Fabrication and Characterization of Biodegradable Metal Based Microelectrodes for In Vivo Neural Recording

MRS Advances ◽  
2019 ◽  
Vol 4 (46-47) ◽  
pp. 2471-2477
Author(s):  
Chaoxing Zhang ◽  
Teresa H. Wen ◽  
Khaleel A. Razak ◽  
Jiajia Lin ◽  
Edgar Villafana ◽  
...  
Keyword(s):  
Neural Recording ◽  
Neural Signals ◽  
Secondary Surgery ◽  
New Class ◽  
Fabrication And Characterization ◽  
Evoked Activity ◽  
First Time ◽  
The Brain

ABSTRACT:Neural electrodes have been widely used to monitor neural signals and/or deliver electrical stimulation in the brain. Currently, biodegradable and biocompatible materials have been actively investigated to create temporary electrodes that could degrade after serving their functions for neural recording and stimulation from days to months. The new class of biodegradable electrodes eliminate the necessity of secondary surgery for electrode removal. In this study, we created biodegradable, biocompatible, and implantable magnesium (Mg)-based microelectrodes for in vivo neural recording for the first time. Specifically, conductive poly-3,4-ethylenedioxythiophene (PEDOT) was first deposited onto Mg microwire substrates by electrochemical deposition, and a biodegradable insulating polymer was subsequently sprayed onto the surface of electrodes. The tip of electrodes was designed to be conductive for neural recording and stimulation, while the rest of electrodes was insulated with a polymer that is biocompatible with neural tissue. The impedance of Mg-based microelectrodes and their performance during neural recording in the auditory cortex of a mouse were studied. The results first demonstrated the capability of Mg-based microelectrodes for in vivo recording of multi-unit stimulus-evoked activity in the brain.

scholarly journals Development of optically controlled “living electrodes” with long-projecting axon tracts for a synaptic brain-machine interface

2021 ◽  
Vol 7 (4) ◽  
pp. eaay5347
Author(s):  
Dayo O. Adewole ◽  
Laura A. Struzyna ◽  
Justin C. Burrell ◽  
James P. Harris ◽  
Ashley D. Nemes ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Brain Activity ◽  
Optical Recording ◽  
New Class ◽  
Brain Surface ◽  
Machine Interface ◽  
The Brain

For implantable neural interfaces, functional/clinical outcomes are challenged by limitations in specificity and stability of inorganic microelectrodes. A biological intermediary between microelectrical devices and the brain may improve specificity and longevity through (i) natural synaptic integration with deep neural circuitry, (ii) accessibility on the brain surface, and (iii) optogenetic manipulation for targeted, light-based readout/control. Accordingly, we have developed implantable “living electrodes,” living cortical neurons, and axonal tracts protected within soft hydrogel cylinders, for optobiological monitoring/modulation of brain activity. Here, we demonstrate fabrication, rapid axonal outgrowth, reproducible cytoarchitecture, and simultaneous optical stimulation and recording of these tissue engineered constructs in vitro. We also present their transplantation, survival, integration, and optical recording in rat cortex as an in vivo proof of concept for this neural interface paradigm. The creation and characterization of these functional, optically controllable living electrodes are critical steps in developing a new class of optobiological tools for neural interfacing.

Implantable neural interfaces

2018 ◽  
Author(s):  
Stefano Vassanelli
Keyword(s):  
Brain Function ◽  
Large Scale ◽  
Ionic Channels ◽  
Patch Clamp Technique ◽  
Advantages And Disadvantages ◽  
Optogenetic Stimulation ◽  
Physical Interfaces ◽  
The Brain

Establishing direct communication with the brain through physical interfaces is a fundamental strategy to investigate brain function. Starting with the patch-clamp technique in the seventies, neuroscience has moved from detailed characterization of ionic channels to the analysis of single neurons and, more recently, microcircuits in brain neuronal networks. Development of new biohybrid probes with electrodes for recording and stimulating neurons in the living animal is a natural consequence of this trend. The recent introduction of optogenetic stimulation and advanced high-resolution large-scale electrical recording approaches demonstrates this need. Brain implants for real-time neurophysiology are also opening new avenues for neuroprosthetics to restore brain function after injury or in neurological disorders. This chapter provides an overview on existing and emergent neurophysiology technologies with particular focus on those intended to interface neuronal microcircuits in vivo. Chemical, electrical, and optogenetic-based interfaces are presented, with an analysis of advantages and disadvantages of the different technical approaches.

scholarly journals The antimicrobial potential of cannabidiol

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mark A. T. Blaskovich ◽  
Angela M. Kavanagh ◽  
Alysha G. Elliott ◽  
Bing Zhang ◽  
Soumya Ramu ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Modern Medicine ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
New Class ◽  
Clostridioides Difficile ◽  
Excellent Activity ◽  
Induce Resistance ◽  
First Time

AbstractAntimicrobial resistance threatens the viability of modern medicine, which is largely dependent on the successful prevention and treatment of bacterial infections. Unfortunately, there are few new therapeutics in the clinical pipeline, particularly for Gram-negative bacteria. We now present a detailed evaluation of the antimicrobial activity of cannabidiol, the main non-psychoactive component of cannabis. We confirm previous reports of Gram-positive activity and expand the breadth of pathogens tested, including highly resistant Staphylococcus aureus, Streptococcus pneumoniae, and Clostridioides difficile. Our results demonstrate that cannabidiol has excellent activity against biofilms, little propensity to induce resistance, and topical in vivo efficacy. Multiple mode-of-action studies point to membrane disruption as cannabidiol’s primary mechanism. More importantly, we now report for the first time that cannabidiol can selectively kill a subset of Gram-negative bacteria that includes the ‘urgent threat’ pathogen Neisseria gonorrhoeae. Structure-activity relationship studies demonstrate the potential to advance cannabidiol analogs as a much-needed new class of antibiotics.

scholarly journals Synthesis and Characterization of Exopolysaccharide Encapsulated PCL/Gelatin Skin Substitute for Full-Thickness Wound Regeneration

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 854
Author(s):  
Ahmad Hivechi ◽  
Peiman Brouki Milan ◽  
Khashayar Modabberi ◽  
Moein Amoupour ◽  
Kaveh Ebrahimzadeh ◽  
...  
Keyword(s):  
Cell Activity ◽  
Average Diameter ◽  
Skin Substitute ◽  
Full Thickness ◽  
Skin Integrity ◽  
Hematoxylin And Eosin ◽  
First Time ◽  
Full Thickness Wound

Loss of skin integrity can lead to serious problems and even death. In this study, for the first time, the effect of exopolysaccharide (EPS) produced by cold-adapted yeast R. mucilaginosa sp. GUMS16 on a full-thickness wound in rats was evaluated. The GUMS16 strain’s EPS was precipitated by adding cold ethanol and then lyophilized. Afterward, the EPS with polycaprolactone (PCL) and gelatin was fabricated into nanofibers with two single-needle and double-needle procedures. The rats’ full-thickness wounds were treated with nanofibers and Hematoxylin and eosin (H&E) and Masson’s Trichrome staining was done for studying the wound healing in rats. Obtained results from SEM, DLS, FTIR, and TGA showed that EPS has a carbohydrate chemical structure with an average diameter of 40 nm. Cell viability assessments showed that the 2% EPS loaded sample exhibits the highest cell activity. Moreover, in vivo implantation of nanofiber webs on the full-thickness wound on rat models displayed a faster healing rate when EPS was loaded into a nanofiber. These results suggest that the produced EPS can be used for skin tissue engineering applications.

scholarly journals Implantable Optrode Array for Optogenetic Modulation and Electrical Neural Recording

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 725
Author(s):  
Saeyeong Jeon ◽  
Youjin Lee ◽  
Daeho Ryu ◽  
Yoon Kyung Cho ◽  
Yena Lee ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Neural Recording ◽  
Electrophysiological Recording ◽  
Light Emitting ◽  
Technological Advances ◽  
Neuroscience Research ◽  
Cell Type Specific ◽  
Novel Design

During the last decade, optogenetics has become an essential tool for neuroscience research due to its unrivaled feature of cell-type-specific neuromodulation. There have been several technological advances in light delivery devices. Among them, the combination of optogenetics and electrophysiology provides an opportunity for facilitating optogenetic approaches. In this study, a novel design of an optrode array was proposed for realizing optical modulation and electrophysiological recording. A 4 × 4 optrode array and five-channel recording electrodes were assembled as a disposable part, while a reusable part comprised an LED (light-emitting diode) source and a power line. After the characterization of the intensity of the light delivered at the fiber tips, in vivo animal experiment was performed with transgenic mice expressing channelrhodopsin, showing the effectiveness of optical activation and neural recording.

scholarly journals Aptamer-functionalized neural recording electrodes for the direct measurement of cocaine in vivo

2017 ◽  
Vol 5 (13) ◽  
pp. 2445-2458 ◽  
Author(s):  
I. Mitch Taylor ◽  
Zhanhong Du ◽  
Emma T. Bigelow ◽  
James R. Eles ◽  
Anthony R. Horner ◽  
...  
Keyword(s):  
Electrochemical Detection ◽  
Direct Measurement ◽  
Neural Recording ◽  
Dna Aptamer ◽  
Silicon Based ◽  
The Brain ◽  
Recording Electrodes

First everin vivosensor for directly measuring cocaine concentration in the brainviaelectrochemical detection at DNA aptamer functionalized single shank, silicon-based neural recording probes.

scholarly journals Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D

2004 ◽  
Vol 380 (3) ◽  
pp. 749-756 ◽  
Author(s):  
Yong-Xin SUN ◽  
Kazuhito TSUBOI ◽  
Yasuo OKAMOTO ◽  
Takeharu TONAI ◽  
Makoto MURAKAMI ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Brain Homogenate ◽  
Wide Distribution ◽  
Rat Tissues ◽  
Lysophospholipase D ◽  
Pla2 Enzyme ◽  
First Time ◽  
Hydrolysis Of ◽  
The Brain

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA1/PLA2 activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA2 (secretory PLA2), and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA2s were also active with N-palmitoyl-PE, whereas group X sPLA2 and cytosolic PLA2α were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanolamine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA2-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyl-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA2-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.

scholarly journals Identification and characterization of molecular interactions between mortalin/mtHsp70 and HSP60

2005 ◽  
Vol 391 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Renu Wadhwa ◽  
Syuichi Takano ◽  
Kamaljit Kaur ◽  
Satoshi Aida ◽  
Tomoko Yaguchi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Molecular Interactions ◽  
Heat Shock Protein 60 ◽  
Hsp60 Expression ◽  
Mitochondrial Hsp70 ◽  
Shock Proteins ◽  
First Time

Mortalin/mtHsp70 (mitochondrial Hsp70) and HSP60 (heat-shock protein 60) are heat-shock proteins that reside in multiple subcellular compartments, with mitochondria being the predominant one. In the present study, we demonstrate that the two proteins interact both in vivo and in vitro, and that the N-terminal region of mortalin is involved in these interactions. Suppression of HSP60 expression by shRNA (short hairpin RNA) plasmids caused the growth arrest of cancer cells similar to that obtained by suppression of mortalin expression by ribozymes. An overexpression of mortalin, but not of HSP60, extended the in vitro lifespan of normal fibroblasts (TIG-1). Taken together, this study for the first time delineates: (i) molecular interactions of HSP60 with mortalin; (ii) their co- and exclusive localizations in vivo; (iii) their involvement in tumorigenesis; and (iv) their functional distinction in pathways involved in senescence.

Graphite/UPE Nanocomposite: Transport, Thermal, Mechanical and Viscoelastic Properties

2019 ◽  
Vol 23 ◽  
pp. 201-212
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia
Keyword(s):  
Transport Properties ◽  
Unsaturated Polyester ◽  
Homogeneous Distribution ◽  
Thermo Gravimetric ◽  
New Class ◽  
The Matrix ◽  
Novel Method ◽  
Water Transport Properties ◽  
First Time

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.

scholarly journals Fabrication and Characterization of Ta–GelMA–BG Scaffolds by Chemical Crosslinking Processing for Promotion Osteointegration

2021 ◽  
Vol 8 ◽  
Author(s):  
Fujian Zhao ◽  
Xiongfa Ji ◽  
Yang Yan ◽  
Zhen Yang ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Early Stage ◽  
Bone Defects ◽  
Chemical Crosslinking ◽  
Composite Scaffolds ◽  
Load Bearing ◽  
3D Printed ◽  
Fabrication And Characterization ◽  
Cell Adhesion And Proliferation

The repair of bone defects in load-bearing positions still faces great challenges. Tantalum (Ta) has attempted to repair bone defects based on the excellent mechanical properties. However, the osseointegration of Ta needs to be improved due to the lack of osteoinduction. Herein, tantalum–gelatin–methacryloyl–bioactive glass (Ta–GelMA–BG) scaffolds were successfully fabricated by loading BG in 3D-printed Ta scaffolds through a chemical crosslinking method. The results showed that the composite scaffolds have the ability to promote cell adhesion and proliferation. The incorporation of BG resulted in a significant increase in apatite-forming and osteogenesis differentiation abilities. In vivo results indicated that the Ta–GelMA–BG scaffolds significantly enhanced the osteointegration at the early stage after implantation. Overall, the Ta–GelMA–BG scaffolds are a promising platform for the load bearing bone regeneration field.

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