannel neural probe with multiple real-time monitoring of neural-chemical and neural-electrical signals by a nonenzymatic neural-chemical interface, which was designed by creating the newly developed reduced graphene oxide-gold oxide (rGO/Au2O3) nanocomposite electrode. The modified electrode on the neural probe was prepared by a facile one-step cyclic voltammetry (CV) electrochemical method with simultaneous occurrence of gold oxidation and GOs reduction to induce the intimate attachment by electrostatic interaction using chloride ions (Cl-). The rGO/Au2O3-modified electrode at a low deposition scan rate of 10 mVs(-1) displayed significantly improved electrocatalytic activity due to large active areas and well-dispersive attached rGO sheets. The in vitro amperometric response to H2O2 demonstrated a fast response of less than 5 s and a very low detection limit of 0.63 mu M. In in vivo hyperacute stroke model, the concentration of H2O2 was measured as 100.48 +/- 4.52 mu M for rGO/Au2O3 electrode within 1 h photothrombotic stroke, which was much higher than that (71.92 mu M +/- 2.52 mu M) for noncoated electrode via in vitro calibration. Simultaneously, the somatosensory-evoked potentials (SSEPs) test provided reliable and precise validation for detecting functional changes of neuronal activities. This newly developed implantable probe with localized rGO/Au2O3 nanocomposite electrode can serve as a rapid and reliable sensing platform for practical H2O2 detection in the brain or for other neural-chemical molecules in vivo.
Neurotensin-Conjugated Reduced Graphene Oxide with Multi-Stage Near-Infrared-Triggered Synergic Targeted Neuron Gene Transfection In Vitro and In Vivo for Neurodegenerative Disease Therapy
(2016-12)
Hsieh, Tsung-Ying
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Huang, Wei-Chen
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Kang, Yi-Da
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Chu, Chao-Yi
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Liao, Wen-Lin
Delivery efficiency with gene transfection is a pivotal point in achieving maximized therapeutic efficacy and has been an important challenge with central nervous system (CNS) diseases. In this study, neurotensin (NT, a neuro-specific peptide)-conjugated polyethylenimine (PEI)-modified reduced graphene oxide (rGO) nanoparticles with precisely controlled two-stage near-infrared (NIR)-laser photothermal treatment to enhance the ability to target neurons and achieve high gene transfection in neurons. First-stage NIR laser irradiation on the cells with nanoparticles attached on the surface can increase the permeability of the cell membrane, resulting in an apparent increase in cellular uptake compared to untreated cells. In addition, second-stage NIR laser irradiation on the cells with nanoparticles inside can further induce endo/lysosomal cavitation, which not only helps nanoparticles escape from endo/lysosomes but also prevents plasmid DNA (pDNA) from being digested by DNase I. At least double pDNA amount can be released from rGO-PEI-NT/pDNA under NIR laser trigger release compared to natural release. Moreover, in vitro differentiated PC-12 cell and in vivo mice (C57BL/6) brain transfection experiments have demonstrated the highest transfection efficiency occurring when NT modification is combined with external multi-stage stimuli-responsive NIR laser treatment. The combination of neuro-specific targeting peptide and external NIR-laser-triggered aid provides a nanoplatform for gene therapy in CNS diseases.
Newly reduced graphene oxide/gold oxide neural-chemical interface on multi-channel neural probes to enhance the electrochemical properties for biosensors
(2016-01-01)
Liu, Ta-Chung
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Chu, Chao-Yi
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Chen, You-Yin
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Chen, San-Yuan
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材料科學與工程學系
In this study, a facile one-step Cyclic Voltammetry (CV) electrophoresis was proposed for designing a reduced graphene oxide/gold oxide (rGO/AuOx) modified electrode by using chloride ions (Cl-) with the simultaneous occurrence of gold oxidation and GO reduction to induce the intimate attachment of negatively charged rGO sheets on the positively charged Au+/Au3+ clusters by electrostatic interaction. The surface microstructure and the oxygen functional groups of rGO/AuOx can be tuned by controlling the dissolution rate of gold via the deposition scan rate. At a low deposition scan rate, the rGO/AuOx electrode with well-dispersive rGO sheets and large active sites can induce rapid electron transfer to promote H2O2 detection. The amperometric response results displayed a relative fast response of less than 5 s with a low detection limit of 0.63 mu M (S/N = 3). Also, the rGO/AuOx neural-chemical interface can be modified at the multi-channels on neural probe and they exhibited excellent sensing performance to H2O2. The results demonstrated that the rGO/AuOx modified electrode integrated with a neural probe using this one-step electrochemical deposition can provide a faster response and higher sensitivity by optimizing and controlling the surface microstructures of rGO/AuOx, which would serve as a platform for medical application such as biosensors for multi-sensing.