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Lam DV, Javadekar A, Patil N, Yu M, Li L, Menendez DM, Gupta AS, Capadona JR, Shoffstall AJ. Platelets and hemostatic proteins are co-localized with chronic neuroinflammation surrounding implanted intracortical microelectrodes. Acta Biomater 2023; 166:278-290. [PMID: 37211307 PMCID: PMC10330779 DOI: 10.1016/j.actbio.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 04/13/2023] [Accepted: 05/02/2023] [Indexed: 05/23/2023]
Abstract
Intracortical microelectrodes induce vascular injury upon insertion into the cortex. As blood vessels rupture, blood proteins and blood-derived cells (including platelets) are introduced into the 'immune privileged' brain tissues at higher-than-normal levels, passing through the damaged blood-brain barrier. Blood proteins adhere to implant surfaces, increasing the likelihood of cellular recognition leading to activation of immune and inflammatory cells. Persistent neuroinflammation is a major contributing factor to declining microelectrode recording performance. We investigated the spatial and temporal relationship of blood proteins fibrinogen and von Willebrand Factor (vWF), platelets, and type IV collagen, in relation to glial scarring markers for microglia and astrocytes following implantation of non-functional multi-shank silicon microelectrode probes into rats. Together with type IV collagen, fibrinogen and vWF augment platelet recruitment, activation, and aggregation. Our main results indicate blood proteins participating in hemostasis (fibrinogen and vWF) persisted at the microelectrode interface for up to 8-weeks after implantation. Further, type IV collagen and platelets surrounded the probe interface with similar spatial and temporal trends as vWF and fibrinogen. In addition to prolonged blood-brain barrier instability, specific blood and extracellular matrix proteins may play a role in promoting the inflammatory activation of platelets and recruitment to the microelectrode interface. STATEMENT OF SIGNIFICANCE: Implanted microelectrodes have substantial potential for restoring function to people with paralysis and amputation by providing signals that feed into natural control algorithms that drive prosthetic devices. Unfortunately, these microelectrodes do not display robust performance over time. Persistent neuroinflammation is widely thought to be a primary contributor to the devices' progressive decline in performance. Our manuscript reports on the highly local and persistent accumulation of platelets and hemostatic blood proteins around the microelectrode interface of brain implants. To our knowledge neuroinflammation driven by cellular and non-cellular responses associated with hemostasis and coagulation has not been rigorously quantified elsewhere. Our findings identify potential targets for therapeutic intervention and a better understanding of the driving mechanisms to neuroinflammation in the brain.
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Affiliation(s)
- Danny V Lam
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anisha Javadekar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | | | - Marina Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Longshun Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Dhariyat M Menendez
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Anirban Sen Gupta
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.
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Savya SP, Li F, Lam S, Wellman SM, Stieger KC, Chen K, Eles JR, Kozai TDY. In vivo spatiotemporal dynamics of astrocyte reactivity following neural electrode implantation. Biomaterials 2022; 289:121784. [PMID: 36103781 PMCID: PMC10231871 DOI: 10.1016/j.biomaterials.2022.121784] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/24/2022] [Accepted: 08/29/2022] [Indexed: 11/02/2022]
Abstract
Brain computer interfaces (BCIs), including penetrating microelectrode arrays, enable both recording and stimulation of neural cells. However, device implantation inevitably causes injury to brain tissue and induces a foreign body response, leading to reduced recording performance and stimulation efficacy. Astrocytes in the healthy brain play multiple roles including regulating energy metabolism, homeostatic balance, transmission of neural signals, and neurovascular coupling. Following an insult to the brain, they are activated and gather around the site of injury. These reactive astrocytes have been regarded as one of the main contributors to the formation of a glial scar which affects the performance of microelectrode arrays. This study investigates the dynamics of astrocytes within the first 2 weeks after implantation of an intracortical microelectrode into the mouse brain using two-photon microscopy. From our observation astrocytes are highly dynamic during this period, exhibiting patterns of process extension, soma migration, morphological activation, and device encapsulation that are spatiotemporally distinct from other glial cells, such as microglia or oligodendrocyte precursor cells. This detailed characterization of astrocyte reactivity will help to better understand the tissue response to intracortical devices and lead to the development of more effective intervention strategies to improve the functional performance of neural interfacing technology.
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Affiliation(s)
- Sajishnu P Savya
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Northwestern University, USA
| | - Fan Li
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA; Computational Modeling & Simulation PhD Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephanie Lam
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steven M Wellman
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kevin C Stieger
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Keying Chen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - James R Eles
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, USA.
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Lindner SC, Yu M, Capadona JR, Shoffstall AJ. A graphical user interface to assess the neuroinflammatory response to intracortical microelectrodes. J Neurosci Methods 2019; 317:141-148. [PMID: 30664915 DOI: 10.1016/j.jneumeth.2019.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Brain-implanted devices, including intracortical microelectrodes, are used in neuroscience applications ranging from research to rehabilitation and beyond. Significant efforts are focused on developing new device designs and insertion strategies that mitigate initial trauma and subsequent neuroinflammation that occurs as a result of implantation. A frequently published metric is the neuroinflammatory response quantified as a function of distance from the interface edge, using fluorescent immunohistochemical markers. NEW METHOD Here, we sought to develop a graphical user interface software in Matlab to provide an objective, repeatable, and easy-to-use method for analyzing fluorescence immunohistochemistry images of neuroinflammation. The user interface allows for efficient batch-processing and review of images, and incorporates zoom and contrast features to improve the accuracy of identifying the 'region of interest' (ROI). RESULTS The software was validated against previously published results and demonstrated equivalent scientific conclusions. Furthermore, a comparison between novice and expert users demonstrated consistency across levels of training and a rapid learning-curve. COMPARISON WITH EXISTING METHOD(S) Existing methods published in the intracortical microelectrode literature include a wide variety of procedures within ImageJ and Matlab. However, specific procedural details are often lacking. CONCLUSIONS The distribution of the methodology may promote efficiency and reproducibility across the field seeking to characterize the tissue response to implanted neural interfaces. It may also serve as a template for researchers seeking to perform other types of histological quantification as a function of distance from an ROI.
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Affiliation(s)
- Sydney C Lindner
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Marina Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jeffrey R Capadona
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, United States; Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States.
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Kozai TD, Eles JR, Vazquez AL, Cui XT. Two-photon imaging of chronically implanted neural electrodes: Sealing methods and new insights. J Neurosci Methods 2016; 258:46-55. [PMID: 26526459 DOI: 10.1016/j.jneumeth.2015.10.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Two-photon microscopy has enabled the visualization of dynamic tissue changes to injury and disease in vivo. While this technique has provided powerful new information, in vivo two-photon chronic imaging around tethered cortical implants, such as microelectrodes or neural probes, present unique challenges. NEW METHOD A number of strategies are described to prepare a cranial window to longitudinally observe the impact of neural probes on brain tissue and vasculature for up to 3 months. RESULTS It was found that silastic sealants limit cell infiltration into the craniotomy, thereby limiting light scattering and preserving window clarity over time. In contrast, low concentration hydrogel sealants failed to prevent cell infiltration and their use at high concentration displaced brain tissue and disrupted probe performance. COMPARISON WITH EXISTING METHOD(S) The use of silastic sealants allows for a suitable imaging window for long term chronic experiments and revealed new insights regarding the dynamic leukocyte response around implants and the nature of chronic BBB leakage in the sub-dural space. CONCLUSION The presented method provides a valuable tool for evaluating the chronic inflammatory response and the performance of emerging implantable neural technologies.
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