scholarly journals Investigation of the Feasibility of Ventricular Delivery of Resveratrol to the Microelectrode Tissue Interface

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1446
Author(s):  
Youjoung Kim ◽  
Evon S. Ereifej ◽  
William E. Schwartzman ◽  
Seth M. Meade ◽  
Keying Chen ◽  
...  
Keyword(s):  
Brain Research ◽  
Foreign Body Response ◽  
Tissue Response ◽  
Solubility In Water ◽  
Electrophysiological Recordings ◽  
Drug Elution ◽  
Cellular Debris ◽  
Electrode Interface ◽  
The Brain ◽  
Low Solubility

(1) Background: Intracortical microelectrodes (IMEs) are essential to basic brain research and clinical brain–machine interfacing applications. However, the foreign body response to IMEs results in chronic inflammation and an increase in levels of reactive oxygen and nitrogen species (ROS/RNS). The current study builds on our previous work, by testing a new delivery method of a promising antioxidant as a means of extending intracortical microelectrodes performance. While resveratrol has shown efficacy in improving tissue response, chronic delivery has proven difficult because of its low solubility in water and low bioavailability due to extensive first pass metabolism. (2) Methods: Investigation of an intraventricular delivery of resveratrol in rats was performed herein to circumvent bioavailability hurdles of resveratrol delivery to the brain. (3) Results: Intraventricular delivery of resveratrol in rats delivered resveratrol to the electrode interface. However, intraventricular delivery did not have a significant impact on electrophysiological recordings over the six-week study. Histological findings indicated that rats receiving intraventricular delivery of resveratrol had a decrease of oxidative stress, yet other biomarkers of inflammation were found to be not significantly different from control groups. However, investigation of the bioavailability of resveratrol indicated a decrease in resveratrol accumulation in the brain with time coupled with inconsistent drug elution from the cannulas. Further inspection showed that there may be tissue or cellular debris clogging the cannulas, resulting in variable elution, which may have impacted the results of the study. (4) Conclusions: These results indicate that the intraventricular delivery approach described herein needs further optimization, or may not be well suited for this application.

scholarly journals Chronically Implanted Intracranial Electrodes: Tissue Reaction and Electrical Changes

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 430 ◽  
Author(s):  
Andrew Campbell ◽  
Chengyuan Wu
Keyword(s):  
Tissue Reaction ◽  
Tissue Response ◽  
Significant Progress ◽  
Electrode Implantation ◽  
Disease States ◽  
Electrode Interface ◽  
Intracranial Electrodes ◽  
Electrode Systems ◽  
The Brain ◽  
Made In

The brain-electrode interface is arguably one of the most important areas of study in neuroscience today. A stronger foundation in this topic will allow us to probe the architecture of the brain in unprecedented functional detail and augment our ability to intervene in disease states. Over many years, significant progress has been made in this field, but some obstacles have remained elusive—notably preventing glial encapsulation and electrode degradation. In this review, we discuss the tissue response to electrode implantation on acute and chronic timescales, the electrical changes that occur in electrode systems over time, and strategies that are being investigated in order to minimize the tissue response to implantation and maximize functional electrode longevity. We also highlight the current and future clinical applications and relevance of electrode technology.

scholarly journals Formulation Strategies for Enhancing the Bioavailability of Silymarin: The State of the Art

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2155 ◽  
Author(s):  
Alfonso Di Costanzo ◽  
Ruggero Angelico
Keyword(s):  
Herbal Extract ◽  
Limiting Factors ◽  
Solubility In Water ◽  
Stress Effects ◽  
Anti Cancer ◽  
Nanostructured Systems ◽  
Anti Oxidant ◽  
High Doses ◽  
The Brain ◽  
Low Solubility

Silymarin, a mixture of flavonolignan and flavonoid polyphenolic compounds extractable from milk thistle (Silybum marianum) seeds, has anti-oxidant, anti-inflammatory, anti-cancer and anti-viral activities potentially useful in the treatment of several liver disorders, such as chronic liver diseases, cirrhosis and hepatocellular carcinoma. Equally promising are the effects of silymarin in protecting the brain from the inflammatory and oxidative stress effects by which metabolic syndrome contributes to neurodegenerative diseases. However, although clinical trials have proved that silymarin is safe at high doses (>1500 mg/day) in humans, it suffers limiting factors such as low solubility in water (<50 μg/mL), low bioavailability and poor intestinal absorption. To improve its bioavailability and provide a prolonged silymarin release at the site of absorption, the use of nanotechnological strategies appears to be a promising method to potentiate the therapeutic action and promote sustained release of the active herbal extract. The purpose of this study is to review the different nanostructured systems available in literature as delivery strategies to improve the absorption and bioavailability of silymarin.

scholarly journals Advanced Nanotechnologies for Enhancing the Bioavailability of Silymarin: A State of the Art

2019 ◽  
Author(s):  
Alfonso Di Costanzo ◽  
Ruggero Angelico
Keyword(s):  
Herbal Extract ◽  
Limiting Factors ◽  
Solubility In Water ◽  
Stress Effects ◽  
Anti Cancer ◽  
Nanostructured Systems ◽  
Anti Oxidant ◽  
High Doses ◽  
The Brain ◽  
Low Solubility

Silymarin, a mixture of flavonolignan and flavonoid polyphenolic compounds extractable from the milk thistle seed, Silybum marianum, has anti-oxidant, anti-inflammatory, anti-cancer and anti-viral activities potentially useful in the treatment of several liver disorders, such as chronic liver diseases, cirrhosis and hepatocellular carcinoma. Equally promising are the effects of silymarin in protecting the brain from the inflammatory and oxidative stress effects by which metabolic syndrome contributes to neurodegenerative diseases. However, despite clinical trials have proved that silymarin is safe at high doses (&gt;1500 mg/day) in humans, it suffers limiting factors such as low solubility in water (&lt;50 &mu;g/mL), low bioavailability and poor intestinal absorption. To improve its bioavailability and provide a prolonged silymarin release at the site of absorption, the use of nanotechnological strategies appears to be a promising method to potentiate the therapeutic action and promote sustained release of the active herbal extract. The purpose of this study is to review the different nanostructured systems available in literature as delivery strategies to improve the absorption and bioavailability of silymarin.

Neurotoxic and Neuroprotective Role of Exosomes in Parkinson’s Disease

2020 ◽  
Vol 25 (42) ◽  
pp. 4510-4522 ◽  
Author(s):  
Biancamaria Longoni ◽  
Irene Fasciani ◽  
Shivakumar Kolachalam ◽  
Ilaria Pietrantoni ◽  
Francesco Marampon ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Potential Role ◽  
Current Knowledge ◽  
Biological Fluids ◽  
Cell Communication ◽  
Target Cells ◽  
Cellular Debris ◽  
The Brain

: Exosomes are extracellular vesicles produced by eukaryotic cells that are also found in most biological fluids and tissues. While they were initially thought to act as compartments for removal of cellular debris, they are now recognized as important tools for cell-to-cell communication and for the transfer of pathogens between the cells. They have attracted particular interest in neurodegenerative diseases for their potential role in transferring prion-like proteins between neurons, and in Parkinson’s disease (PD), they have been shown to spread oligomers of α-synuclein in the brain accelerating the progression of this pathology. A potential neuroprotective role of exosomes has also been equally proposed in PD as they could limit the toxicity of α-synuclein by clearing them out of the cells. Exosomes have also attracted considerable attention for use as drug vehicles. Being nonimmunogenic in nature, they provide an unprecedented opportunity to enhance the delivery of incorporated drugs to target cells. In this review, we discuss current knowledge about the potential neurotoxic and neuroprotective role of exosomes and their potential application as drug delivery systems in PD.

scholarly journals Prospective study to assess the tissue response to HPC-coated p48 flow diverter stents compared to uncoated devices in the rabbit carotid artery model

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Tim Lenz-Habijan ◽  
Pervinder Bhogal ◽  
Catrin Bannewitz ◽  
Ralf Hannes ◽  
Hermann Monstadt ◽  
...  
Keyword(s):  
Foreign Body ◽  
Flow Diverter ◽  
Foreign Body Response ◽  
Tissue Response ◽  
Acute Setting ◽  
Significant Difference ◽  
And Performance ◽  
Surface Modified ◽  
Common Carotid Arteries

Abstract Background Flow diverters (FDs) are widely used in the treatment of intracranial aneurysms, but the required medication increases the risk of haemorrhagic complications and limits their use in the acute setting. Surface modified FDs may limit the need for dual antiplatelet therapy (DAPT). Hydrophilic polymer coating (HPC) may reduce the need of medication. Methods This explorative study, approved by the local authorities and the local welfare committee, compared stent behaviour and overall tissue response between HPC-coated FDs and uncoated FDs, both implanted into the common carotid arteries of eight New Zealand white rabbits. Endothelialisation, inflammatory response, and performance during implantation were assessed. Angiographic follow-up was performed to observe the patency of the devices after implantation and after 30 days. Histological examinations were performed at 30 days to assess foreign body reaction and endothelialisation. Kruskal-Wallis and Wilcoxon tests were used to compare non-parametric variables. Results Angiography showed that both coated and uncoated FDs performed well during implantation. All devices remained patent during immediate follow-up and after 30 days. Histopathology showed no significant difference in inflammation within the vessel wall between the two cohorts (2.12 ± 0.75 vs. 1.96 ± 0.79, p = 0.7072). Complete endothelialisation of the stent struts was seen with very similar (0.04 ± 0.02 mm vs. 0.04 ± 0.03 mm, p = 0.892) neoendothelial thickness between the two cohorts after 30 days. Conclusion Taking into account the limitation in sample size, non-significant differences between the HPC-coated and uncoated FDs regarding implantation, foreign body response, and endothelialisation were found.

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