1
|
Arms LM, Duchatel RJ, Jackson ER, Sobrinho PG, Dun MD, Hua S. Current status and advances to improving drug delivery in diffuse intrinsic pontine glioma. J Control Release 2024; 370:835-865. [PMID: 38744345 DOI: 10.1016/j.jconrel.2024.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma - DIPG), is the primary cause of brain tumor-related death in pediatric patients. DIPG is characterized by a median survival of <12 months from diagnosis, harboring the worst 5-year survival rate of any cancer. Corticosteroids and radiation are the mainstay of therapy; however, they only provide transient relief from the devastating neurological symptoms. Numerous therapies have been investigated for DIPG, but the majority have been unsuccessful in demonstrating a survival benefit beyond radiation alone. Although many barriers hinder brain drug delivery in DIPG, one of the most significant challenges is the blood-brain barrier (BBB). Therapeutic compounds must possess specific properties to enable efficient passage across the BBB. In brain cancer, the BBB is referred to as the blood-brain tumor barrier (BBTB), where tumors disrupt the structure and function of the BBB, which may provide opportunities for drug delivery. However, the biological characteristics of the brainstem's BBB/BBTB, both under normal physiological conditions and in response to DIPG, are poorly understood, which further complicates treatment. Better characterization of the changes that occur in the BBB/BBTB of DIPG patients is essential, as this informs future treatment strategies. Many novel drug delivery technologies have been investigated to bypass or disrupt the BBB/BBTB, including convection enhanced delivery, focused ultrasound, nanoparticle-mediated delivery, and intranasal delivery, all of which are yet to be clinically established for the treatment of DIPG. Herein, we review what is known about the BBB/BBTB and discuss the current status, limitations, and advances of conventional and novel treatments to improving brain drug delivery in DIPG.
Collapse
Affiliation(s)
- Lauren M Arms
- Therapeutic Targeting Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia; Paediatric Program, Mark Hughes Foundation Centre for Brain Cancer Research, College of Health, Medicine & Wellbeing, University of Newcastle, Callaghan, NSW, Australia
| | - Ryan J Duchatel
- Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia; Cancer Signalling Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Paediatric Program, Mark Hughes Foundation Centre for Brain Cancer Research, College of Health, Medicine & Wellbeing, University of Newcastle, Callaghan, NSW, Australia
| | - Evangeline R Jackson
- Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia; Cancer Signalling Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Paediatric Program, Mark Hughes Foundation Centre for Brain Cancer Research, College of Health, Medicine & Wellbeing, University of Newcastle, Callaghan, NSW, Australia
| | - Pedro Garcia Sobrinho
- Therapeutic Targeting Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Matthew D Dun
- Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia; Cancer Signalling Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Paediatric Program, Mark Hughes Foundation Centre for Brain Cancer Research, College of Health, Medicine & Wellbeing, University of Newcastle, Callaghan, NSW, Australia
| | - Susan Hua
- Therapeutic Targeting Research Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia; Precision Medicine Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia; Paediatric Program, Mark Hughes Foundation Centre for Brain Cancer Research, College of Health, Medicine & Wellbeing, University of Newcastle, Callaghan, NSW, Australia.
| |
Collapse
|
2
|
Fernando D, Ahmed AU, Williams BRG. Therapeutically targeting the unique disease landscape of pediatric high-grade gliomas. Front Oncol 2024; 14:1347694. [PMID: 38525424 PMCID: PMC10957575 DOI: 10.3389/fonc.2024.1347694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/19/2024] [Indexed: 03/26/2024] Open
Abstract
Pediatric high-grade gliomas (pHGG) are a rare yet devastating malignancy of the central nervous system's glial support cells, affecting children, adolescents, and young adults. Tumors of the central nervous system account for the leading cause of pediatric mortality of which high-grade gliomas present a significantly grim prognosis. While the past few decades have seen many pediatric cancers experiencing significant improvements in overall survival, the prospect of survival for patients diagnosed with pHGGs has conversely remained unchanged. This can be attributed in part to tumor heterogeneity and the existence of the blood-brain barrier. Advances in discovery research have substantiated the existence of unique subgroups of pHGGs displaying alternate responses to different therapeutics and varying degrees of overall survival. This highlights a necessity to approach discovery research and clinical management of the disease in an alternative subtype-dependent manner. This review covers traditional approaches to the therapeutic management of pHGGs, limitations of such methods and emerging alternatives. Novel mutations which predominate the pHGG landscape are highlighted and the therapeutic potential of targeting them in a subtype specific manner discussed. Collectively, this provides an insight into issues in need of transformative progress which arise during the management of pHGGs.
Collapse
Affiliation(s)
- Dasun Fernando
- Centre for Cancer Research, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Afsar U. Ahmed
- Centre for Cancer Research, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Bryan R. G. Williams
- Centre for Cancer Research, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| |
Collapse
|
3
|
Martinez PJ, Green AL, Borden MA. Targeting diffuse midline gliomas: The promise of focused ultrasound-mediated blood-brain barrier opening. J Control Release 2024; 365:412-421. [PMID: 38000663 PMCID: PMC10842695 DOI: 10.1016/j.jconrel.2023.11.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/13/2023] [Accepted: 11/18/2023] [Indexed: 11/26/2023]
Abstract
Diffuse midline gliomas (DMGs), including diffuse intrinsic pontine glioma, have among the highest mortality rates of all childhood cancers, despite recent advancements in cancer therapeutics. This is partly because, unlike some CNS tumors, the blood-brain barrier (BBB) of DMG tumor vessels remains intact. The BBB prevents the permeation of many molecular therapies into the brain parenchyma, where the cancer cells reside. Focused ultrasound (FUS) with microbubbles has recently emerged as an innovative and exciting technology that non-invasively permeabilizes the BBB in a small focal region with millimeter precision. In this review, current treatment methods and biological barriers to treating DMGs are discussed. State-of-the-art FUS-mediated BBB opening is then examined, with a focus on the effects of various ultrasound parameters and the treatment of DMGs.
Collapse
Affiliation(s)
- Payton J Martinez
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO 80303, United States; Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80303, United States.
| | - Adam L Green
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Mark A Borden
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO 80303, United States; Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80303, United States
| |
Collapse
|
4
|
Martinez P, Nault G, Steiner J, Wempe MF, Pierce A, Brunt B, Slade M, Mongin A, Song J, Song KH, Ellens N, Serkova N, Green A, Borden M. MRI-Guided Focused Ultrasound Blood-Brain Barrier Opening Increases Drug Delivery and Efficacy in a Diffuse Midline Glioma Mouse Model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.05.534448. [PMID: 37066205 PMCID: PMC10104021 DOI: 10.1101/2023.04.05.534448] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest pediatric brainstem tumor and is difficult to treat with chemotherapy in part due to the blood-brain barrier (BBB). Focused ultrasound (FUS) and microbubbles (MBs) have been shown to cause BBB disruption (BBBD), allowing larger chemotherapeutics to enter the parenchyma. Panobinostat is an example of a promising in vitro agent in DIPG with poor clinical efficacy due to low BBB penetrance. In this study, we hypothesized that using FUS to disrupt the BBB allows higher concentrations of panobinostat to accumulate in the tumor, providing a therapeutic effect. Mice were orthotopically injected with a patient-derived DMG cell line, BT-245. MRI was used to guide FUS/MB (1.5 MHz, 0.615 MPa PNP, 1 Hz PRF, 10 ms PL, 3 min treatment time) / (25 µL/kg, IV) targeting to the tumor location. In animals receiving panobinostat (10 mg/kg, IP) in combination with FUS/MB, a 3-fold increase in tumor panobinostat concentration was observed, with only insignificant increase of the drug in the forebrain. In mice receiving three weekly treatments, the combination of panobinostat and FUS/MB led to a 71% reduction of tumor volumes by MRI ( p = 0.01). Furthermore, FUS/MB improved the mean survival from 21 to 31 days ( p < 0.0001). Our study demonstrates that FUS-mediated BBBD can increase the delivery of panobinostat to an orthotopic DMG tumor, providing a strong therapeutic effect and increased survival. One Sentence Summary FUS and microbubbles can increase the delivery of panobinostat to a patient-derived xenograft (PDX) orthotopic DMG tumor, providing a strong therapeutic effect and increased survival.
Collapse
|
5
|
AAV vectors applied to the treatment of CNS disorders: Clinical status and challenges. J Control Release 2023; 355:458-473. [PMID: 36736907 DOI: 10.1016/j.jconrel.2023.01.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
In recent years, adeno-associated virus (AAV) has become the most important vector for central nervous system (CNS) gene therapy. AAV has already shown promising results in the clinic, for several CNS diseases that cannot be treated with drugs, including neurodegenerative diseases, neuromuscular diseases, and lysosomal storage disorders. Currently, three of the four commercially available AAV-based drugs focus on neurological disorders, including Upstaza for aromatic l-amino acid decarboxylase deficiency, Luxturna for hereditary retinal dystrophy, and Zolgensma for spinal muscular atrophy. All these studies have provided paradigms for AAV-based therapeutic intervention platforms. AAV gene therapy, with its dual promise of targeting disease etiology and enabling 'long-term correction' of disease processes, has the advantages of immune privilege, high delivery efficiency, tissue specificity, and cell tropism in the CNS. Although AAV-based gene therapy has been shown to be effective in most CNS clinical trials, limitations have been observed in its clinical applications, which are often associated with side effects. In this review, we summarized the therapeutic progress, challenges, limitations, and solutions for AAV-based gene therapy in 14 types of CNS diseases. We focused on viral vector technologies, delivery routes, immunosuppression, and other relevant clinical factors. We also attempted to integrate several hurdles faced in clinical and preclinical studies with their solutions, to seek the best path forward for the application of AAV-based gene therapy in the context of CNS diseases. We hope that these thoughtful recommendations will contribute to the efficient translation of preclinical studies and wide application of clinical trials.
Collapse
|
6
|
Martinez P, Nault G, Steiner J, Wempe MF, Pierce A, Brunt B, Slade M, Song JJ, Mongin A, Song KH, Ellens N, Serkova N, Green AL, Borden M. MRI-guided focused ultrasound blood-brain barrier opening increases drug delivery and efficacy in a diffuse midline glioma mouse model. Neurooncol Adv 2023; 5:vdad111. [PMID: 37795179 PMCID: PMC10547466 DOI: 10.1093/noajnl/vdad111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023] Open
Abstract
Background Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest pediatric brainstem tumor and is difficult to treat with chemotherapy in part due to the blood-brain barrier (BBB). Focused ultrasound (FUS) and microbubbles (MBs) have been shown to cause BBB opening, allowing larger chemotherapeutics to enter the parenchyma. Panobinostat is an example of a promising in vitro agent in DIPG with poor clinical efficacy due to low BBB penetrance. In this study, we hypothesized that using FUS to disrupt the BBB allows higher concentrations of panobinostat to accumulate in the tumor, providing a therapeutic effect. Methods Mice were orthotopically injected with a patient-derived diffuse midline glioma (DMG) cell line, BT245. MRI was used to guide FUS/MB (1.5 MHz, 0.615 MPa peak negative pressure, 1 Hz pulse repetition frequency, 10-ms pulse length, 3 min treatment time)/(25 µL/kg, i.v.) targeting to the tumor location. Results In animals receiving panobinostat (10 mg/kg, i.p.) in combination with FUS/MB, a 3-fold increase in tumor panobinostat concentration was observed, without significant increase of the drug in the forebrain. In mice receiving 3 weekly treatments, the combination of panobinostat and FUS/MB led to a 71% reduction of tumor volumes (P = .01). Furthermore, we showed the first survival benefit from FUS/MB improved delivery increasing the mean survival from 21 to 31 days (P < .0001). Conclusions Our study demonstrates that FUS-mediated BBB disruption can increase the delivery of panobinostat to an orthotopic DMG tumor, providing a strong therapeutic effect and increased survival.
Collapse
Affiliation(s)
- Payton Martinez
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Genna Nault
- Department of Radiology, Animal Imaging Shared Resource, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jenna Steiner
- Department of Radiology, Animal Imaging Shared Resource, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Michael F Wempe
- Department of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Angela Pierce
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Breauna Brunt
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Mathew Slade
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jane J Song
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Andrew Mongin
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, Colorado, USA
| | - Kang-Ho Song
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Nicholas Ellens
- Alpheus Medical, Inc., Chanhassen, Minnesota, USA
- Acertara Acoustic Labs, Longmont, Colorado, USA
| | - Natalie Serkova
- Department of Radiology, Animal Imaging Shared Resource, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Adam L Green
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Mark Borden
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| |
Collapse
|
7
|
Sperring CP, Argenziano MG, Savage WM, Teasley DE, Upadhyayula PS, Winans NJ, Canoll P, Bruce JN. Convection-enhanced delivery of immunomodulatory therapy for high-grade glioma. Neurooncol Adv 2023; 5:vdad044. [PMID: 37215957 PMCID: PMC10195574 DOI: 10.1093/noajnl/vdad044] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
Abstract
The prognosis for glioblastoma has remained poor despite multimodal standard of care treatment, including temozolomide, radiation, and surgical resection. Further, the addition of immunotherapies, while promising in a number of other solid tumors, has overwhelmingly failed in the treatment of gliomas, in part due to the immunosuppressive microenvironment and poor drug penetrance to the brain. Local delivery of immunomodulatory therapies circumvents some of these challenges and has led to long-term remission in select patients. Many of these approaches utilize convection-enhanced delivery (CED) for immunological drug delivery, allowing high doses to be delivered directly to the brain parenchyma, avoiding systemic toxicity. Here, we review the literature encompassing immunotherapies delivered via CED-from preclinical model systems to clinical trials-and explore how their unique combination elicits an antitumor response by the immune system, decreases toxicity, and improves survival among select high-grade glioma patients.
Collapse
Affiliation(s)
- Colin P Sperring
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Michael G Argenziano
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - William M Savage
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Damian E Teasley
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Pavan S Upadhyayula
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Nathan J Winans
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| | - Jeffrey N Bruce
- Department of Neurological Surgery, Columbia University Irving Medical Center/NY-Presbyterian Hospital, New York, New York, USA
| |
Collapse
|
8
|
Foo CY, Munir N, Kumaria A, Akhtar Q, Bullock CJ, Narayanan A, Fu RZ. Medical Device Advances in the Treatment of Glioblastoma. Cancers (Basel) 2022; 14:5341. [PMID: 36358762 PMCID: PMC9656148 DOI: 10.3390/cancers14215341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 07/30/2023] Open
Abstract
Despite decades of research and the growing emergence of new treatment modalities, Glioblastoma (GBM) frustratingly remains an incurable brain cancer with largely stagnant 5-year survival outcomes of around 5%. Historically, a significant challenge has been the effective delivery of anti-cancer treatment. This review aims to summarize key innovations in the field of medical devices, developed either to improve the delivery of existing treatments, for example that of chemo-radiotherapy, or provide novel treatments using devices, such as sonodynamic therapy, thermotherapy and electric field therapy. It will highlight current as well as emerging device technologies, non-invasive versus invasive approaches, and by doing so provide a detailed summary of evidence from clinical studies and trials undertaken to date. Potential limitations and current challenges are discussed whilst also highlighting the exciting potential of this developing field. It is hoped that this review will serve as a useful primer for clinicians, scientists, and engineers in the field, united by a shared goal to translate medical device innovations to help improve treatment outcomes for patients with this devastating disease.
Collapse
Affiliation(s)
- Cher Ying Foo
- Imperial College School of Medicine, Imperial College London, Fulham Palace Rd., London W6 8RF, UK
| | - Nimrah Munir
- QV Bioelectronics Ltd., 1F70 Mereside, Alderley Park, Nether Alderley, Cheshire SK10 4TG, UK
| | - Ashwin Kumaria
- Department of Neurosurgery, Queen’s Medical Centre, Nottingham University Hospitals, Nottingham NG7 2UH, UK
| | - Qasim Akhtar
- QV Bioelectronics Ltd., 1F70 Mereside, Alderley Park, Nether Alderley, Cheshire SK10 4TG, UK
| | - Christopher J. Bullock
- QV Bioelectronics Ltd., 1F70 Mereside, Alderley Park, Nether Alderley, Cheshire SK10 4TG, UK
| | - Ashwin Narayanan
- QV Bioelectronics Ltd., 1F70 Mereside, Alderley Park, Nether Alderley, Cheshire SK10 4TG, UK
| | - Richard Z. Fu
- QV Bioelectronics Ltd., 1F70 Mereside, Alderley Park, Nether Alderley, Cheshire SK10 4TG, UK
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Michael, Smith Building, Dover St., Manchester M13 9PT, UK
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Care Organisation, Northern Care Alliance NHS Foundation Trust, Salford Royal, Stott Lane, Salford M6 8HD, UK
| |
Collapse
|
9
|
Serva SN, Bernstein J, Thompson JA, Kern DS, Ojemann SG. An update on advanced therapies for Parkinson's disease: From gene therapy to neuromodulation. Front Surg 2022; 9:863921. [PMID: 36211256 PMCID: PMC9537763 DOI: 10.3389/fsurg.2022.863921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Advanced Parkinson's disease (PD) is characterized by increasingly debilitating impaired movements that include motor fluctuations and dyskinesias. At this stage of the disease, pharmacological management can result in unsatisfactory clinical benefits and increase the occurrence of adverse effects, leading to the consideration of advanced therapies. The scope of this review is to provide an overview of currently available therapies for advanced PD, specifically levodopa–carbidopa intestinal gel, continuous subcutaneous apomorphine infusion, radiofrequency ablation, stereotactic radiosurgery, MRI-guided focused ultrasound, and deep brain stimulation. Therapies in clinical trials are also discussed, including novel formulations of subcutaneous carbidopa/levodopa, gene-implantation therapies, and cell-based therapies. This review focuses on the clinical outcomes and adverse effects of the various therapies and also considers patient-specific characteristics that may influence treatment choice. This review can equip providers with updated information on advanced therapies in PD to better counsel patients on the available options.
Collapse
Affiliation(s)
- Stephanie N. Serva
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jacob Bernstein
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - John A. Thompson
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Drew S. Kern
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Correspondence: Steven G. Ojemann Drew S. Kern
| | - Steven G. Ojemann
- Department of Neurosurgery, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Correspondence: Steven G. Ojemann Drew S. Kern
| |
Collapse
|
10
|
Larson PS. Improved Delivery Methods for Gene Therapy and Cell Transplantation in Parkinson's Disease. JOURNAL OF PARKINSONS DISEASE 2021; 11:S199-S206. [PMID: 34366372 PMCID: PMC8543258 DOI: 10.3233/jpd-212710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A number of cell transplantation and gene therapy trials have been performed over the last three decades in an effort to restore function in Parkinson’s disease. Much has been learned about optimizing delivery methods for these therapeutics. This is particularly true in gene therapy, which has predominated the clinical trial landscape in recent years; however, cell transplantation for Parkinson’s disease is currently undergoing a renaissance. Innovations such as cannula design, iMRI-guided surgery and an evolution in delivery strategy has radically changed the way investigators approach clinical trial design. Future therapeutic strategies may employ newer delivery methods such as chronically implanted infusion devices and focal opening of the blood brain barrier with focused ultrasound.
Collapse
Affiliation(s)
- Paul S Larson
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| |
Collapse
|
11
|
Van Laar AD, Van Laar VS, San Sebastian W, Merola A, Bradley Elder J, Lonser RR, Bankiewicz KS. An Update on Gene Therapy Approaches for Parkinson's Disease: Restoration of Dopaminergic Function. JOURNAL OF PARKINSONS DISEASE 2021; 11:S173-S182. [PMID: 34366374 PMCID: PMC8543243 DOI: 10.3233/jpd-212724] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
At present there is a significant unmet need for clinically available treatments for Parkinson’s disease (PD) patients to stably restore balance to dopamine network function, leaving patients with inadequate management of symptoms as the disease progresses. Gene therapy is an attractive approach to impart a durable effect on neuronal function through introduction of genetic material to reestablish dopamine levels and/or functionally recover dopaminergic signaling by improving neuronal health. Ongoing clinical gene therapy trials in PD are focused on enzymatic enhancement of dopamine production and/or the restoration of the nigrostriatal pathway to improve dopaminergic network function. In this review, we discuss data from current gene therapy trials for PD and recent advances in study design and surgical approaches.
Collapse
Affiliation(s)
- Amber D Van Laar
- Asklepios BioPharmaceutical, Inc., Columbus, OH, USA.,Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Victor S Van Laar
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Waldy San Sebastian
- Asklepios BioPharmaceutical, Inc., Columbus, OH, USA.,Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Aristide Merola
- Department of Neurology, College of Medicine, the Ohio State University, Columbus, OH, USA
| | - J Bradley Elder
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Russell R Lonser
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA
| | - Krystof S Bankiewicz
- Department of Neurological Surgery, Ohio State University College of Medicine, Columbus, OH, USA.,Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
12
|
D'Amico RS, Aghi MK, Vogelbaum MA, Bruce JN. Convection-enhanced drug delivery for glioblastoma: a review. J Neurooncol 2021; 151:415-427. [PMID: 33611708 DOI: 10.1007/s11060-020-03408-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 01/18/2020] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Convection-enhanced delivery (CED) is a method of targeted, local drug delivery to the central nervous system (CNS) that bypasses the blood-brain barrier (BBB) and permits the delivery of high-dose therapeutics to large volumes of interest while limiting associated systemic toxicities. Since its inception, CED has undergone considerable preclinical and clinical study as a safe method for treating glioblastoma (GBM). However, the heterogeneity of both, the surgical procedure and the mechanisms of action of the agents studied-combined with the additional costs of performing a trial evaluating CED-has limited the field's ability to adequately assess the durability of any potential anti-tumor responses. As a result, the long-term efficacy of the agents studied to date remains difficult to assess. MATERIALS AND METHODS We searched PubMed using the phrase "convection-enhanced delivery and glioblastoma". The references of significant systematic reviews were also reviewed for additional sources. Articles focusing on physiological and physical mechanisms of CED were included as well as technological CED advances. RESULTS We review the history and principles of CED, procedural advancements and characteristics, and outcomes from key clinical trials, as well as discuss the potential future of this promising technique for the treatment of GBM. CONCLUSION While the long-term efficacy of the agents studied to date remains difficult to assess, CED remains a promising technique for the treatment of GBM.
Collapse
Affiliation(s)
- Randy S D'Amico
- Department of Neurological Surgery, Lenox Hill Hospital/Northwell Health, New York, NY, USA.
| | - Manish K Aghi
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | | | - Jeffrey N Bruce
- Department of Neurological Surgery, New York Presbyterian/Columbia University Irving Medical Center, Herbert Irving Comprehensive Cancer Center, New York, NY, USA
| |
Collapse
|
13
|
Piguet F, de Saint Denis T, Audouard E, Beccaria K, André A, Wurtz G, Schatz R, Alves S, Sevin C, Zerah M, Cartier N. The Challenge of Gene Therapy for Neurological Diseases: Strategies and Tools to Achieve Efficient Delivery to the Central Nervous System. Hum Gene Ther 2021; 32:349-374. [PMID: 33167739 DOI: 10.1089/hum.2020.105] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
For more than 10 years, gene therapy for neurological diseases has experienced intensive research growth and more recently therapeutic interventions for multiple indications. Beneficial results in several phase 1/2 clinical studies, together with improved vector technology have advanced gene therapy for the central nervous system (CNS) in a new era of development. Although most initial strategies have focused on orphan genetic diseases, such as lysosomal storage diseases, more complex and widespread conditions like Alzheimer's disease, Parkinson's disease, epilepsy, or chronic pain are increasingly targeted for gene therapy. Increasing numbers of applications and patients to be treated will require improvement and simplification of gene therapy protocols to make them accessible to the largest number of affected people. Although vectors and manufacturing are a major field of academic research and industrial development, there is a growing need to improve, standardize, and simplify delivery methods. Delivery is the major issue for CNS therapies in general, and particularly for gene therapy. The blood-brain barrier restricts the passage of vectors; strategies to bypass this obstacle are a central focus of research. In this study, we present the different ways that can be used to deliver gene therapy products to the CNS. We focus on results obtained in large animals that have allowed the transfer of protocols to human patients and have resulted in the generation of clinical data. We discuss the different routes of administration, their advantages, and their limitations. We describe techniques, equipment, and protocols and how they should be selected for safe delivery and improved efficiency for the next generation of gene therapy trials for CNS diseases.
Collapse
Affiliation(s)
- Françoise Piguet
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| | - Timothée de Saint Denis
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France.,APHP, Department of Pediatric Neurosurgery, Hôpital Necker-Enfants Malades, APHP Centre. Université de Paris, Paris, France
| | - Emilie Audouard
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| | - Kevin Beccaria
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France.,APHP, Department of Pediatric Neurosurgery, Hôpital Necker-Enfants Malades, APHP Centre. Université de Paris, Paris, France
| | - Arthur André
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France.,APHP, Department of Neurosurgery, Hôpitaux Universitaires La Pitié-Salpêtrière, Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Guillaume Wurtz
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| | - Raphael Schatz
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| | - Sandro Alves
- BrainVectis-Askbio France, iPeps Paris Brain Institute, Paris, France
| | - Caroline Sevin
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France.,BrainVectis-Askbio France, iPeps Paris Brain Institute, Paris, France.,APHP, Department of Neurology, Hopital le Kremlin Bicetre, Paris, France
| | - Michel Zerah
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France.,APHP, Department of Pediatric Neurosurgery, Hôpital Necker-Enfants Malades, APHP Centre. Université de Paris, Paris, France
| | - Nathalie Cartier
- NeuroGenCell, INSERM U1127, Paris Brain Institute (ICM), Sorbonne University, CNRS, AP-HP, University Hospital Pitié-Salpêtrière, Paris, France
| |
Collapse
|
14
|
Determinants of Intraparenchymal Infusion Distributions: Modeling and Analyses of Human Glioblastoma Trials. Pharmaceutics 2020; 12:pharmaceutics12090895. [PMID: 32967184 PMCID: PMC7559135 DOI: 10.3390/pharmaceutics12090895] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 01/01/2023] Open
Abstract
Intra-parenchymal injection and delivery of therapeutic agents have been used in clinical trials for brain cancer and other neurodegenerative diseases. The complexity of transport pathways in tissue makes it difficult to envision therapeutic agent distribution from clinical MR images. Computer-assisted planning has been proposed to mitigate risk for inadequate delivery through quantitative understanding of infusion characteristics. We present results from human studies and simulations of intratumoral infusions of immunotoxins in glioblastoma patients. Gd-DTPA and 124I-labeled human serum albumin (124I-HSA) were co-infused with the therapeutic, and their distributions measured in MRI and PET. Simulations were created by modeling tissue fluid mechanics and physiology and suggested that reduced distribution of tracer molecules within tumor is primarily related to elevated loss rates computed from DCE. PET-tracer on the other hand shows that the larger albumin molecule had longer but heterogeneous residence times within the tumor. We found over two orders of magnitude variation in distribution volumes for the same infusion volumes, with relative error ~20%, allowing understanding of even anomalous infusions. Modeling and measurement revealed that key determinants of flow include infusion-induced expansion and loss through compromised BBB. Opportunities are described to improve computer-assisted CED through iterative feedback between simulations and imaging.
Collapse
|
15
|
Królicki L, Kunikowska J, Bruchertseifer F, Koziara H, Królicki B, Jakuciński M, Pawlak D, Rola R, Morgenstern A, Rosiak E, Merlo A. 225Ac- and 213Bi-Substance P Analogues for Glioma Therapy. Semin Nucl Med 2020; 50:141-151. [DOI: 10.1053/j.semnuclmed.2019.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
16
|
Overview of Current Drug Delivery Methods Across the Blood-Brain Barrier for the Treatment of Primary Brain Tumors. CNS Drugs 2020; 34:1121-1131. [PMID: 32965590 PMCID: PMC7658069 DOI: 10.1007/s40263-020-00766-w] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/05/2020] [Indexed: 01/05/2023]
Abstract
Existing drug delivery methods have not led to a significant increase in survival for patients with malignant primary brain tumors. While the combination of conventional therapies consisting of surgery, radiotherapy, and chemotherapy has improved survival for some types of brain tumors (e.g., WNT medulloblastoma), other types of brain tumors (e.g., glioblastoma and diffuse midline glioma) still have a poor prognosis. The reason for the differences in response can be largely attributed to the blood-brain barrier (BBB), a specialized structure at the microvasculature level that regulates the transport of molecules across the blood vessels into the brain parenchyma. This structure hampers the delivery of most chemotherapeutic agents for the treatment of primary brain tumors. Several drug delivery methods such as nanoparticles, convection enhanced delivery, focused ultrasound, intranasal delivery, and intra-arterial delivery have been developed to overcome the BBB in primary brain tumors. However, prognosis of most primary brain tumors still remains poor. The heterogeneity of the BBB in primary brain tumors and the distinct vasculature of tumors make it difficult to design a drug delivery method that targets the entire tumor. Drug delivery methods that combine strategies such as focused ultrasound and nanoparticles might be a more successful approach. However, more research is needed to optimize and develop new drug delivery techniques to improve survival of patients with primary brain tumors.
Collapse
|
17
|
Sudhakar V, Naidoo J, Samaranch L, Bringas JR, Lonser RR, Fiandaca MS, Bankiewicz KS. Infuse-as-you-go convective delivery to enhance coverage of elongated brain targets: technical note. J Neurosurg 2019; 133:530-537. [PMID: 31299656 DOI: 10.3171/2019.4.jns19826] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/29/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To develop and assess a convective delivery technique that enhances the effectiveness of drug delivery to nonspherical brain nuclei, the authors developed an occipital "infuse-as-you-go" approach to the putamen and compared it to the currently used transfrontal approach. METHODS Eleven nonhuman primates received a bilateral putamen injection of adeno-associated virus with 2 mM gadolinium-DTPA by real-time MR-guided convective perfusion via either a transfrontal (n = 5) or occipital infuse-as-you-go (n = 6) approach. RESULTS MRI provided contemporaneous assessment and monitoring of putaminal infusions for transfrontal (2 to 3 infusion deposits) and occipital infuse-as-you-go (stepwise infusions) putaminal approaches. The infuse-as-you-go technique was more efficient than the transfrontal approach (mean 35 ± 1.1 vs 88 ± 8.3 minutes [SEM; p < 0.001]). More effective perfusion of the postcommissural and total putamen was achieved with the infuse-as-you-go versus transfronatal approaches (100-µl infusion volumes; mean posterior commissural coverage 76.2% ± 5.0% vs 32.8% ± 2.9% [p < 0.001]; and mean total coverage 53.5% ± 3.0% vs 38.9% ± 2.3% [p < 0.01]). CONCLUSIONS The infuse-as-you-go approach, paralleling the longitudinal axis of the target structure, provides a more effective and efficient method for convective infusate coverage of elongated, irregularly shaped subcortical brain nuclei.
Collapse
Affiliation(s)
- Vivek Sudhakar
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Jerusha Naidoo
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Lluis Samaranch
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - John R Bringas
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Russell R Lonser
- 2Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Massimo S Fiandaca
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
| | - Krystof S Bankiewicz
- 1Department of Neurological Surgery, University of California, San Francisco, California; and
- 2Department of Neurological Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| |
Collapse
|
18
|
Maximising coverage of brain structures using controlled reflux, convection-enhanced delivery and the recessed step catheter. J Neurosci Methods 2018; 308:337-345. [DOI: 10.1016/j.jneumeth.2018.08.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/14/2018] [Accepted: 08/31/2018] [Indexed: 11/18/2022]
|
19
|
Wahlberg B, Ghuman H, Liu JR, Modo M. Ex vivo biomechanical characterization of syringe-needle ejections for intracerebral cell delivery. Sci Rep 2018; 8:9194. [PMID: 29907825 PMCID: PMC6004017 DOI: 10.1038/s41598-018-27568-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/05/2018] [Indexed: 02/06/2023] Open
Abstract
Intracerebral implantation of cell suspensions is finding its clinical translation with encouraging results in patients with stroke. However, the survival of cells in the brain remains poor. Although the biological potential of neural stem cells (NSCs) is widely documented, the biomechanical effects of delivering cells through a syringe-needle remain poorly understood. We here detailed the biomechanical forces (pressure, shear stress) that cells are exposed to during ejection through different sized needles (20G, 26G, 32G) and syringes (10, 50, 250 µL) at relevant flow rates (1, 5, 10 µL/min). A comparison of 3 vehicles, Phosphate Buffered Saline (PBS), Hypothermosol (HTS), and Pluronic, indicated that less viscous vehicles are favorable for suspension with a high cell volume fraction to minimize sedimentation. Higher suspension viscosity was associated with greater shear stress. Higher flow rates with viscous vehicle, such as HTS reduced viability by ~10% and also produced more apoptotic cells (28%). At 5 µL/min ejection using a 26G needle increased neuronal differentiation for PBS and HTS suspensions. These results reveal the biological impact of biomechanical forces in the cell delivery process. Appropriate engineering strategies can be considered to mitigate these effects to ensure the efficacious translation of this promising therapy.
Collapse
Affiliation(s)
- Brendon Wahlberg
- Departments of Radiology, University of Pittsburgh, Pittsburgh, USA
| | - Harmanvir Ghuman
- Departments of Bioengineering, University of Pittsburgh, Pittsburgh, USA.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Jessie R Liu
- Departments of Bioengineering, University of Pittsburgh, Pittsburgh, USA
| | - Michel Modo
- Departments of Radiology, University of Pittsburgh, Pittsburgh, USA. .,Departments of Bioengineering, University of Pittsburgh, Pittsburgh, USA. .,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, USA. .,Centre for Neural Basis of Cognition, Pittsburgh, PA15203, USA.
| |
Collapse
|
20
|
Abstract
The direct delivery of drugs and other agents into tissue (in contrast to systemic administration) has been used in clinical trials for brain cancer, neurodegenerative diseases and peripheral tumors. However, continuing evidence suggests that clinical efficacy depends on adequate delivery to a target. Inadequate delivery may have doomed otherwise effective drugs, through failure to distinguish drug inefficacy from poor distribution at the target. Conventional pretreatment clinical images of the patient fail to reveal the complexity and diversity of drug transport pathways in tissue. We discuss the richness of these pathways and argue that development and patient treatment can be sped up and improved by: using quantitative as well as 'real-time' imaging; customized simulations using data from that imaging; and device designs that optimize the drug-device combination.
Collapse
|
21
|
Abstract
Convection-enhanced delivery (CED) is a promising technique that generates a pressure gradient at the tip of an infusion catheter to deliver therapeutics directly through the interstitial spaces of the central nervous system. It addresses and offers solutions to many limitations of conventional techniques, allowing for delivery past the blood-brain barrier in a targeted and safe manner that can achieve therapeutic drug concentrations. CED is a broadly applicable technique that can be used to deliver a variety of therapeutic compounds for a diversity of diseases, including malignant gliomas, Parkinson's disease, and Alzheimer's disease. While a number of technological advances have been made since its development in the early 1990s, clinical trials with CED have been largely unsuccessful, and have illuminated a number of parameters that still need to be addressed for successful clinical application. This review addresses the physical principles behind CED, limitations in the technique, as well as means to overcome these limitations, clinical trials that have been performed, and future developments.
Collapse
Affiliation(s)
- A M Mehta
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, 10032, USA
| | - A M Sonabend
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, 10032, USA
| | - J N Bruce
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, 10032, USA.
| |
Collapse
|
22
|
|
23
|
Vermilyea SC, Lu J, Olsen M, Guthrie S, Tao Y, Fekete EM, Riedel MK, Brunner K, Boettcher C, Bondarenko V, Brodsky E, Block WF, Alexander A, Zhang SC, Emborg ME. Real-Time Intraoperative MRI Intracerebral Delivery of Induced Pluripotent Stem Cell-Derived Neurons. Cell Transplant 2016; 26:613-624. [PMID: 27633706 DOI: 10.3727/096368916x692979] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Induced pluripotent stem cell (iPSC)-derived neurons represent an opportunity for cell replacement strategies for neurodegenerative disorders such as Parkinson's disease (PD). Improvement in cell graft targeting, distribution, and density can be key for disease modification. We have previously developed a trajectory guide system for real-time intraoperative magnetic resonance imaging (RT-IMRI) delivery of infusates, such as viral vector suspensions for gene therapy strategies. Intracerebral delivery of iPSC-derived neurons presents different challenges than viral vectors, including limited cell survival if cells are kept at room temperature for prolonged periods of time, precipitation and aggregation of cells in the cannula, and obstruction during injection, which must be solved for successful application of this delivery approach. To develop procedures suitable for RT-IMRI cell delivery, we first performed in vitro studies to tailor the delivery hardware (e.g., cannula) and defined a range of parameters to be applied (e.g., maximal time span allowable between cell loading in the system and intracerebral injection) to ensure cell survival. Then we performed an in vivo study to evaluate the feasibility of applying the system to nonhuman primates. Our results demonstrate that the RT-IMRI delivery system provides valuable guidance, monitoring, and visualization during intracerebral cell delivery that are compatible with cell survival.
Collapse
|
24
|
Lymphatic Clearance of the Brain: Perivascular, Paravascular and Significance for Neurodegenerative Diseases. Cell Mol Neurobiol 2016; 36:181-94. [PMID: 26993512 PMCID: PMC4844641 DOI: 10.1007/s10571-015-0273-8] [Citation(s) in RCA: 261] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/18/2015] [Indexed: 01/04/2023]
Abstract
The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain extracellular fluids, particularly interstitial fluid (ISF) and cerebrospinal fluid (CSF), is not only important for volume regulation, but also for removal of waste products such as amyloid beta (Aβ). CSF plays a special role in clinical medicine, as it is available for analysis of biomarkers for Alzheimer's disease. Despite the lack of a complete anatomical and physiological picture of the communications between the subarachnoid space (SAS) and the brain parenchyma, it is often assumed that Aβ is cleared from the cerebral ISF into the CSF. Recent work suggests that clearance of the brain mainly occurs during sleep, with a specific role for peri- and para-vascular spaces as drainage pathways from the brain parenchyma. However, the direction of flow, the anatomical structures involved and the driving forces remain elusive, with partially conflicting data in literature. The presence of Aβ in the glia limitans in Alzheimer's disease suggests a direct communication of ISF with CSF. Nonetheless, there is also the well-described pathology of cerebral amyloid angiopathy associated with the failure of perivascular drainage of Aβ. Herein, we review the role of the vasculature and the impact of vascular pathology on the peri- and para-vascular clearance pathways of the brain. The different views on the possible routes for ISF drainage of the brain are discussed in the context of pathological significance.
Collapse
|
25
|
Lewis O, Woolley M, Johnson D, Rosser A, Barua NU, Bienemann AS, Gill SS, Evans S. Chronic, intermittent convection-enhanced delivery devices. J Neurosci Methods 2016; 259:47-56. [DOI: 10.1016/j.jneumeth.2015.11.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/28/2015] [Accepted: 11/06/2015] [Indexed: 12/11/2022]
|
26
|
Massensini AR, Ghuman H, Saldin LT, Medberry CJ, Keane TJ, Nicholls FJ, Velankar SS, Badylak SF, Modo M. Concentration-dependent rheological properties of ECM hydrogel for intracerebral delivery to a stroke cavity. Acta Biomater 2015; 27:116-130. [PMID: 26318805 PMCID: PMC4609617 DOI: 10.1016/j.actbio.2015.08.040] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/13/2015] [Accepted: 08/25/2015] [Indexed: 01/09/2023]
Abstract
Biomaterials composed of mammalian extracellular matrix (ECM) promote constructive tissue remodeling with minimal scar tissue formation in many anatomical sites. However, the optimal shape and form of ECM scaffold for each clinical application can vary markedly. ECM hydrogels have been shown to promote chemotaxis and differentiation of neuronal stem cells, but minimally invasive delivery of such scaffold materials to the central nervous system (CNS) would require an injectable form. These ECM materials can be manufactured to exist in fluid phase at room temperature, while forming hydrogels at body temperature in a concentration-dependent fashion. Implantation into the lesion cavity after a stroke could hence provide a means to support endogenous repair mechanisms. Herein, we characterize the rheological properties of an ECM hydrogel composed of urinary bladder matrix (UBM) that influence its delivery and in vivo interaction with host tissue. There was a notable concentration-dependence in viscosity, stiffness, and elasticity; all characteristics important for minimally invasive intracerebral delivery. An efficient MRI-guided injection with drainage of fluid from the cavity is described to assess in situ hydrogel formation and ECM retention at different concentrations (0, 1, 2, 3, 4, and 8mg/mL). Only ECM concentrations >3mg/mL gelled within the stroke cavity. Lower concentrations were not retained within the cavity, but extensive permeation of the liquid phase ECM into the peri-infarct area was evident. The concentration of ECM hydrogel is hence an important factor affecting gelation, host-biomaterial interface, as well intra-lesion distribution. STATEMENT OF SIGNIFICANCE Extracellular matrix (ECM) hydrogel promotes constructive tissue remodeling in many tissues. Minimally invasive delivery of such scaffold materials to the central nervous system (CNS) would require an injectable form that exists in fluid phase at room temperature, while forming hydrogels at body temperature in a concentration-dependent fashion. We here report the rheological characterization of an injectable ECM hydrogel and its concentration-dependent delivery into a lesion cavity formed after a stroke based on MRI-guidance. The concentration of ECM determined its retention within the cavity or permeation into tissue and hence influenced its interaction with the host brain. This study demonstrates the importance of understanding the structure-function relationship of biomaterials to guide particular clinical applications.
Collapse
Affiliation(s)
- Andre R Massensini
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Radiology, Pittsburgh, PA, USA; Universidade Federal de Minas Gerais, Department of Physiology and Biophysics, Belo Horizonte, Brazil
| | - Harmanvir Ghuman
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA
| | - Lindsey T Saldin
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA
| | - Christopher J Medberry
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA
| | - Timothy J Keane
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA
| | - Francesca J Nicholls
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Radiology, Pittsburgh, PA, USA; King's College London, Department of Neuroscience, London, UK
| | - Sachin S Velankar
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Chemical Engineering, Pittsburgh, PA, USA
| | - Stephen F Badylak
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA; University of Pittsburgh, Department of Surgery, Pittsburgh, PA, USA
| | - Michel Modo
- University of Pittsburgh, McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA; University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, USA; University of Pittsburgh, Department of Radiology, Pittsburgh, PA, USA.
| |
Collapse
|
27
|
Brady ML, Raghavan R, Block W, Grabow B, Ross C, Kubota K, Alexander AL, Emborg ME. The Relation between Catheter Occlusion and Backflow during Intraparenchymal Cerebral Infusions. Stereotact Funct Neurosurg 2015; 93:102-109. [PMID: 25721097 DOI: 10.1159/000367665] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 08/18/2014] [Indexed: 11/19/2022]
Abstract
Background/Aims: The distribution of infusate into the brain by convection-enhanced delivery can be affected by backflow along the catheter shaft. This work assesses the following: (1) whether tissue coring and occlusion of the catheter lumen occurs when an open end-port catheter is inserted, (2) whether there is a relationship between intracatheter pressure and backflow, and (3) whether catheter occlusion increases backflow. Methods: Freshly excised monkey brains were used to assess tissue coring and its correlation with the behavior of the line pressure. In vivo infusions of gadolinium solution into monkey putamen at 1 μl/min were conducted with and without a stylet during insertion. The effect of flow during insertion was evaluated in vivo in the pig thalamus. MRI and line pressure were continuously monitored during in vivo infusions. Results: Ex vivo testing showed that open end-port insertions always cored tissue (which temporarily plugs the catheter tip) and increased pressure followed by a rapid fall after its expulsion. Catheter insertion with a stylet in place prevented coring but not flow insertion; neither affected backflow. Conclusion: Open end-port catheters occlude during insertion, which can be prevented by temporarily closing the port with a stylet but not by infusing while inserting. Backflow was not completely prevented by any insertion method. © 2015 S. Karger AG, Basel.
Collapse
|
28
|
Mooney R, Weng Y, Tirughana-Sambandan R, Valenzuela V, Aramburo S, Garcia E, Li Z, Gutova M, Annala AJ, Berlin JM, Aboody KS. Neural stem cells improve intracranial nanoparticle retention and tumor-selective distribution. Future Oncol 2014; 10:401-15. [PMID: 24559447 DOI: 10.2217/fon.13.217] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AIM The purpose of this work is to determine if tumor-tropic neural stem cells (NSCs) can improve the tumor-selective distribution and retention of nanoparticles (NPs) within invasive brain tumors. MATERIALS & METHODS Streptavidin-conjugated, polystyrene NPs are surface-coupled to biotinylated human NSCs. These NPs are large (798 nm), yet when conjugated to tropic cells, they are too large to passively diffuse through brain tissue or cross the blood-tumor barrier. NP distribution and retention was quantified 4 days after injections located either adjacent to an intracerebral glioma, in the contralateral hemisphere, or intravenously. RESULTS & CONCLUSION In all three in vivo injection paradigms, NSC-coupled NPs exhibited significantly improved tumor-selective distribution and retention over free-NP suspensions. These results provide proof-of-principle that NSCs can facilitate the tumor-selective distribution of NPs, a platform useful for improving intracranial drug delivery.
Collapse
Affiliation(s)
- Rachael Mooney
- Department of Neurosciences, Beckman Research Institute at City of Hope, 1500 East Duarte Road, Duarte, CA, 91010, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Upadhyay RK. Drug delivery systems, CNS protection, and the blood brain barrier. BIOMED RESEARCH INTERNATIONAL 2014; 2014:869269. [PMID: 25136634 PMCID: PMC4127280 DOI: 10.1155/2014/869269] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/31/2014] [Accepted: 06/05/2014] [Indexed: 12/12/2022]
Abstract
Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.
Collapse
Affiliation(s)
- Ravi Kant Upadhyay
- Department of Zoology, DDU Gorakhpur University, Gorakhpur 273009, India
| |
Collapse
|
30
|
Emborg ME, Hurley SA, Joers V, Tromp DPM, Swanson CR, Ohshima-Hosoyama S, Bondarenko V, Cummisford K, Sonnemans M, Hermening S, Blits B, Alexander AL. Titer and product affect the distribution of gene expression after intraputaminal convection-enhanced delivery. Stereotact Funct Neurosurg 2014; 92:182-94. [PMID: 24943657 DOI: 10.1159/000360584] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/12/2014] [Indexed: 01/21/2023]
Abstract
BACKGROUND The efficacy and safety of intracerebral gene therapy for brain disorders like Parkinson's disease depends on the appropriate distribution of gene expression. OBJECTIVES To assess whether the distribution of gene expression is affected by vector titer and protein type. METHODS Four adult macaque monkeys seronegative for adeno-associated virus 5 (AAV5) received a 30-µl inoculation of a high- or a low-titer suspension of AAV5 encoding glial cell line-derived neurotrophic factor (GDNF) or green fluorescent protein (GFP) in the right and left ventral postcommissural putamen. The inoculations were conducted using convection-enhanced delivery and intraoperative MRI (IMRI). RESULTS IMRI confirmed targeting and infusion cloud irradiation from the catheter tip into the surrounding area. A postmortem analysis 6 weeks after surgery revealed GFP and GDNF expression ipsilateral to the injection site that had a titer-dependent distribution. GFP and GDNF expression was also observed in fibers in the substantia nigra (SN) pars reticulata (pr), demonstrating anterograde transport. Few GFP-positive neurons were present in the SN pars compacta (pc), possibly by direct retrograde transport of the vector. GDNF was present in many neurons of the SNpc and SNpr. CONCLUSIONS After controlling for target and infusate volume, the intracerebral distribution of the gene product was affected by the vector titer and product biology.
Collapse
Affiliation(s)
- Marina E Emborg
- Preclinical Parkinson's Research Program, Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wis., USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Sillay KA, McClatchy SG, Shepherd BA, Venable GT, Fuehrer TS. Image-guided convection-enhanced delivery into agarose gel models of the brain. J Vis Exp 2014. [PMID: 24894268 DOI: 10.3791/51466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Convection-enhanced delivery (CED) has been proposed as a treatment option for a wide range of neurological diseases. Neuroinfusion catheter CED allows for positive pressure bulk flow to deliver greater quantities of therapeutics to an intracranial target than traditional drug delivery methods. The clinical utility of real time MRI guided CED (rCED) lies in the ability to accurately target, monitor therapy, and identify complications. With training, rCED is efficient and complications may be minimized. The agarose gel model of the brain provides an accessible tool for CED testing, research, and training. Simulated brain rCED allows practice of the mock surgery while also providing visual feedback of the infusion. Analysis of infusion allows for calculation of the distribution fraction (Vd/Vi) allowing the trainee to verify the similarity of the model as compared to human brain tissue. This article describes our agarose gel brain phantom and outlines important metrics during a CED infusion and analysis protocols while addressing common pitfalls faced during CED infusion for the treatment of neurological disease.
Collapse
Affiliation(s)
- Karl A Sillay
- University of Tennessee Health Science Center; Semmes-Murphey Clinic;
| | | | | | | | | |
Collapse
|
32
|
In vivo performance of a microfabricated catheter for intraparenchymal delivery. J Neurosci Methods 2014; 229:76-83. [PMID: 24747536 DOI: 10.1016/j.jneumeth.2014.03.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 11/22/2022]
Abstract
BACKGROUND Convection-enhanced delivery (CED) is currently the only effective clinical technique to deliver biological therapeutic agents that would otherwise not cross the blood-brain barrier. Despite the promise of CED, several technical problems have limited its effectiveness. NEW METHOD Brain infusions into a large mammal (pig) were performed with a catheter that was fabricated using micro-electro-mechanical systems (MEMS) technology (Olbricht et al., 2010). The performance of the catheter was evaluated for infusions at increasing infusion rates. Magnetic resonance (MR) images were acquired in real time to examine the distribution of infused tracers in the parenchyma. RESULTS Both backflow and the distribution of CED of infusates into a variety of cytoarchitectures in porcine brain were quantified. Concentration profiles were determined for several MR contrast reagents as well as a fluorescent dye that are the sizes of small molecules, therapeutic proteins and an adeno-associated virus (AAV). The reagents can serve as surrogates for assessing the convective distribution of active molecules. Infusion rates up to 20μL/min were attained without evidence of backflow along the catheter. COMPARISON WITH EXISTING METHODS The device performed well in terms of both backflow and infusion, superior to that of many studies reported in the literature on other catheters. All infused molecules had comparable ratios of distribution to infusion volumes. CONCLUSIONS The catheter described in this report appears able to target tissue structures with precision, deliver therapeutics at high infusion rates, and resist backflow that can compromise the efficacy of CED therapy. The technology allows development of "smart" catheters for future applications.
Collapse
|
33
|
Osting S, Bennett A, Power S, Wackett J, Hurley SA, Alexander AL, Agbandje-Mckena M, Burger C. Differential effects of two MRI contrast agents on the integrity and distribution of rAAV2 and rAAV5 in the rat striatum. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2014; 1:4. [PMID: 26015943 PMCID: PMC4365861 DOI: 10.1038/mtm.2013.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 10/30/2013] [Indexed: 11/10/2022]
Abstract
Intraoperative magnetic resonance imaging (MRI) has been proposed as a method to optimize intracerebral targeting and for tracking infusate distribution in gene therapy trials for nervous system disorders. We thus investigated possible effects of two MRI contrast agents, gadoteridol (Gd) and galbumin (Gab), on the distribution and levels of transgene expression in the rat striatum and their effect on integrity and stability of recombinant adeno-associated virus (rAAV) particles. MRI studies showed that contrast agent distribution did not predict rAAV distribution. However, green fluorescent protein (GFP) immunoreactivity revealed an increase in distribution of rAAV5-GFP, but not rAAV2-GFP, in the presence of Gd when compared with viral vector injected alone. In contrast, Gab increased the distribution of rAAV2-GFP not rAAV5-GFP. These observations pointed to a direct effect of infused contrast agent on the rAAV particles. Negative-stain electron microscopy (EM), DNAase treatment, and differential scanning calorimetry (DSC) were used to monitor rAAV2 and rAAV5 particle integrity and stability following contrast agent incubation. EMs of rAAV2-GFP and rAAV5-GFP particles pretreated with Gd appear morphologically similar to the untreated sample; however, Gab treatment resulted in surface morphology changes and aggregation. A compromise of particle integrity was suggested by sensitivity of the packaged genome to DNAase treatment following Gab incubation but not Gd for both vectors. However, neither agent significantly affected particle stability when analyzed by DSC. An increase in T m was observed for AAV2 in lactated Ringer's buffer. These results thus highlight potential interactions between MRI contrast agents and AAV that might affect vector distribution and stability, as well as the stabilizing effect of lactated Ringer's solution on AAV2.
Collapse
Affiliation(s)
- Sue Osting
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Antonette Bennett
- Department of Biochemistry, University of Florida , Gainesville, Florida, USA
| | - Shelby Power
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Jordan Wackett
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Samuel A Hurley
- Department of Medical Physics, University of Wisconsin , Madison, Wisconsin, USA
| | - Andrew L Alexander
- Department of Medical Physics, University of Wisconsin , Madison, Wisconsin, USA ; Department of Psychiatry, University of Wisconsin , Madison, Wisconsin, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin , Madison, Wisconsin, USA
| | | | - Corinna Burger
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| |
Collapse
|