scholarly journals SU-8 Based Waveguide for Optrodes

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 814
Author(s):  
Sara Pimenta ◽  
João F. Ribeiro ◽  
Sandra B. Goncalves ◽  
Marino J. Maciel ◽  
Rosana A. Dias ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Power ◽  
Brain Regions ◽  
Neural Probes ◽  
Tissue Penetration ◽  
In Vivo Experiments ◽  
Small Probe ◽  
Promising Solution ◽  
Neural Probe

Neural probes can be equipped with light for optogenetics applications. Different approaches are used for delivering light to the tissue: an optical fiber coupled to the probe, a µLED or a waveguide integrated on the probe. Small probe dimensions, adequate optical power for photostimulation and good tissue penetration for in-vivo experiments are critical requirements. Thus, integrating a waveguide is a promising solution. This work shows the design and simulation of a SU-8 based waveguide for integration in a neural probe. The waveguide contains 3 apertures, spaced by 0.5 mm, which will allow the photostimulation of different brain regions simultaneously.

scholarly journals Modeling invasion patterns in the glioblastoma battlefield

2021 ◽  
Vol 17 (1) ◽  
pp. e1008632
Author(s):  
Martina Conte ◽  
Sergio Casas-Tintò ◽  
Juan Soler
Keyword(s):  
Evolution Equations ◽  
Dynamical Evolution ◽  
Brain Regions ◽  
Infiltration Capacity ◽  
Invasion Front ◽  
In Vivo Experiments ◽  
Tissue Resistance ◽  
Tissue Porosity ◽  
Non Linear System

Glioblastoma is the most aggressive tumor of the central nervous system, due to its great infiltration capacity. Understanding the mechanisms that regulate the Glioblastoma invasion front is a major challenge with preeminent potential clinical relevances. In the infiltration front, the key features of tumor dynamics relate to biochemical and biomechanical aspects, which result in the extension of cellular protrusions known as tumor microtubes. The coordination of metalloproteases expression, extracellular matrix degradation, and integrin activity emerges as a leading mechanism that facilitates Glioblastoma expansion and infiltration in uncontaminated brain regions. We propose a novel multidisciplinary approach, based on in vivo experiments in Drosophila and mathematical models, that describes the dynamics of active and inactive integrins in relation to matrix metalloprotease concentration and tumor density at the Glioblastoma invasion front. The mathematical model is based on a non-linear system of evolution equations in which the mechanisms leading chemotaxis, haptotaxis, and front dynamics compete with the movement induced by the saturated flux in porous media. This approach is able to capture the relative influences of the involved agents and reproduce the formation of patterns, which drive tumor front evolution. These patterns have the value of providing biomarker information that is related to the direction of the dynamical evolution of the front and based on static measures of proteins in several tumor samples. Furthermore, we consider in our model biomechanical elements, like the tissue porosity, as indicators of the healthy tissue resistance to tumor progression.

scholarly journals In vivo performance of a microelectrode neural probe with integrated drug delivery

2009 ◽  
Vol 27 (1) ◽  
pp. E8 ◽  
Author(s):  
Pratik Rohatgi ◽  
Nicholas B. Langhals ◽  
Daryl R. Kipke ◽  
Parag G. Patil
Keyword(s):  
Drug Delivery ◽  
Treatment Options ◽  
Drug Distribution ◽  
Fused Silica ◽  
Cellular Damage ◽  
Probe Design ◽  
Limiting Factor ◽  
Neural Probes ◽  
Neural Probe

Object The availability of sophisticated neural probes is a key prerequisite in the development of future brain-machine interfaces (BMIs). In this study, the authors developed and validated a neural probe design capable of simultaneous drug delivery and electrophysiology recordings in vivo. Focal drug delivery promises to extend dramatically the recording lives of neural probes, a limiting factor to clinical adoption of BMI technology. Methods To form the multifunctional neural probe, the authors affixed a 16-channel microfabricated silicon electrode array to a fused silica catheter. Three experiments were conducted in rats to characterize the performance of the device. Experiment 1 examined cellular damage from probe insertion and the drug distribution in tissue. Experiment 2 measured the effects of saline infusions delivered through the probe on concurrent electrophysiological measurements. Experiment 3 demonstrated that a physiologically relevant amount of drug can be delivered in a controlled fashion. For these experiments, Hoechst and propidium iodide stains were used to assess insertion trauma and the tissue distribution of the infusate. Artificial CSF (aCSF) and tetrodotoxin (TTX) were injected to determine the efficacy of drug delivery. Results The newly developed multifunctional neural probes were successfully inserted into rat cortex and were able to deliver fluids and drugs that resulted in the expected electrophysiological and histological responses. The damage from insertion of the device into brain tissue was substantially less than the volume of drug dispersion in tissue. Electrophysiological activity, including both individual spikes as well as local field potentials, was successfully recorded with this device during real-time drug delivery. No significant changes were seen in response to delivery of aCSF as a control experiment, whereas delivery of TTX produced the expected result of suppressing all spiking activity in the vicinity of the catheter outlet. Conclusions Multifunctional neural probes such as the ones developed and validated within this study have great potential to help further understand the design space and criteria for the next generation of neural probe technology. By incorporating integrated drug delivery functionality into the probes, new treatment options for neurological disorders and regenerative neural interfaces using localized and feedback-controlled delivery of drugs can be realized in the near future.

Vibration-Assisted Insertion of Flexible Neural Microelectrodes With Bio-Dissolvable Guides for Medical Implantation

2021 ◽  
Author(s):  
Yi Wang ◽  
Yen Yu Ian Shih ◽  
Yuan-shin Lee
Keyword(s):  
Tissue Damage ◽  
Three Dimensional ◽  
Insertion Technique ◽  
Neural Electrode ◽  
In Vivo Experiments ◽  
Neural Probe ◽  
Electrode Insertion ◽  
Neural Microelectrodes

Abstract This paper presents vibration-assisted insertion of flexible neural electrodes with bio-dissolvable guides to deliver accurate microprobe insertion with minimized tissue damage. Invasive flexible neural microprobe is an important new tool for neuromodulation and recording research for medical neurology treatment applications. Flexible neural electrode probes are susceptible to bending and buckling during surgical implantation due to the thin and flexible soft substrates. Inspired by insects in nature, a vibration-assisted insertion technique is developed for flexible neural electrode insertion to deliver accurate microprobe insertion with minimized tissue damage. A three-dimensional combined longitudinal-twisting (L&T) vibration is used to reduce the insertion friction force, and thus reducing soft tissue damage. To reduce the flexible microelectrode buckling during surgical insertion, a bio-dissolvable Polyethylene glycol (PEG) guide is developed for the enhancement of flexible neural probe stiffness. Combining these two methods, the insertion performance of the flexible neural probe is significantly improved. Both the in vitro and the in vivo experiments were conducted to validate the proposed techniques.

scholarly journals Modeling invasion patterns in the glioblastoma battlefield

2020 ◽  
Author(s):  
Martina Conte ◽  
Sergio Casas-Tinto ◽  
Juan Soler
Keyword(s):  
Multidisciplinary Approach ◽  
Brain Regions ◽  
Matrix Degradation ◽  
Infiltration Capacity ◽  
In Vivo Experiments ◽  
The Central Nervous System ◽  
Aggressive Tumor ◽  
Key Features ◽  
Invasion Patterns

Glioblastoma is the most aggressive tumor of the central nervous system, due to its great infiltration capacity. Understanding the mechanisms that regulate the Glioblastoma invasion front is a major challenge with preeminent potential clinical relevance. In the in1ltration front, the key features of its dynamics relate to biochemical and biomechanical aspects, which result in extended cellular protrusions, known as tumor microtubes. The coordination of metalloproteinase expression, extracellular matrix degradation, and integrin activity emerges as leading mechanism that facilitates Glioblastoma expansion and in1ltration in uncontaminated brain regions. We propose a novel multidisciplinary approach, based on in vivo experiments in Drosophila and mathematical models, for the proteins dynamics at the front of Glioblastoma, with a predictive value of the tumor progression.

scholarly journals A novel C-terminal degron identified in bacterial aldehyde decarbonylases using directed evolution

2020 ◽  
Author(s):  
yilan liu ◽  
jinjin chen ◽  
Anna N. Khusnutdinova ◽  
Kevin Correia ◽  
Patrick Diep ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Degradation Mechanism ◽  
Bioinformatic Analysis ◽  
Evolution System ◽  
E Coli ◽  
In Vivo Experiments ◽  
Renewable Feedstock ◽  
The Family ◽  
Promising Solution

Abstract Background: Aldehyde decarbonylase (AD), which converts acyl aldehydes into alkanes, supplies promising solution for producing alkanes from renewable feedstock. However the instability of AD impeded its further application. Therefore, the current study aimed to investigate the degradation mechanism of AD and engineer it towards high stability. Results: Here, we describe the discovery of a degradation tag (degron) in the AD from marine cyanobacterium Prochlorococcus marinus via error-prone PCR based directed evolution system. Bioinformatic analysis revealed this C-terminal degron is common in the family of bacterial ADs and identified a conserved C-terminal motif, RMSAYGLAAA, representing the AD degron (ADcon). Furthermore, we demonstrated that the ATP-dependent proteases ClpAP and Lon are involved in the degradation of AD-tagged proteins in E. coli , thereby limiting alkane production. Deletion or modification of the degron motif increased alkane production in vivo . Conclusions: This work revealed the presence of a novel degron in bacterial ADs responsible for its instability. The in vivo experiments proved eliminating or modifying the degron could stabilize AD, thereby producing higher titers of alkanes.

A multichannel neural probe with embedded microfluidic channels for simultaneous in vivo neural recording and drug delivery

Lab on a Chip ◽  
2015 ◽  
Vol 15 (6) ◽  
pp. 1590-1597 ◽  
Author(s):  
Hyunjoo J. Lee ◽  
Yoojin Son ◽  
Jeongyeon Kim ◽  
C. Justin Lee ◽  
Eui-Sung Yoon ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Neural Recording ◽  
Microfluidic Channels ◽  
Neural Probes ◽  
Neural Probe ◽  
The Brain

Multi-functional neural probes integrated with various stimulation modalities are becoming essential tools in neuroscience to study the brain more effectively.

Microfluidic neural probes: in vivo tools for advancing neuroscience

Lab on a Chip ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1406-1435 ◽  
Author(s):  
Joo Yong Sim ◽  
Matthew P. Haney ◽  
Sung Il Park ◽  
Jordan G. McCall ◽  
Jae-Woong Jeong
Keyword(s):  
Neural Circuits ◽  
Neural Probes ◽  
Nervous Systems ◽  
Recent Advances ◽  
Neural Probe ◽  
Immense Potential

This review discusses recent advances in microfluidic neural probe systems, which hold immense potential asin vivotools for manipulating neural circuits in complex nervous systems.

Stem Cell Cure for Kidney Injury: Therapy to Solve Most Complex Issues in Renal System

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Kidney Injury ◽  
Cell Types ◽  
Tissue Remodelling ◽  
Major Health Problem ◽  
In Vivo Experiments ◽  
Renal Regeneration ◽  
Induced Pluripotent

Renal failure is a major health problem. The mortality rate remain high despite of several therapies. The most complex of the renal issues are solved through stem cells. In this review, different mechanism for cure of chronic kidney injury along with cell engraftment incorporated into renal structures will be analysed. Paracrine activities of embryonic or induced Pluripotent stem cells are explored on the basis of stem cell-induced kidney regeneration. Several experiments have been conducted to advance stem cells to ensure the restoration of renal functions. More vigour and organised protocols for delivering stem cells is a possibility for advancement in treatment of renal disease. Also there is a need for pressing therapies to replicate the tissue remodelling and cellular repair processes suitable for renal organs. Stem cells are the undifferentiated cells that have the ability to multiply into several cell types. In vivo experiments on animal’s stem cells have shown significant improvements in the renal regeneration and functions of organs. Nevertheless more studies show several improvements in the kidney repair due to stem cell regeneration.

In vivo Experiments of Natural Products Protection of Antagonistic Effects of Lead on Iron

2018 ◽  
Vol 68 (12) ◽  
pp. 2747-2751
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Lavinia Stef ◽  
Ioan Pet ◽  
Dorel Dronca ◽  
...  
Keyword(s):  
Aquatic Environment ◽  
Iron Homeostasis ◽  
Iron Concentration ◽  
Antagonistic Effect ◽  
Tissue Samples ◽  
Antagonistic Effects ◽  
In Vivo Experiments ◽  
Living Organisms ◽  
Toxic Potential

Living organisms take nutrients from the environment, and together with them, substances with toxic potential � such as heavy metals. Lead is one common metal pollutant especially in aquatic environment, from where the fish can be intoxicated very easily. Bioavailability, distribution, toxic action, synergistic and antagonistic effects are characteristics which can alter the fish health. Our experimental study followed the effects of lead overload in water on iron distribution, in different tissues sample Carassius gibelio Bloch fish. We performed the experiment in four different fish groups: control C; lead � Pb (administration of lead in water 0.075mg/mL of water, as Pb(NO3)2 x � H2O); lead (the same dose) and 2% of freeze-dry garlic incorporated into fishes� food � Pb+garlic; lead (the same dose) and 2% chlorella incorporated into fishes� food � Pb+chlorella, for 21 consecutive days. The iron concentration was analysed with AAS (Atomic Absorption Spectroscopy) from gills, muscle, skin (and scales), intestine, liver, heart, brain, ovary, testicles, and kidney. The obtained data presented a significantly decrease of iron content in all tested tissue samples that demonstrated, alteration of iron homeostasis, explained by a strong antagonistic effect of lead on iron. Our experiment showed that biologic active principles from garlic and chlorella act like natural protectors, and potentiate the iron deficiency even in the case of lead overload in aquatic environment, for fish.

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