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Rerick MT, Chen J, Weber SG. Electroosmotic Perfusion, External Microdialysis: Simulation and Experiment. ACS Chem Neurosci 2023. [PMID: 37379416 PMCID: PMC10360060 DOI: 10.1021/acschemneuro.3c00057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023] Open
Abstract
Information about the rates of hydrolysis of neuropeptides by extracellular peptidases can lead to a quantitative understanding of how the steady-state and transient concentrations of neuropeptides are controlled. We have created a small microfluidic device that electroosmotically infuses peptides into, through, and out of the tissue to a microdialysis probe outside the head. The device is created by two-photon polymerization (Nanoscribe). Inferring quantitative estimates of a rate process from the change in concentration of a substrate that has passed through tissue is challenging for two reasons. One is that diffusion is significant, so there is a distribution of peptide substrate residence times in the tissue. This affects the product yield. The other is that there are multiple paths taken by the substrate as it passes through tissue, so there is a distribution of residence times and thus reaction times. Simulation of the process is essential. The simulations presented here imply that a range of first order rate constants of more than 3 orders of magnitude is measurable and that 5-10 min is required to reach a steady state value of product concentration following initiation of substrate infusion. Experiments using a peptidase-resistant d-amino acid pentapeptide, yaGfl, agree with simulations.
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Affiliation(s)
- Michael T Rerick
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Jun Chen
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Stephen G Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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Matsuura H, Kawakami R, Isoe M, Hoshihara M, Minami Y, Yatsuzuka K, Tsuda T, Murakami M, Suzuki Y, Kawamata J, Imamura T, Hadano S, Watanabe S, Niko Y. NIR-II-Excitable Dye-Loaded Nanoemulsions for Two-Photon Microscopy Imaging of Capillary Blood Vessels in the Entire Hippocampal CA1 Region of Living Mice. ACS APPLIED MATERIALS & INTERFACES 2022; 14:40481-40490. [PMID: 36063083 DOI: 10.1021/acsami.2c03299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
For in vivo two-photon fluorescence microscopy (2PM) imaging, the development of techniques that can improve the observable depth and temporal resolution is an important challenge to address biological and biomedical concerns such as vascular dynamics in the deep brain (typically the hippocampal region) of living animals. Improvements have been achieved through two approaches: an optical approach using a highly tissue-penetrating excitation laser oscillating in the second near-infrared wavelength region (NIR-II, 1100-1350 nm) and a chemical approach employing fluorescent probes with high two-photon brightness (characterized by the product of the two-photon absorption cross section, σ2, and the fluorescence quantum yield, Φ). To integrate these two approaches, we developed a fluorescent dye exhibiting a sufficiently high σ2Φ value of 68 Goeppert-Mayer units at 1100 nm. When a nanoemulsion encapsulating >1000 dye molecules per particle and a 1100 nm laser were employed for 2PM imaging, capillary blood vessels in almost the entire hippocampal CA1 region of the mouse brain (approximately 1.1-1.5 mm below the surface) were clearly visualized at a frame rate of 30 frames s-1 (averaged over eight frames, practically 3.75 frames s-1). This observable depth and frame rate are much higher than those in previous reports on 2PM imaging. Furthermore, this nanoemulsion allowed for the visualization of blood vessels at a depth of 1.8 mm, corresponding to the hippocampal dentate gyrus. These results highlight the advantage of combining bright probes with NIR-II lasers. Our probe is a promising tool for studying the vascular dynamics of living animals and related diseases.
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Affiliation(s)
- Hitomi Matsuura
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
- TOSA Innovative Human Development Programs, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
| | - Ryosuke Kawakami
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Maki Isoe
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
| | - Masaharu Hoshihara
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi-shi, Yamaguchi 753-8512, Japan
| | - Yuya Minami
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi-shi, Yamaguchi 753-8512, Japan
| | - Kazuki Yatsuzuka
- Department of Dermatology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Teruko Tsuda
- Department of Dermatology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Masamoto Murakami
- Department of Dermatology, Graduate School of Medicine, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Yasutaka Suzuki
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi-shi, Yamaguchi 753-8512, Japan
| | - Jun Kawamata
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1, Yoshida, Yamaguchi-shi, Yamaguchi 753-8512, Japan
| | - Takeshi Imamura
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Shingo Hadano
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
| | - Shigeru Watanabe
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
| | - Yosuke Niko
- Research and Education Faculty, Multidisciplinary Science Cluster, Interdisciplinary Science Unit, Kochi University, 2-5-1, Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
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Brain Renin-Angiotensin System as Novel and Potential Therapeutic Target for Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms221810139. [PMID: 34576302 PMCID: PMC8468637 DOI: 10.3390/ijms221810139] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 12/15/2022] Open
Abstract
The activation of the brain renin-angiotensin system (RAS) plays a pivotal role in the pathophysiology of cognition. While the brain RAS has been studied before in the context of hypertension, little is known about its role and regulation in relation to neuronal function and its modulation. Adequate blood flow to the brain as well as proper clearing of metabolic byproducts become crucial in the presence of neurodegenerative disorders such as Alzheimer's disease (AD). RAS inhibition (RASi) drugs that can cross into the central nervous system have yielded unclear results in improving cognition in AD patients. Consequently, only one RASi therapy is under consideration in clinical trials to modify AD. Moreover, the role of non-genetic factors such as hypercholesterolemia in the pathophysiology of AD remains largely uncharacterized, even when evidence exists that it can lead to alteration of the RAS and cognition in animal models. Here we revise the evidence for the function of the brain RAS in cognition and AD pathogenesis and summarize the evidence that links it to hypercholesterolemia and other risk factors. We review existent medications for RASi therapy and show research on novel drugs, including small molecules and nanodelivery strategies that can target the brain RAS with potential high specificity. We hope that further research into the brain RAS function and modulation will lead to innovative therapies that can finally improve AD neurodegeneration.
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Wang T, Kleiven S, Li X. Electroosmosis Based Novel Treatment Approach for Cerebral Edema. IEEE Trans Biomed Eng 2021; 68:2645-2653. [PMID: 33338011 DOI: 10.1109/tbme.2020.3045916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Cerebral edema characterized as an abnormal accumulation of interstitial fluid has not been treated effectively. We propose a novel edema treatment approach to drive edematous fluid out of the brain by direct current utilizing brain tissue's electroosmotic property. METHODS A finite element (FE) head model is developed and employed to assess the feasibility of the approach. First, the capacity of the model for electric field prediction is validated against human experiments. Second, two electrode configurations (S and D-montage) are designed to evaluate the distribution of the electric field, electroosmotic flow (EOF), current density, and temperature across the brain under an applied direct current. RESULTS The S-montage is shown to induce an average EOF velocity of 7e-4 mm/s underneath the anode by a voltage of 15 V, and the D-montage induces a velocity of 9e-4 mm/s by a voltage of 5 V. Meanwhile, the brain temperature in both configurations is below 38 °C, which is within the safety range. Further, the magnitude of EOF is proportional to the electric field, and the EOF direction follows the current flow from anode to cathode. The EOF velocity in the white matter is significantly higher than that in the gray matter under the anode where the fluid is to be drawn out. CONCLUSION The proposed electroosmosis based approach allows alleviating brain edema within the critical time window by direct current. SIGNIFICANCE The approach may be further developed as a new treatment solely or as a complement to existing conventional treatments of edema.
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Wilson RE, Jaquins-Gerstl A, Chen J, Rerick M, Weber SG. Electroosmotic Perfusion-Microdialysis Probe Created by Direct Laser Writing for Quantitative Assessment of Leucine Enkephalin Hydrolysis by Insulin-Regulated Aminopeptidase in Vivo. Anal Chem 2020; 92:14558-14567. [PMID: 32961052 PMCID: PMC11027065 DOI: 10.1021/acs.analchem.0c02799] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
There are many processes that actively alter the concentrations of solutes in the extracellular space. Enzymatic reactions, either by soluble enzymes or membrane-bound ectoenzymes, and uptake or clearance are two such processes. Investigations of ectoenzymatic reactions in vivo is challenging, particularly in the brain. Studies using microdialysis have revealed some qualitative information about what enzymes may be present, but microdialysis is a sampling technique so it is not designed to control conditions such as a substrate concentration outside the probe. Micropush-pull perfusion has been used to determine which nitric oxide synthase enzymes are active in discrete regions of the rat retina. Ectopeptidases are a particularly important class of ectoenzymes. As far as it is known, the extracellular activity of active peptides in the brain is controlled by ectopeptidases. To understand ectopeptidase activity, we developed a physical probe and an accompanying method. The probe has a two-channel source that supplies substrate or substrate plus inhibitor using electroosmotic perfusion (EOP). It also has a microdialysis probe to collect products and unreacted substrate. The method provides quantitative estimates of substrate-to-product conversion and the influence of inhibitors on this process. The quantitative estimates are made possible by including a d-amino acid-containing peptide analog of the substrate in the substrate-containing solution infused. Quantitative analysis of substrate, substrate analog, and products is carried out by quantitative, online capillary liquid chromatography-tandem mass spectrometry. The electroosmotic perfusion-microdialysis probe and associated method were used to determine the effect of the selective inhibitor HFI-419 on insulin-regulated aminopeptidase (EC 3.4.11.3) in the rat neocortex.
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Affiliation(s)
- Rachael E Wilson
- Department of Chemistry University of Pittsburgh Pittsburgh Pennsylvania 15260, United States
| | - Andrea Jaquins-Gerstl
- Department of Chemistry University of Pittsburgh Pittsburgh Pennsylvania 15260, United States
| | - Jun Chen
- Department of Electrical and Computer Engineering, and Petersen Institute of NanoScience and Engineering University of Pittsburgh Pittsburgh Pennsylvania 15260, United States
| | - Michael Rerick
- Department of Chemistry University of Pittsburgh Pittsburgh Pennsylvania 15260, United States
| | - Stephen G Weber
- Department of Chemistry University of Pittsburgh Pittsburgh Pennsylvania 15260, United States
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Chen B, Liu Y, Cai Y, Tang D, Xu S, Gao P, Yu W, Jiao Y, Li W. Hippocampus is more vulnerable to neural damages induced by repeated sevoflurane exposure in the second trimester than other brain areas. Acta Biochim Biophys Sin (Shanghai) 2020; 52:864-874. [PMID: 32515467 DOI: 10.1093/abbs/gmaa060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Indexed: 11/12/2022] Open
Abstract
During the rapidly developing and sensitive period of the central nervous system (CNS), a harmful stimulus may have serious consequences. The effect of anesthetic exposure on the development of the offspring's CNS during pregnancy is still unclear and has been widely concerned. In the present study, we compared the susceptibility of the hippocampus with those of other brain regions in offsprings when the mother mice were exposed to repeated sevoflurane. We found that other than affecting motor sensation, emotion, or social behavior of offspring mice, repeated sevoflurane exposure induced significant memory deficiency. Compared with other brain regions, the hippocampus, which is the key component of the brain serving for learning and memory, was more vulnerable to repeated sevoflurane exposure. We also found that repeated sevoflurane exposure to mother mice could inhibit the axon development of hippocampal neurons. We also predicted that N6-methyladenosine modification of mRNA might play an essential role in the vulnerability of the hippocampus to sevoflurane, while the underlying cellular mechanism needs to be explored in the future. Our study may provide a new perspective for studying the mechanism of hippocampus-specific injury induced by sevoflurane exposure.
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Affiliation(s)
- Bing Chen
- Department of Anesthesiology, The Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
| | - Yanjun Liu
- Department of Anesthesiology, The Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
| | - Yirong Cai
- Department of Anesthesiology, The Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
| | - Dan Tang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Saihong Xu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Po Gao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Yingfu Jiao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China
| | - Wenxian Li
- Department of Anesthesiology, The Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai 200031, China
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Faraji AH, Jaquins-Gerstl AS, Valenta AC, Ou Y, Weber SG. Electrokinetic Convection-Enhanced Delivery of Solutes to the Brain. ACS Chem Neurosci 2020; 11:2085-2093. [PMID: 32559365 PMCID: PMC11059855 DOI: 10.1021/acschemneuro.0c00037] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pressure-induced infusion of solutions into brain tissue is used both in research and in medicine. In medicine, convection enhanced delivery (CED) may be used to deliver agents to localized areas of the brain, such as with gene therapy to functional targets or with deep tumors not readily amenable to resection. However, clinical trials have demonstrated mixed results from CED. CED is limited by a lack of control of the infusion flow path and may cause damage or even neurological deficits due to neuronal distortion. In laboratory research, infusions may be achieved using pressure or using brief bursts of electrical current in iontophoresis. Electrokinetic convection enhanced delivery (ECED) has the potential to deliver drugs and other bioactive substances to local regions in the brain with improved control and lower applied pressures than pressure-based CED. ECED improves control over the infusion profile because the fluid follows the electrical current path and thus can be directed. Both small molecules and macromolecules can be delivered. Here we demonstrate proof-of-principal that electrokinetic (electroosmosis and electrophoresis) convection-enhanced delivery is a viable means for delivering solutes to the brain. We assessed the volume of tissue exposed to the infusates tris(2,2'-bipyridine)ruthenium(II) and fluorescent dextrans. Control of the direction of the transport was also achieved over distances ranging from several hundred micrometers to more than 4 mm. Electrokinetic delivery has the potential to improve control over infusions.
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Affiliation(s)
- Amir H Faraji
- Department of Chemistry, Department of Clinical Translational Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Andrea S Jaquins-Gerstl
- Department of Chemistry, Department of Clinical Translational Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Alec C Valenta
- Department of Chemistry, Department of Clinical Translational Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Yanguang Ou
- Department of Chemistry, Department of Clinical Translational Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Stephen G Weber
- Department of Chemistry, Department of Clinical Translational Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
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Liu J, Yang C, Yang J, Song X, Han W, Xie M, Cheng L, Xie L, Chen H, Jiang L. Effects of early postnatal exposure to fine particulate matter on emotional and cognitive development and structural synaptic plasticity in immature and mature rats. Brain Behav 2019; 9:e01453. [PMID: 31709780 PMCID: PMC6908876 DOI: 10.1002/brb3.1453] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/16/2019] [Accepted: 09/21/2019] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION Fine particulate matter (PM2.5) is closely associated with many neurological disorders including neurodegenerative disease, stroke, and brain tumors. However, the toxic effects of PM2.5 on neurodevelopment remain unclear. In this study, we aimed to determine the neurotoxic effects of early postnatal exposure to PM2.5 in immature and mature rats. METHODS We exposed neonatal rats to PM2.5 (2 or 10 mg/kg body weight) through intranasal instillation from postnatal day (PND) 3-15, once a day. Emotional and cognitive development were evaluated using the elevated plus maze, forced swimming, and Morris water maze tests. Hippocampal tissue was collected and subjected to transmission electron microscopy observation and western blot analysis. RESULTS Rats had lower body weight after exposure to high dose of PM2.5. The behavioral test results indicated that high-dose PM2.5 exposure led to increased anxiety-like symptoms in immature and mature rats, apparent depressive-like behaviors in mature rats, and impaired spatial learning and memory abilities in immature rats, and low-dose PM2.5 exposure increased anxiety-like behaviors in immature rats. Further, high-dose PM2.5 exposure contributed to fewer synapses, thinner postsynaptic density, and shorter active zone in immature and mature rats, and also decreased expressions of synaptophysin (SYP), growth associated protein-43 (GAP43), and postsynaptic density-95 (PSD95) in immature rats, SYP and PSD95 in mature rats. Moreover, low-dose PM2.5 exposure diminished the expression of PSD95 in immature rats. In addition, high-dose PM2.5 exposure reduced brain-derived neurotrophic factor (BDNF) expression and cAMP response element binding protein (CREB) phosphorylation in both immature and mature rats, and low-dose PM2.5 exposure lessened BDNF expression and CREB phosphorylation in immature rats. CONCLUSIONS Our findings indicate that PM2.5 impairs emotional and cognitive development by disrupting structural synaptic plasticity, possibly via the CREB/BDNF signaling pathway.
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Affiliation(s)
- Jie Liu
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Chen Yang
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Jing Yang
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaojie Song
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Wei Han
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Mingdan Xie
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Li Cheng
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Lingling Xie
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Hengsheng Chen
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Li Jiang
- Pediatric Research Institute, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
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Effects of methyl-beta-cyclodextrin on blood-brain barrier permeability in angiotensin II-induced hypertensive rats. Brain Res 2019; 1715:148-155. [DOI: 10.1016/j.brainres.2019.03.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/01/2019] [Accepted: 03/22/2019] [Indexed: 01/06/2023]
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10
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Wu F, Yu P, Mao L. Analytical and Quantitative in Vivo Monitoring of Brain Neurochemistry by Electrochemical and Imaging Approaches. ACS OMEGA 2018; 3:13267-13274. [PMID: 30411032 PMCID: PMC6217607 DOI: 10.1021/acsomega.8b02055] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/02/2018] [Indexed: 05/27/2023]
Abstract
Quantitative monitoring of brain neurochemistry is aimed at an accurate measurement of chemical basal levels and dynamics defining neuronal activities. Analytical tools must be endowed with high selectivity, sensitivity, and spatiotemporal resolution to tackle this task. On one hand, in vivo electroanalysis combined with miniature electrodes has evolved into a minimally invasive method for probing transient events during neural communication and metabolism. On the other hand, noninvasive imaging techniques have been widely adopted in visualizing the neural structure and processes within a population of neurons in two or three dimensions. This perspective will give a concise review of the inspiring frontiers at the interface of neurochemistry and electrochemistry (microvoltammetry, nanoamperometry, galvanic redox potentiometry and ion transport-based sensing) or imaging (super-resolution single nanotube tracking, deep multiphoton microscopy, and free animal imaging). Potential opportunities with these methods and their combinations for multimodal brain analysis will be discussed, intending to draw a brief picture for future neuroscience research.
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Affiliation(s)
- Fei Wu
- Beijing
National Laboratory for Molecular Sciences, Key Laboratory of Analytical
Chemistry for Living Biosystems, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing 100190, China
- University
of CAS, Beijing 100049, China
- CAS
Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
| | - Ping Yu
- Beijing
National Laboratory for Molecular Sciences, Key Laboratory of Analytical
Chemistry for Living Biosystems, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing 100190, China
- University
of CAS, Beijing 100049, China
- CAS
Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
| | - Lanqun Mao
- Beijing
National Laboratory for Molecular Sciences, Key Laboratory of Analytical
Chemistry for Living Biosystems, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing 100190, China
- University
of CAS, Beijing 100049, China
- CAS
Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
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Faraji AH, Jaquins-Gerstl AS, Valenta AC, Weber SG. Electrokinetic infusions into hydrogels and brain tissue: Control of direction and magnitude of solute delivery. J Neurosci Methods 2018; 311:76-82. [PMID: 30308210 DOI: 10.1016/j.jneumeth.2018.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/05/2018] [Accepted: 10/07/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Delivering solutes to a particular region of the brain is currently achieved by iontophoresis for very small volumes and by diffusion from a microdialysis probe for larger volumes. There is a need to deliver solutes to particular areas with more control than is possible with existing methods. NEW METHOD Electrokinetic infusions of solutes were performed into hydrogels and organotypic hippocampal slice cultures. Application of an electrical current creates electroosmotic flow and electrophoresis of a dicationic fluorescent solute through organotypic hippocampal tissue cultures or larger hydrogels. Transport was recorded with fluorescence microscopy imaging in real-time. RESULTS Electrokinetic transport in brain tissue slice cultures and hydrogels occurs along an electrical current path and allows for anisotropic delivery over distances from several hundred micrometers to millimeters. Directional transport may be controlled by altering the current path. The applied electrical current linearly affects the measured solute fluorescence in our model system following infusions. COMPARISON WITH EXISTING METHODS Localized drug delivery involves iontophoresis, with diffusion primarily occurring beyond infusion capillaries under current protocols. Pressure-driven infusions for intraparenchymal targets have also been conducted. Superfusion across a tissue surface provides modest penetration, however is unable to impact deeper targets. In general, control over intraparenchymal drug delivery has been difficult to achieve. Electrokinetic transport provides an alternative to deliver solutes along an electrical current path in tissue. CONCLUSIONS Electrokinetic transport may be applied to living systems for molecular transport. It may be used to improve upon the control of solute delivery over that of pressure-driven transport.
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Affiliation(s)
- Amir H Faraji
- Department of Chemistry, 219 Parkman Avenue, Chevron Science Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 USA; Department of Neurological Surgery, 200 Lothrop Street, UPMC Presbyterian Hospital, Pittsburgh, Pennsylvania, 15213 USA
| | - Andrea S Jaquins-Gerstl
- Department of Chemistry, 219 Parkman Avenue, Chevron Science Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 USA
| | - Alec C Valenta
- Department of Chemistry, 219 Parkman Avenue, Chevron Science Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 USA
| | - Stephen G Weber
- Department of Chemistry, 219 Parkman Avenue, Chevron Science Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 USA.
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Ou Y, Wilson RE, Weber SG. Methods of Measuring Enzyme Activity Ex Vivo and In Vivo. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2018; 11:509-533. [PMID: 29505726 PMCID: PMC6147230 DOI: 10.1146/annurev-anchem-061417-125619] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Enzymes catalyze a variety of biochemical reactions in the body and, in conjunction with transporters and receptors, control virtually all physiological processes. There is great value in measuring enzyme activity ex vivo and in vivo. Spatial and temporal differences or changes in enzyme activity can be related to a variety of natural and pathological processes. Several analytical approaches have been developed to meet this need. They can be classified broadly as methods either based on artificial substrates, with the goal of creating images of diseased tissue, or based on natural substrates, with the goal of understanding natural processes. This review covers a selection of these methods, including optical, magnetic resonance, mass spectrometry, and physical sampling approaches, with a focus on creative chemistry and method development that make ex vivo and in vivo measurements of enzyme activity possible.
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Affiliation(s)
| | - Rachael E Wilson
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA;
| | - Stephen G Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA;
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