Biocompatibility of polyimide-based neural interfaces for chronic implant applications

2007 ◽  
Vol 1 (1) ◽  
Author(s):  
Watkins S. ◽  
D. Gandhi ◽  
P.J. Rousche
Keyword(s):  
Scar Tissue ◽  
Polyglycolic Acid ◽  
Foreign Body Response ◽  
Polymer Materials ◽  
Neural Interfaces ◽  
Surrounding Tissue ◽  
Design Strategies ◽  
Neural Implants ◽  
Technological Advances ◽  
The Central Nervous System

Neural interfaces provide functional re-establishment of the central nervous system, as well as accessibility to monitor physiological responses at a cellular and molecular level. An ideal device is electrically, mechanically, and biologically compatible in long-term applications. Reducing the foreign body response and scar tissue formation caused by the surrounding tissue of the implant makes the device most biocompatible, while not hindering the electrical interface of the device. Technological advances in polymer materials are leading to improved designs of neural implants with the utilization of flexible polyimide, which decreases the relative micromotion strain. However, the flexibility of polyimide causes the device to buckle during insertion; therefore a biodegradable polymer, polyglycolic acid (PGA), is added to the polyimide device in order to temporarily enhance the structural rigidity. In this study we detail the successful biocompatibility demonstrated with both uncoated and PGA coated polyimide devices to provide new design strategies for neural implants used in chronic applications.

scholarly journals Inflammatory Foreign Body Response Induced by Neuro-Implants in Rat Cortices Depleted of Resident Microglia by a CSF1R Inhibitor and Its Implications

2021 ◽  
Vol 15 ◽  
Author(s):  
Aviv Sharon ◽  
Maciej M. Jankowski ◽  
Nava Shmoel ◽  
Hadas Erez ◽  
Micha E. Spira
Keyword(s):  
Foreign Body ◽  
Brain Research ◽  
Field Potential ◽  
Scar Tissue ◽  
Protective Role ◽  
Foreign Body Response ◽  
Surrounding Tissue ◽  
Time Space ◽  
Inflammatory Processes ◽  
Body Response

Inflammatory encapsulation of implanted cortical-neuro-probes [the foreign body response (FBR)] severely limits their use in basic brain research and in clinical applications. A better understanding of the inflammatory FBR is needed to effectively mitigate these critical limitations. Combining the use of the brain permeant colony stimulating factor 1 receptor inhibitor PLX5622 and a perforated polyimide-based multielectrode array platform (PPMP) that can be sectioned along with the surrounding tissue, we examined the contribution of microglia to the formation of inflammatory FBR. To that end, we imaged the inflammatory processes induced by PPMP implantations after eliminating 89–94% of the cortical microglia by PLX5622 treatment. The observations showed that: (I) inflammatory encapsulation of implanted PPMPs proceeds by astrocytes in microglia-free cortices. The activated astrocytes adhered to the PPMP’s surfaces. This suggests that the roles of microglia in the FBR might be redundant. (II) PPMP implantation into control or continuously PLX5622-treated rats triggered a localized surge of microglia mitosis. The daughter cells that formed a “cloud” of short-lived (T1/2 ≤ 14 days) microglia around and in contact with the implant surfaces were PLX5622 insensitive. (III) Neuron degeneration by PPMP implantation and the ensuing recovery in time, space, and density progressed in a similar manner in the cortices following 89–94% depletion of microglia. This implies that microglia do not serve a protective role with respect to the neurons. (IV) Although the overall cell composition and dimensions of the encapsulating scar in PLX5622-treated rats differed from the controls, the recorded field potential (FP) qualities and yield were undistinguishable. This is accounted for by assuming that the FP amplitudes in the control and PLX5622-treated rats were related to the seal resistance formed at the interface between the adhering microglia and/or astrocytes and the PPMP platform rather than across the scar tissue. These observations suggest that the prevention of both astrocytes and microglia adhesion to the electrodes is required to improve FP recording quality and yield.

scholarly journals Immunobiology and Application of Aloe vera-Based Scaffolds in Tissue Engineering

2021 ◽  
Vol 22 (4) ◽  
pp. 1708
Author(s):  
Saeedeh Darzi ◽  
Kallyanashis Paul ◽  
Shanilka Leitan ◽  
Jerome A. Werkmeister ◽  
Shayanti Mukherjee
Keyword(s):  
Tissue Engineering ◽  
Foreign Body ◽  
Scientific Evidence ◽  
Aloe Vera ◽  
Material Design ◽  
Foreign Body Response ◽  
The Body ◽  
Design Strategies ◽  
Immunomodulatory Effects ◽  
Body Response

Aloe vera (AV), a succulent plant belonging to the Liliaceae family, has been widely used for biomedical and pharmaceutical application. Its popularity stems from several of its bioactive components that have anti-oxidant, anti-microbial, anti-inflammatory and even immunomodulatory effects. Given such unique multi-modal biological impact, AV has been considered as a biomaterial for regenerative medicine and tissue engineering applications, where tissue repair and neo-angiogenesis are vital. This review outlines the growing scientific evidence that demonstrates the advantage of AV as tissue engineering scaffolds. We particularly highlight the recent advances in the application of AV-based scaffolds. From a tissue engineering perspective, it is pivotal that the implanted scaffolds strike an appropriate foreign body response to be well-accepted in the body without complications. Herein, we highlight the key cellular processes that regulate the foreign body response to implanted scaffolds and underline the immunomodulatory effects incurred by AV on the innate and adaptive system. Given that AV has several beneficial components, we discuss the importance of delving deeper into uncovering its action mechanism and thereby improving material design strategies for better tissue engineering constructs for biomedical applications.

Motor learning on postural control using auditory biofeedback training

Impact ◽  
2021 ◽  
Vol 2021 (8) ◽  
pp. 58-60
Author(s):  
Naoya Hasegawa ◽  
Tadayoshi Asaka
Keyword(s):  
Postural Control ◽  
Physical Therapists ◽  
Biofeedback Training ◽  
Motor Disorders ◽  
New Methods ◽  
3D Motion Analysis ◽  
Technological Advances ◽  
Sensory Modalities ◽  
The Central Nervous System ◽  
Training Exercises

Motor disorders are characterised by damage to the central nervous system, which subsequently affects muscles, motor skills and brain function. People with motor disorders can suffer injury as a result of falls and recovery from falls can be challenging. Augmented biofeedback modalities is an important tool used in physical therapy, providing individuals with biofeedback that helps guide them through the therapy. Biofeedback modalities have been designed for most of our senses, including auditory, visual and haptic and advances in technology have meant that biofeedback therapy can make use of wearable technology and future advances are expected to further assist. Therefore, it will be key to determine which biofeedback method works best for different training exercises and conditions in order to maximise the benefits of technological advances. Dr Naoya Hasegawa and Professor Tadayoshi Asaka are investigating which biofeedback method works best for different therapies. Their goal is to understand the characteristics of sensory modalities used for biofeedback training in order to help physical therapists determine appropriate approaches for different individuals. The researchers are currently investigating postural control with a view to defining the characteristics of postural control during walking and standing and developing new methods to enhance or improve it. This work involves the use of force plates, 3D motion analysis systems and electromyograms.

scholarly journals Functional approach of the central nervous system (CNS) based on technological advances: from computers to nanotechnology

2008 ◽  
Vol 7 (S1) ◽  
Author(s):  
Katerina Chatzikallia ◽  
Magdalini Krommyda ◽  
Vasiliki Petropoulou ◽  
Konstantinos Mouratidis ◽  
Maria Prospathopoulou ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional Approach ◽  
Technological Advances ◽  
The Central Nervous System

scholarly journals The Active Electrode in the Living Brain: The Response of the Brain Parenchyma to Chronically Implanted Deep Brain Stimulation Electrodes

2020 ◽  
Author(s):  
Judith Evers ◽  
Madeleine Lowery
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Foreign Body Response ◽  
Surrounding Tissue ◽  
Active Electrode ◽  
Fibrous Sheath ◽  
Tissue Impedance ◽  
Implanted Electrodes ◽  
Postmortem Studies ◽  
Deep Brain

Abstract BACKGROUND Deep brain stimulation is an established symptomatic surgical therapy for Parkinson disease, essential tremor, and a number of other movement and neuropsychiatric disorders. The well-established foreign body response around implanted electrodes is marked by gliosis, neuroinflammation, and neurodegeneration. However, how this response changes with the application of chronic stimulation is less well-understood. OBJECTIVE To integrate the most recent evidence from basic science, patient, and postmortem studies on the effect of such an “active” electrode on the parenchyma of the living brain. METHODS A thorough and in-part systematic literature review identified 49 papers. RESULTS Increased electrode-tissue impedance is consistently observed in the weeks following electrode implantation, stabilizing at approximately 3 to 6 mo. Lower impedance values are observed around stimulated implanted electrodes when compared with unstimulated electrodes. A temporary reduction in impedance has also been observed in response to stimulation in nonhuman primates. Postmortem studies from patients confirm the presence of a fibrous sheath, astrocytosis, neuronal loss, and neuroinflammation in the immediate vicinity of the electrode. When comparing stimulated and unstimulated electrodes directly, there is some evidence across animal and patient studies of altered neurodegeneration and neuroinflammation around stimulated electrodes. CONCLUSION Establishing how stimulation influences the electrical and histological properties of the surrounding tissue is critical in understanding how these factors contribute to DBS efficacy, and in controlling symptoms and side effects. Understanding these complex issues will aid in the development of future neuromodulation systems that are optimized for the tissue environment and required stimulation protocols.

The Development of Pneumostrongylus tenuis in the Central Nervous System of White-tailed Deer

1965 ◽  
Vol 2 (4) ◽  
pp. 360-379 ◽  
Author(s):  
Roy C. Anderson
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Medulla Oblongata ◽  
Grey Matter ◽  
Plasma Cells ◽  
Central Canal ◽  
Surrounding Tissue ◽  
Parasite Relationship ◽  
Central Nervous Systems ◽  
The Central Nervous System

The central nervous systems of five fawns (Odocoileus virginianus borealis), infected experimentally with Pneumostrongylus tenuis, were studied histologically 10, 20, 25, 30, and 40 days after infection. In the 10–30 day fawns young developing worms were found in dorsal horns of the grey matter of all regions of the spinal cord. A few worms were found in white matter and in the medulla oblongata. In the fawn autopsied 40 days after infection all but one of about 25 worms found were in the subdural space. Worms in the grey matter usually lay in cell-free tunnels surrounded by compressed neural tissue. There was little reaction of, or cellular infiltration in, surrounding tissue. Malacia was absent in all parts of grey matter. The central canal was normal and the brain, other than the medulla oblongata, was not involved. In the white matter, scattered single myelin sheath degeneration as well as degeneration and disappearance of axis cylinders were common. Occasionally there were tiny malacic areas in white matter, especially near worms. Infiltrations of eosinophils, lymphocytes, and plasma cells were commonly observed in and on the dura mater, the epineurium, ganglion capsules, and other tissues of the epidural space. The relative dearth of histopathologic findings helps to explain the rarity and slightness of neurologic signs in infected fawns and is indicative perhaps of a long and well established host-parasite relationship. This is in contrast to the situation in moose (Alces a. americana) where severe traumatic damage to the spinal cord by P. tenuis is associated with ataxia and paralysis.

scholarly journals Rapid, widespread, and longlasting induction of nestin contributes to the generation of glial scar tissue after CNS injury.

1995 ◽  
Vol 131 (2) ◽  
pp. 453-464 ◽  
Author(s):  
J Frisén ◽  
C B Johansson ◽  
C Török ◽  
M Risling ◽  
U Lendahl
Keyword(s):  
Spinal Cord ◽  
Scar Tissue ◽  
Central Canal ◽  
Glial Scar ◽  
Reactive Astrocytes ◽  
Spatiotemporal Pattern ◽  
Cns Injury ◽  
Neuronal Regeneration ◽  
Nestin Expression ◽  
The Central Nervous System

Neuronal regeneration does generally not occur in the central nervous system (CNS) after injury, which has been attributed to the generation of glial scar tissue. In this report we show that the composition of the glial scar after traumatic CNS injury in rat and mouse is more complex than previously assumed: expression of the intermediate filament nestin is induced in reactive astrocytes. Nestin induction occurs within 48 hours in the spinal cord both at the site of lesion and in degenerating tracts and lasts for at least 13 months. Nestin expression is induced with similar kinetics in the crushed optic nerve. In addition to the expression in reactive astrocytes, we also observed nestin induction within 48 hours after injury in cells close to the central canal in the spinal cord, while nestin expressing cells at later timepoints were found progressively further out from the central canal. This dynamic pattern of nestin induction after injury was mimicked by lacZ expressing cells in nestin promoter/lacZ transgenic mice, suggesting that defined nestin regulatory regions mediate the injury response. We discuss the possibility that the spatiotemporal pattern of nestin expression reflects a population of nestin positive cells, which proliferates and migrates from a region close to the central canal to the site of lesion in response to injury.

scholarly journals The Granule Size Mediates the In Vivo Foreign Body Response and the Integration Behavior of Bone Substitutes

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7372
Author(s):  
Manuel Abels ◽  
Said Alkildani ◽  
Annica Pröhl ◽  
Xin Xiong ◽  
Rumen Krastev ◽  
...  
Keyword(s):  
Granulation Tissue ◽  
Bone Substitute ◽  
Degradation Process ◽  
Bone Substitutes ◽  
Granule Size ◽  
Foreign Body Response ◽  
Surrounding Tissue ◽  
Bony Tissue ◽  
Tissue Integration

The physicochemical properties of synthetically produced bone substitute materials (BSM) have a major impact on biocompatibility. This affects bony tissue integration, osteoconduction, as well as the degradation pattern and the correlated inflammatory tissue responses including macrophages and multinucleated giant cells (MNGCs). Thus, influencing factors such as size, special surface morphologies, porosity, and interconnectivity have been the subject of extensive research. In the present publication, the influence of the granule size of three identically manufactured bone substitute granules based on the technology of hydroxyapatite (HA)-forming calcium phosphate cements were investigated, which includes the inflammatory response in the surrounding tissue and especially the induction of MNGCs (as a parameter of the material degradation). For the in vivo study, granules of three different size ranges (small = 0.355–0.5 mm; medium = 0.5–1 mm; big = 1–2 mm) were implanted in the subcutaneous connective tissue of 45 male BALB/c mice. At 10, 30, and 60 days post implantationem, the materials were explanted and histologically processed. The defect areas were initially examined histopathologically. Furthermore, pro- and anti-inflammatory macrophages were quantified histomorphometrically after their immunohistochemical detection. The number of MNGCs was quantified as well using a histomorphometrical approach. The results showed a granule size-dependent integration behavior. The surrounding granulation tissue has passivated in the groups of the two bigger granules at 60 days post implantationem including a fibrotic encapsulation, while a granulation tissue was still present in the group of the small granules indicating an ongoing cell-based degradation process. The histomorphometrical analysis showed that the number of proinflammatory macrophages was significantly increased in the small granules at 60 days post implantationem. Similarly, a significant increase of MNGCs was detected in this group at 30 and 60 days post implantationem. Based on these data, it can be concluded that the integration and/or degradation behavior of synthetic bone substitutes can be influenced by granule size.

scholarly journals Analysis of Needs For Using Android-Based KPSP Applications In Monitoring The Growth of Together

2021 ◽  
Vol 5 (1) ◽  
pp. 120-125
Author(s):  
Indria Nuraini ◽  
Isabella Hasiana ◽  
Nabila Sayangbati Gamas
Keyword(s):  
Central Nervous System ◽  
Growth And Development ◽  
Development Process ◽  
Sampling Technique ◽  
Functional Abilities ◽  
Cross Sectional ◽  
Technological Advances ◽  
The Central Nervous System ◽  
Analytic Design ◽  
Analyze Data

Background: The development process occurs simultaneously with growth, so that every growth is accompanied by a change in function. Development is the result of the interaction of the maturity of the central nervous system with the organs it affects. The development of the early phase in the form of cognitive, motor, emotional, social, and language functional abilities, is a determinant of the development of the next phase. If there is a deficiency in one aspect of development, it can affect other aspects, so there is a need for early detection of toddler growth and development.Purpose: This study aimed to find out the need for KPSP applications in monitoring the growth and development of toddlers.Methods: This research uses a descriptive-analytic design, cross-sectional approach. The population of this study amounted to 36 respondents, with a purposive sampling technique. The research site is in the Surabaya area by distributing questionnaires in the form of Google Form. Analyze data with Descriptive Analysis.Results: The results of this study stated that before the pandemic monitoring of toddler growth and development was carried out at the Posyandu using the KIA Handbook Instrument/Tool, while during the pandemic monitoring of toddler growth and development could not be carried out directly because of a policy. In this regard, respondents need an instrument/tool that can be used for independent monitoring of growth and development.Conclusion: Monitoring the growth and development of toddlers during the pandemic by utilizing technological advances and being up to date

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