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Walter J, Schwarting J, Plesnila N, Terpolilli NA. Influence of Organic Solvents on Secondary Brain Damage after Experimental Traumatic Brain Injury. Neurotrauma Rep 2020; 1:148-156. [PMID: 34223539 PMCID: PMC8240898 DOI: 10.1089/neur.2020.0029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many compounds tested for a possible neuroprotective effect after traumatic brain injury (TBI) are not readily soluble and therefore organic solvents need to be used as a vehicle. It is, however, unclear whether these organic solvents have intrinsic pharmacological effects on secondary brain damage and may therefore interfere with experimental results. Thus, the aim of the current study was to evaluate the effect of four widely used organic solvents, dimethylsulfoxide (DMSO), Miglyol 812 (Miglyol®), polyethyleneglycol 40 (PEG 40), and N-2-methyl-pyrrolidone (NMP) on outcome after TBI in mice. A total of 143 male C57Bl/6 mice were subjected to controlled cortical impact (CCI). Contusion volume, brain edema formation, and neurological function were assessed 24 h after TBI. Test substances or saline were injected intraperitoneally (i.p.) 10 min before CCI. DMSO, Miglyol, and PEG 40 had no effect on post-traumatic contusion volume after CCI; NMP, however, significantly reduced contusion volume and brain edema formation at different concentrations. The use of DMSO, Miglyol, and PEG 40 is unproblematic for studies investigating neuroprotective treatment strategies as they do not influence post-traumatic brain damage. NMP seems to have an intrinsic neuroprotective effect that should be considered when using this agent in pharmacological experiments; further, a putative therapeutic effect of NMP needs to be elucidated in future studies.
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Affiliation(s)
- Johannes Walter
- Institute for Stroke and Dementia Research, Munich University Hospital, Munich, Germany
| | - Julian Schwarting
- Institute for Stroke and Dementia Research, Munich University Hospital, Munich, Germany.,Department of Neurosurgery, Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Munich University Hospital, Munich, Germany
| | - Nicole A Terpolilli
- Institute for Stroke and Dementia Research, Munich University Hospital, Munich, Germany.,Department of Neurosurgery, Munich University Hospital, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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Mendoza K, Derry PJ, Cherian LM, Garcia R, Nilewski L, Goodman JC, Mbye L, Robertson CS, Tour JM, Kent TA. Functional and Structural Improvement with a Catalytic Carbon Nano-Antioxidant in Experimental Traumatic Brain Injury Complicated by Hypotension and Resuscitation. J Neurotrauma 2019; 36:2139-2146. [PMID: 30704349 DOI: 10.1089/neu.2018.6027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hypotension worsens outcome after all severities of traumatic brain injury (TBI), with loss of cerebral autoregulation being a potential contributor. Previously, we demonstrated that intravenous injection of a high capacity catalytic antioxidant, poly(ethylene)glycol conjugated hydrophilic carbon clusters (PEG-HCCs) rapidly restored cerebral perfusion and acutely restored brain oxidative balance in a TBI model complicated by hemorrhagic hypotension without evidence of toxicity. Here, we tested whether these acute effects translated into behavioral and structural benefit. TBI was generated by a cortical contusion impactor in 38 Long Evans rats, followed by blood withdrawal to a target mean arterial pressure of 40 mm Hg. PEG-HCC (2 mg/kg) or diluent was injected intravenously 80 min later at the onset of blood resuscitation followed by another injection 2 h later (doses determined in prior studies). Performance on beam walking (performed on days 1-5) and Morris water maze (MWM) (performed on days 11-15) was tested, and lesion size was determined at the termination. PEG-HCC treatment nearly completely prevented motor dysfunction (p < 0.001 vs. diluent), improved MWM performance (p < 0.001; treatment vs. time interaction) and reduced lesion size by 61% (p = 0.054). Here we show that treatment with PEG-HCCs at a clinically realistic time point (onset of resuscitation) prevented a major portion of the neurological dysfunction induced in this TBI model, and that PEG-HCCs are candidates for additional study as a potential therapeutic agent.
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Affiliation(s)
- Kimberly Mendoza
- 1 Department of Neurology, Baylor College of Medicine, Houston Texas.,2 Department of Chemistry, Rice University, Houston, Texas
| | - Paul J Derry
- 3 Texas A&M College of Medicine-Houston Campus, Houston, Texas
| | | | - Robert Garcia
- 4 Department of Neurosurgery, Baylor College of Medicine, Houston Texas
| | | | - J Clay Goodman
- 4 Department of Neurosurgery, Baylor College of Medicine, Houston Texas.,5 Department of Pathology & Immunology, Baylor College of Medicine, Houston Texas
| | - Lamin Mbye
- 4 Department of Neurosurgery, Baylor College of Medicine, Houston Texas
| | | | - James M Tour
- 2 Department of Chemistry, Rice University, Houston, Texas.,6 The Smalley-Curl Institute, and Rice University, Houston, Texas.,7 Nanocarbon Center, Rice University, Houston, Texas
| | - Thomas A Kent
- 2 Department of Chemistry, Rice University, Houston, Texas.,3 Texas A&M College of Medicine-Houston Campus, Houston, Texas.,8 Department of Neurology, Houston Methodist Hospital and Research Institute, Houston, Texas
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Eles JR, Vazquez AL, Kozai TDY, Cui XT. In vivo imaging of neuronal calcium during electrode implantation: Spatial and temporal mapping of damage and recovery. Biomaterials 2018; 174:79-94. [PMID: 29783119 PMCID: PMC5987772 DOI: 10.1016/j.biomaterials.2018.04.043] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/16/2018] [Accepted: 04/21/2018] [Indexed: 12/13/2022]
Abstract
Implantable electrode devices enable long-term electrophysiological recordings for brain-machine interfaces and basic neuroscience research. Implantation of these devices, however, leads to neuronal damage and progressive neural degeneration that can lead to device failure. The present study uses in vivo two-photon microscopy to study the calcium activity and morphology of neurons before, during, and one month after electrode implantation to determine how implantation trauma injures neurons. We show that implantation leads to prolonged, elevated calcium levels in neurons within 150 μm of the electrode interface. These neurons show signs of mechanical distortion and mechanoporation after implantation, suggesting that calcium influx is related to mechanical trauma. Further, calcium-laden neurites develop signs of axonal injury at 1-3 h post-insert. Over the first month after implantation, physiological neuronal calcium activity increases, suggesting that neurons may be recovering. By defining the mechanisms of neuron damage after electrode implantation, our results suggest new directions for therapies to improve electrode longevity.
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Affiliation(s)
- James R Eles
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
| | - Alberto L Vazquez
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; Radiology, University of Pittsburgh, United States
| | - Takashi D Y Kozai
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; NeuroTech Center of the University of Pittsburgh Brain Institute, United States; Center for Neuroscience, University of Pittsburgh, United States
| | - X Tracy Cui
- Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
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Poellmann MJ, Lee RC. Repair and Regeneration of the Wounded Cell Membrane. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2017. [DOI: 10.1007/s40883-017-0031-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Busingye DS, Turner RJ, Vink R. Combined Magnesium/Polyethylene Glycol Facilitates the Neuroprotective Effects of Magnesium in Traumatic Brain Injury at a Reduced Magnesium Dose. CNS Neurosci Ther 2016; 22:854-9. [PMID: 27421816 DOI: 10.1111/cns.12591] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/07/2016] [Accepted: 06/19/2016] [Indexed: 11/28/2022] Open
Abstract
AIMS While a number of studies have shown that free magnesium (Mg) decline is a feature of traumatic brain injury (TBI), poor central penetration of Mg has potentially limited clinical translation. This study examines whether polyethylene glycol (PEG) facilitates central penetration of Mg after TBI, increasing neuroprotection while simultaneously reducing the dose requirements for Mg. METHODS Rats were exposed to diffuse TBI and administered intravenous MgCl2 either alone (254 μmol/kg or 25.4 μmol/kg) or in combination with PEG (1 g/kg PEG) at 30-min postinjury. Vehicle-treated (saline or PEG) and sham animals served as controls. All animals were subsequently assessed for blood-brain barrier permeability and edema at 5 h, and functional outcome for 1 week postinjury. RESULTS Optimal dose (254 μmol/kg) MgCl2 or Mg PEG significantly improved all outcome parameters compared to vehicle or PEG controls. Intravenous administration of 10% MgCl2 alone (25.4 μmol/kg) had no beneficial effect on any of the outcome parameters, whereas 10% Mg in PEG had the same beneficial effects as optimal dose Mg administration. CONCLUSION Polyethylene glycol facilitates central penetration of Mg following TBI, reducing the concentration of Mg required to confer neuroprotection while simultaneously reducing the risks associated with high peripheral Mg concentration.
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Affiliation(s)
- Diana S Busingye
- Adelaide Centre for Neuroscience Research, School of Medicine, The University of Adelaide, Adelaide, SA, Australia
| | - Renée J Turner
- Adelaide Centre for Neuroscience Research, School of Medicine, The University of Adelaide, Adelaide, SA, Australia
| | - Robert Vink
- Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia.
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Vazquez LC, Hagel E, Willenberg BJ, Dai W, Casanova F, Batich CD, Sarntinoranont M. Polymer-coated cannulas for the reduction of backflow during intraparenchymal infusions. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:2037-2046. [PMID: 22710955 PMCID: PMC3749093 DOI: 10.1007/s10856-012-4652-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 04/14/2012] [Indexed: 06/01/2023]
Abstract
Infusate backflow or leak-back along the cannula track can occur during intraparenchymal infusions resulting in non-specific targeting of therapeutic agents. The occurrence of backflow depends on several variables including cannula radius, infusate flow rate, and tip location. In this study, polymer coatings that swell in situ were developed and tested with in vitro hydrogel experiments for backflow reduction. Coatings were applied to the external cannula surface in a dual layer arrangement with a poly(vinyl alcohol) outer layer atop an inner poly(ethylene oxide) and alginate layer. Once these coated cannulas were inserted and allotted an 8-10 min waiting period for hydration, backflow during infusions of 4.0 μl of a macromolecular tracer (Evans Blue labeled albumin) was reduced significantly under flow rates of 0.3-0.6 μl/min, allowing for more effective distribution within targeted regions. Polymer coating thicknesses before and after hydrations were 0.035 and 0.370 mm, respectively. Also, backflow data was fit to a model to estimate the effective local compressive stress caused by the hydrated polymers. After withdrawal of the cannula from the insertion site, the hydrated polymer coatings remained within the cavity left in the hydrogel tissue phantom and formed a seal at the infusion site that prevented further backflow during needle withdrawal. Ex vivo infusions in excised porcine brain tissues also showed significant backflow reduction while also demonstrating the ability to leave a polymer seal in the tissue cavity after cannula removal. Thus, application of these polymers as needle or cannula coatings offers a potentially simple method to improve targeting for local drug delivery.
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Affiliation(s)
- Louis C. Vazquez
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Erik Hagel
- Department of Mechanical and Aerospace Engineering, University of Florida, 212 MAE-A, Gainesville, FL 32611, USA
| | - Bradley J. Willenberg
- Department of Material Science and Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Wei Dai
- Department of Mechanical and Aerospace Engineering, University of Florida, 212 MAE-A, Gainesville, FL 32611, USA
| | - Fernando Casanova
- Department of Mechanical and Aerospace Engineering, University of Florida, 212 MAE-A, Gainesville, FL 32611, USA
| | - Christopher D. Batich
- Department of Material Science and Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Malisa Sarntinoranont
- Department of Mechanical and Aerospace Engineering, University of Florida, 212 MAE-A, Gainesville, FL 32611, USA
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Garman RH, Jenkins LW, Switzer RC, Bauman RA, Tong LC, Swauger PV, Parks SA, Ritzel DV, Dixon CE, Clark RSB, Bayir H, Kagan V, Jackson EK, Kochanek PM. Blast exposure in rats with body shielding is characterized primarily by diffuse axonal injury. J Neurotrauma 2012; 28:947-59. [PMID: 21449683 DOI: 10.1089/neu.2010.1540] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Blast-induced traumatic brain injury (TBI) is the signature insult in combat casualty care. Survival with neurological damage from otherwise lethal blast exposures has become possible with body armor use. We characterized the neuropathologic alterations produced by a single blast exposure in rats using a helium-driven shock tube to generate a nominal exposure of 35 pounds per square inch (PSI) (positive phase duration ∼ 4 msec). Using an IACUC-approved protocol, isoflurane-anesthetized rats were placed in a steel wedge (to shield the body) 7 feet inside the end of the tube. The left side faced the blast wave (with head-only exposure); the wedge apex focused a Mach stem onto the rat's head. The insult produced ∼ 25% mortality (due to impact apnea). Surviving and sham rats were perfusion-fixed at 24 h, 72 h, or 2 weeks post-blast. Neuropathologic evaluations were performed utilizing hematoxylin and eosin, amino cupric silver, and a variety of immunohistochemical stains for amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba1), ED1, and rat IgG. Multifocal axonal degeneration, as evidenced by staining with amino cupric silver, was present in all blast-exposed rats at all time points. Deep cerebellar and brainstem white matter tracts were most heavily stained with amino cupric silver, with the morphologic staining patterns suggesting a process of diffuse axonal injury. Silver-stained sections revealed mild multifocal neuronal death at 24 h and 72 h. GFAP, ED1, and Iba1 staining were not prominently increased, although small numbers of reactive microglia were seen within areas of neuronal death. Increased blood-brain barrier permeability (as measured by IgG staining) was seen at 24 h and primarily affected the contralateral cortex. Axonal injury was the most prominent feature during the initial 2 weeks following blast exposure, although degeneration of other neuronal processes was also present. Strikingly, silver staining revealed otherwise undetected abnormalities, and therefore represents a recommended outcome measure in future studies of blast TBI.
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Affiliation(s)
- Robert H Garman
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA.
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