1
|
Lan G, Song Q, Luan Y, Cheng Y. Targeted strategies to deliver boron agents across the blood-brain barrier for neutron capture therapy of brain tumors. Int J Pharm 2024; 650:123747. [PMID: 38151104 DOI: 10.1016/j.ijpharm.2023.123747] [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: 09/09/2023] [Revised: 12/21/2023] [Accepted: 12/23/2023] [Indexed: 12/29/2023]
Abstract
Boron neutron capture therapy (BNCT), as an innovative radiotherapy technology, has demonstrated remarkable outcomes when compared to conventional treatments in the management of recurrent and refractory brain tumors. However, in BNCT of brain tumors, the blood-brain barrier is a main stumbling block for restricting the transport of boron drugs to brain tumors, while the tumor targeting and retention of boron drugs also affect the BNCT effect. This review focuses on the recent development of strategies for delivering boron drugs crossing the blood-brain barrier and targeting brain tumors, providing new insights for the development of efficient boron drugs for the treatment of brain tumors.
Collapse
Affiliation(s)
- Gongde Lan
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Qingxu Song
- Department of Radiation Oncology, Boron Neutron Capture Therapy Medical Center, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Yuxia Luan
- Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Yufeng Cheng
- Department of Radiation Oncology, Boron Neutron Capture Therapy Medical Center, Qilu Hospital of Shandong University, Jinan, Shandong, China.
| |
Collapse
|
2
|
Power EA, Rechberger JS, Gupta S, Schwartz JD, Daniels DJ, Khatua S. Drug delivery across the blood-brain barrier for the treatment of pediatric brain tumors - An update. Adv Drug Deliv Rev 2022; 185:114303. [PMID: 35460714 DOI: 10.1016/j.addr.2022.114303] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/09/2022] [Accepted: 04/12/2022] [Indexed: 12/14/2022]
Abstract
Even though the last decade has seen a surge in the identification of molecular targets and targeted therapies in pediatric brain tumors, the blood brain barrier (BBB) remains a significant challenge in systemic drug delivery. This continues to undermine therapeutic efficacy. Recent efforts have identified several strategies that can facilitate enhanced drug delivery into pediatric brain tumors. These include invasive methods such as intra-arterial, intrathecal, and convection enhanced delivery and non-invasive technologies that allow for transient access across the BBB, including focused ultrasound and nanotechnology. This review discusses current strategies that are being used to enhance delivery of different therapies across the BBB to the tumor site - a major unmet need in pediatric neuro-oncology.
Collapse
Affiliation(s)
- Erica A Power
- Mayo Clinic Graduate School of Biomedical Sciences, 200 First Street SW, Rochester, MN 55905, United States; Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
| | - Julian S Rechberger
- Mayo Clinic Graduate School of Biomedical Sciences, 200 First Street SW, Rochester, MN 55905, United States; Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
| | - Sumit Gupta
- Department of Pediatric Hematology/Oncology, Roseman University of Health Sciences, Las Vegas, NV 89118, United States
| | - Jonathan D Schwartz
- Department of Pediatric Hematology/Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
| | - David J Daniels
- Department of Neurologic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
| | - Soumen Khatua
- Department of Pediatric Hematology/Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States.
| |
Collapse
|
3
|
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
|
4
|
Moura RP, Pacheco C, Pêgo AP, des Rieux A, Sarmento B. Lipid nanocapsules to enhance drug bioavailability to the central nervous system. J Control Release 2020; 322:390-400. [PMID: 32247807 DOI: 10.1016/j.jconrel.2020.03.042] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/27/2020] [Accepted: 03/28/2020] [Indexed: 12/15/2022]
Abstract
The central nervous system (CNS), namely the brain, still remains as the hardest area of the human body to achieve adequate concentration levels of most drugs, mainly due to the limiting behavior of its physical and biological defenses. Lipid nanocapsules emerge as a versatile platform to tackle those barriers, and efficiently delivery different drug payloads due to their numerous advantages. They can be produced in a fast, solvent-free and scalable-up process, and their properties can be fine-tuned for to make an optimal brain drug delivery vehicle. Moreover, lipid nanocapsule surface modification can further improve their bioavailability towards the central nervous system. Coupling these features with alternative delivery methods that stem to disrupt or fully circumvent the blood-brain barrier may fully harness the therapeutic advance that lipid nanocapsules can supply to current treatment options. Thus, this review intends to critically address the development of lipid nanocapsules, as well as to highlight the key features that can be modulated to ameliorate their properties towards the central nervous system delivery, mainly through intravenous methods, and how the pathological microenvironment of the CNS can be taken advantage of. The different routes to promote drug delivery towards the brain parenchyma are also discussed, as well as the synergetic effect that can be obtained by combining modified lipid nanocapsules with new/smart administration routes.
Collapse
Affiliation(s)
- Rui Pedro Moura
- I3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Catarina Pacheco
- I3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Ana Paula Pêgo
- I3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; FEUP - Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - Anne des Rieux
- Université Catholique de Louvain, Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Avenue E. Mounier 73, 1200 Brussels, Belgium
| | - Bruno Sarmento
- I3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; CESPU - Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra 1317, 4585-116 Gandra, Portugal.
| |
Collapse
|
5
|
D’Amico RS, Neira JA, Yun J, Alexiades NG, Banu M, Englander ZK, Kennedy BC, Ung TH, Rothrock RJ, Romanov A, Guo X, Zhao B, Sonabend AM, Canoll P, Bruce JN. Validation of an effective implantable pump-infusion system for chronic convection-enhanced delivery of intracerebral topotecan in a large animal model. J Neurosurg 2019; 133:614-623. [PMID: 31374547 PMCID: PMC7227320 DOI: 10.3171/2019.3.jns1963] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/04/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Intracerebral convection-enhanced delivery (CED) has been limited to short durations due to a reliance on externalized catheters. Preclinical studies investigating topotecan (TPT) CED for glioma have suggested that prolonged infusion improves survival. Internalized pump-catheter systems may facilitate chronic infusion. The authors describe the safety and utility of long-term TPT CED in a porcine model and correlation of drug distribution through coinfusion of gadolinium. METHODS Fully internalized CED pump-catheter systems were implanted in 12 pigs. Infusion algorithms featuring variable infusion schedules, flow rates, and concentrations of a mixture of TPT and gadolinium were characterized over increasing intervals from 4 to 32 days. Therapy distribution was measured using gadolinium signal on MRI as a surrogate. A 9-point neurobehavioral scale (NBS) was used to identify side effects. RESULTS All animals tolerated infusion without serious adverse events. The average NBS score was 8.99. The average maximum volume of distribution (Vdmax) in chronically infused animals was 11.30 mL and represented 32.73% of the ipsilateral cerebral hemispheric volume. Vdmax was achieved early during infusions and remained relatively stable despite a slight decline as the infusion reached steady state. Novel tissue TPT concentrations measured by liquid chromatography mass spectroscopy correlated with gadolinium signal intensity on MRI (p = 0.0078). CONCLUSIONS Prolonged TPT-gadolinium CED via an internalized system is safe and well tolerated and can achieve a large Vdmax, as well as maintain a stable Vd for up to 32 days. Gadolinium provides an identifiable surrogate for measuring drug distribution. Extended CED is potentially a broadly applicable and safe therapeutic option in select patients.
Collapse
Affiliation(s)
- Randy S. D’Amico
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Justin A. Neira
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Jonathan Yun
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Nikita G. Alexiades
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Matei Banu
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Zachary K. Englander
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Benjamin C. Kennedy
- Division of Neurosurgery, Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Timothy H. Ung
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Robert J. Rothrock
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Alexander Romanov
- Institute of Comparative Medicine, Columbia University Medical Center, New York, New York
| | - Xiaotao Guo
- Department of Radiology, Columbia University Medical Center, New York, New York
| | - Binsheng Zhao
- Department of Radiology, Columbia University Medical Center, New York, New York
| | - Adam M. Sonabend
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | - Peter Canoll
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Jeffrey N. Bruce
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| |
Collapse
|
6
|
Pang HH, Chen PY, Wei KC, Huang CW, Shiue YL, Huang CY, Yang HW. Convection-Enhanced Delivery of a Virus-Like Nanotherapeutic Agent with Dual-Modal Imaging for Besiegement and Eradication of Brain Tumors. Theranostics 2019; 9:1752-1763. [PMID: 31037136 PMCID: PMC6485197 DOI: 10.7150/thno.30977] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/06/2019] [Indexed: 12/21/2022] Open
Abstract
Convection-enhanced delivery (CED) is a promising technique for infusing a therapeutic agent directly into the brain, bypassing the blood-brain barrier (BBB) with a pressure gradient to increase drug concentration specifically around the brain tumor, thereby enhancing tumor inhibition and limiting the systemic toxicity of chemotherapeutic agents. Herein, we developed a dual-imaging monitored virus-like nanotherapeutic agent as an ideal CED infusate, which can be delivered to specifically besiege and eradicate brain tumors. Methods: We report one-pot fabrication of green-fluorescence virus-like particles (gVLPs) in Escherichia coli (E. coli) for epirubicin (EPI) loading, cell-penetrating peptide (CPP) modification, and 68Ga-DOTA labeling to form a positron emission tomography (PET)-fluorescence dual-imaging monitored virus-like nanotherapeutic agent (68Ga-DOTA labeled EPI@CPP-gVLPs) combined with CED for brain tumor therapy and image tracking. The drug delivery, cytotoxicity, cell uptake, biodistribution, PET-fluorescence imaging and anti-tumor efficacy of the 68Ga-DOTA labeled EPI@CPP-gVLPs were investigated in vitro and in vivo by using U87-MG glioma cell line and U87-MG tumor model. Results: The 68Ga-DOTA-labeled EPI@CPP-gVLPs showed excellent serum stability as an ideal CED infusate (30-40 nm in size), and can be disassembled through proteolytic degradation of the coat protein shell to enable drug release and clearance to minimize long-term accumulation. The present results indicated that 68Ga-DOTA-labeled EPI@CPP-gVLPs can provide a sufficiently high drug payload (39.2 wt% for EPI) and excellent detectability through fluorescence and PET imaging to accurately represent drug distribution during CED infusion. In vivo delivery of the 68Ga-DOTA-labeled EPI@CPP-gVLPs through CED demonstrated that the median survival was prolonged to over 50 days when the mice received two administrations (once per week) compared with the control group (median survival: 26 days). Conclusion: The results clearly indicated that a combination of 68Ga-DOTA-labeled EPI@CPP-gVLPs and CED can serve as a flexible and powerful synergistic treatment in brain tumors without evidence of systemic toxicity.
Collapse
Affiliation(s)
- Hao-Han Pang
- Institute of Medical Science and Technology, National Sun Yat-sen University, 70 Lienhai Rd., Kaohsiung 80424, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-sen University, 70 Lienhai Rd., Kaohsiung 80424, Taiwan
| | - Pin-Yuan Chen
- Department of Neurosurgery, Chang Gung Memorial Hospital, Keelung, 222 Maijin Rd., Keelung 20401, Taiwan
- Community Medicine Research Center and Laboratory Animal Center, Chang Gung Memorial Hospital, Keelung, 222 Maijin Rd., Keelung 20401, Taiwan
- School of Medicine, Chang Gung University, 259 Wenhua 1st Rd., Guishan Dist., Taoyuan 33302, Taiwan
| | - Kuo-Chen Wei
- School of Medicine, Chang Gung University, 259 Wenhua 1st Rd., Guishan Dist., Taoyuan 33302, Taiwan
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, 5 Fuxing St., Guishan Dist., Taoyuan 33305, Taiwan
| | - Chiun-Wei Huang
- Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Linkou, 5 Fuxing St., Guishan Dist., Taoyuan 33305, Taiwan
| | - Yow-Ling Shiue
- Institute of Biomedical Sciences, National Sun Yat-sen University, 70 Lienhai Rd., Kaohsiung 80424, Taiwan
| | - Chiung-Yin Huang
- School of Medicine, Chang Gung University, 259 Wenhua 1st Rd., Guishan Dist., Taoyuan 33302, Taiwan
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, 5 Fuxing St., Guishan Dist., Taoyuan 33305, Taiwan
| | - Hung-Wei Yang
- Institute of Medical Science and Technology, National Sun Yat-sen University, 70 Lienhai Rd., Kaohsiung 80424, Taiwan
| |
Collapse
|
7
|
Abstract
OBJECTIVE To describe the indications for convection-enhanced delivery in the treatment of glioblastoma, highlighting candidates for the delivery method, mechanics of drug delivery, and management of acute and long-term complications. DATA SOURCES A conceptual framework drawn from published literature as well as author's expert experiences. CONCLUSION Convection-enhanced delivery is an established method of delivering new therapies to patients with glioblastoma. Management of both acute and long-term complications is often drug dependent. IMPLICATIONS FOR NURSING PRACTICE Nurses should be able to recognize and manage potential complications during the infusion of agents delivered via convection-enhanced delivery. Post-infusion symptoms may worsen because of immunologic responses related to the drug and management should be directed toward symptom relief and support without interference on the immunologic response.
Collapse
|
8
|
Convection-enhanced delivery of cetuximab conjugated iron-oxide nanoparticles for treatment of spontaneous canine intracranial gliomas. J Neurooncol 2018; 137:653-663. [PMID: 29350351 DOI: 10.1007/s11060-018-2764-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 01/13/2018] [Indexed: 01/04/2023]
Abstract
Cetuximab conjugated iron-oxide nanoparticles (cetuximab-IONPs) have shown both in-vitro and in-vivo anti-tumor efficacy against gliomas. The purpose of this pilot study was to evaluate the safety and potential efficacy of cetuximab-IONPs for treatment of spontaneously occurring intracranial gliomas in canines after convection-enhanced delivery (CED). The use of CED allowed for direct infusion of the cetuximab-IONPs both intratumorally and peritumorally avoiding the blood brain barrier (BBB) and limiting systemic effects. A total of eight dogs participated in the study and only two developed mild post-operative complications, which resolved with medical therapy. All canines underwent a single CED treatment of the cetuximab-IONPs over 3 days and did not receive any further adjuvant treatments. Volumetric analysis showed a median reduction in tumor size of 54.9% by MRI at 1-month (4-6 weeks) follow-up. Five dogs were euthanized due to recurrence of neurological signs other than seizures, two due to recurrent seizures, and one dog died in his sleep. Median survival time after surgery was 248 days (mean 367 days).
Collapse
|
9
|
Convection enhanced delivery of chemotherapeutic drugs into brain tumour. J Control Release 2017; 271:74-87. [PMID: 29274437 DOI: 10.1016/j.jconrel.2017.12.020] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/18/2017] [Accepted: 12/20/2017] [Indexed: 01/17/2023]
Abstract
Convection enhanced delivery (CED) of chemotherapeutic drugs can successfully bypass the blood-brain barrier (BBB). However, the treatment efficacy is significantly variable in clinic owing to the absence of proper drugs and the lack of understanding on the local drug transport. In this study, mathematical modelling is employed to investigate the suitability of six chemotherapeutic drugs from the perspective of intratumoural transport, including fluorouracil, carmustine, cisplatin, methotrexate, doxorubicin and paclitaxel. The convection/diffusion/reaction model coupled with Darcy's law is applied to a 3-D realistic brain tumour model that is extracted from magnetic resonance (MR) images. The modelling demonstrates the advantages of CED in enhancing the convective flow of interstitial fluid and reducing the drug concentration dilution caused by the fluid loss from blood stream in the tumour region around the infusion site. The delivery outcomes of the drug in CED treatments are strongly dependent on its physicochemical properties. Convection is more effective in determining the transport of paclitaxel and methotrexate in brain tumour. Paclitaxel exhibits its superiority in drug penetration and accumulation, resulting in the largest effective delivery volume as compared to the other studied drugs. Nanocarrier and diagnostic ultrasound are able to enhance the drug penetration for achieving improved delivery outcomes. Results obtained in this study can serve as a guide for optimising CED treatment regimens.
Collapse
|
10
|
Lin CY, Li RJ, Huang CY, Wei KC, Chen PY. Controlled release of liposome-encapsulated temozolomide for brain tumour treatment by convection-enhanced delivery. J Drug Target 2017; 26:325-332. [DOI: 10.1080/1061186x.2017.1379526] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Chung-Yin Lin
- Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan, ROC
- Department of Nephrology, Division of Clinical Toxicology, Chang Gung Memorial Hospital, Lin-Kou Medical Center, Taoyuan, ROC
| | - Rui-Jin Li
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, ROC
| | - Chiung-Yin Huang
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, ROC
| | - Kuo-Chen Wei
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, ROC
| | - Pin-Yuan Chen
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou Medical Center and College of Medicine, Chang Gung University, Taoyuan, ROC
| |
Collapse
|
11
|
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
|
12
|
Saito R, Tominaga T. Convection-enhanced Delivery of Therapeutics for Malignant Gliomas. Neurol Med Chir (Tokyo) 2016; 57:8-16. [PMID: 27980285 PMCID: PMC5243160 DOI: 10.2176/nmc.ra.2016-0071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Convection-enhanced delivery (CED) circumvents the blood–brain barrier by delivering agents directly into the tumor and surrounding parenchyma. CED can achieve large volumes of distribution by continuous positive-pressure infusion. Although promising as an effective drug delivery method in concept, the administration of therapeutic agents via CED is not without challenges. Limitations of distribution remain a problem in large brains, such as those of humans. Accurate and consistent delivery of an agent is another challenge associated with CED. Similar to the difficulties caused by immunosuppressive environments associated with gliomas, there are several mechanisms that make effective local drug distribution difficult in malignant gliomas. In this review, methods for local drug application targeting gliomas are discussed with special emphasis on CED. Although early clinical trials have failed to demonstrate the efficacy of CED against gliomas, CED potentially can be a platform for translating the molecular understanding of glioblastomas achieved in the laboratory into effective clinical treatments. Several clinical studies using CED of chemotherapeutic agents are ongoing. Successful delivery of effective agents should prove the efficacy of CED in the near future.
Collapse
Affiliation(s)
- Ryuta Saito
- Department of Neurosurgery, Tohoku University Graduate School of Medicine
| | | |
Collapse
|
13
|
Kim DG, Kim KH, Seo YJ, Yang H, Marcusson EG, Son E, Lee K, Sa JK, Lee HW, Nam DH. Anti-miR delivery strategies to bypass the blood-brain barrier in glioblastoma therapy. Oncotarget 2016; 7:29400-11. [PMID: 27102443 PMCID: PMC5045404 DOI: 10.18632/oncotarget.8837] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/28/2016] [Indexed: 12/19/2022] Open
Abstract
Small non-coding RNAs called miRNAs are key regulators in various biological processes, including tumor initiation, propagation, and metastasis in glioblastoma as well as other cancers. Recent studies have shown the potential for oncogenic miRNAs as therapeutic targets in glioblastoma. However, the application of antisense oligomers, or anti-miRs, to the brain is limited due to the blood-brain barrier (BBB), when administered in the traditional systemic manner. To induce a therapeutic effect in glioblastoma, anti-miR therapy requires a robust and effective delivery system to overcome this obstacle. To bypass the BBB, different delivery administration methods for anti-miRs were evaluated. Stereotaxic surgery was performed to administer anti-Let-7 through intratumoral (ITu), intrathecal (ITh), and intraventricular (ICV) routes, and each method's efficacy was determined by changes in the expression of anti-Let-7 target genes as well as by immunohistochemical analysis. ITu administration of anti-miRs led to a high rate of anti-miR delivery to tumors in the brain by both bolus and continuous administration. In addition, ICV administration, compared with ITu administration, showed a greater distribution of the miR across entire brain tissues. This study suggests that local administration methods are a promising strategy for anti-miR treatment and may overcome current limitations in the treatment of glioblastoma in preclinical animal models.
Collapse
Affiliation(s)
- Dong Geon Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
| | - Kang Ho Kim
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
| | - Yun Jee Seo
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
| | - Heekyoung Yang
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
- Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | | | - Eunju Son
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyoungmin Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
| | - Jason K. Sa
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
| | - Hye Won Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
- Department of Urology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Do-Hyun Nam
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea
- Institute for Refractory Cancer Research, Samsung Medical Center, Seoul, Korea
- Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| |
Collapse
|
14
|
Shoji T, Saito R, Chonan M, Shibahara I, Sato A, Kanamori M, Sonoda Y, Kondo T, Ishii N, Tominaga T. Local convection-enhanced delivery of an anti-CD40 agonistic monoclonal antibody induces antitumor effects in mouse glioma models. Neuro Oncol 2016; 18:1120-8. [PMID: 26917236 DOI: 10.1093/neuonc/now023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 01/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Glioblastoma is one of the most malignant brain tumors in adults and has a dismal prognosis. In a previous report, we reported that CD40, a TNF-R-related cell surface receptor, and its ligand CD40L were associated with glioma outcomes. Here we attempted to activate CD40 signaling in the tumor and determine if it exerted therapeutic efficacy. METHODS CD40 expression was examined in 3 mouse glioma cell lines (GL261, NSCL61, and bRiTs-G3) and 5 human glioma cell lines (U87, U251, U373, T98, and A172). NSCL61 and bRiTs-G3, as glioma stem cells, also expressed the glioma stem cell markers MELK and CD44. In vitro, we demonstrated direct antitumor effects of an anti-CD40 agonistic monoclonal antibody (FGK45) against the cell lines. The efficacy of FGK45 was examined by local convection-enhanced delivery of the monoclonal antibody against each glioma model. RESULTS CD40 was expressed in all mouse and human cell lines tested and was found at the cell membrane of each of the 3 mouse cell lines. FGK45 administration induced significant, direct antitumor effects in vitro. The local delivery of FGK45 significantly prolonged survival compared with controls in the NSCL61 and bRiTs-G3 models, but the effect was not significant in the GL261 model. Increases in apoptosis and CD4(+) and CD8(+) T cell infiltration were observed in the bRiTs-G3 model after FGK45 treatment. CONCLUSIONS Local delivery of FGK45 significantly prolonged survival in glioma stem cell models. Thus, local delivery of this monoclonal antibody is promising for immunotherapy against gliomas.
Collapse
Affiliation(s)
- Takuhiro Shoji
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Ryuta Saito
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Masashi Chonan
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Ichiyo Shibahara
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Aya Sato
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Masayuki Kanamori
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Yukihiko Sonoda
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Toru Kondo
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Naoto Ishii
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan (T.S., R.S., M.C., I.S., A.S., M.K., Y.S., T.T.);Department of Immunology, Tohoku University Graduate School of Medicine, Sendai, Japan (N.I.)Division of Stem Cell Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan (T.K.)
| |
Collapse
|
15
|
Zhang R, Saito R, Mano Y, Sumiyoshi A, Kanamori M, Sonoda Y, Kawashima R, Tominaga T. Convection-enhanced delivery of SN-38-loaded polymeric micelles (NK012) enables consistent distribution of SN-38 and is effective against rodent intracranial brain tumor models. Drug Deliv 2015; 23:2780-2786. [PMID: 26330269 DOI: 10.3109/10717544.2015.1081994] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Convection-enhanced delivery (CED) of therapeutic agents is a promising local delivery technique that has been extensively studied as a treatment for CNS diseases over the last two decades. One continuing challenge of CED is accurate and consistent delivery of the agents to the target. The present study focused on a new type of therapeutic agent, NK012, a novel SN-38-loaded polymeric micelle. Local delivery profiles of NK012 and SN-38 were studied using rodent brain and intracranial rodent brain tumor models. First, the cytotoxicity of NK012 against glioma cell lines was determined in vitro. Proliferations of glioma cells were significantly reduced after exposure to NK012. Then, the distribution and local toxicity after CED delivery of NK012 and SN-38 were evaluated in vivo. Volume of distribution of NK012 after CED was much larger than that of SN-38. Histological examination revealed minimum brain tissue damage in rat brains after delivery of 40 µg NK012 but severe damage with SN-38 at the same dose. Subsequently, the efficacy of NK012 delivered via CED was tested in 9L and U87MG rodent orthotopic brain tumor models. CED of NK012 displayed excellent efficacy in the 9L and U87MG orthotopic brain tumor models. Furthermore, NK012 and gadolinium diamide were co-delivered via CED to monitor the NK012 distribution using MRI. Volume of NK012 distribution evaluated by histology and MRI showed excellent agreement. CED of NK012 represents an effective treatment option for malignant gliomas. MRI-guided CED of NK012 has potential for clinical application.
Collapse
Affiliation(s)
- Rong Zhang
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| | - Ryuta Saito
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| | - Yui Mano
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| | - Akira Sumiyoshi
- b Department of Functional Brain Imaging , Institute of Development, Aging and Cancer, Tohoku University , Sendai , Miyagi , Japan
| | - Masayuki Kanamori
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| | - Yukihiko Sonoda
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| | - Ryuta Kawashima
- b Department of Functional Brain Imaging , Institute of Development, Aging and Cancer, Tohoku University , Sendai , Miyagi , Japan
| | - Teiji Tominaga
- a Department of Neurosurgery , Tohoku University Graduate School of Medicine , Sendai , Miyagi , Japan and
| |
Collapse
|
16
|
Baronzio G, Parmar G, Baronzio M. Overview of Methods for Overcoming Hindrance to Drug Delivery to Tumors, with Special Attention to Tumor Interstitial Fluid. Front Oncol 2015; 5:165. [PMID: 26258072 PMCID: PMC4512202 DOI: 10.3389/fonc.2015.00165] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/06/2015] [Indexed: 12/24/2022] Open
Abstract
Every drug used to treat cancer (chemotherapeutics, immunological, monoclonal antibodies, nanoparticles, radionuclides) must reach the targeted cells through the tumor environment at adequate concentrations, in order to exert their cell-killing effects. For any of these agents to reach the goal cells, they must overcome a number of impediments created by the tumor microenvironment (TME), beginning with tumor interstitial fluid pressure (TIFP), and a multifactorial increase in composition of the extracellular matrix (ECM). A primary modifier of TME is hypoxia, which increases the production of growth factors, such as vascular endothelial growth factor and platelet-derived growth factor. These growth factors released by both tumor cells and bone marrow recruited myeloid cells form abnormal vasculature characterized by vessels that are tortuous and more permeable. Increased leakiness combined with increased inflammatory byproducts accumulates fluid within the tumor mass (tumor interstitial fluid), ultimately creating an increased pressure (TIFP). Fibroblasts are also up-regulated by the TME, and deposit fibers that further augment the density of the ECM, thus, further worsening the TIFP. Increased TIFP with the ECM are the major obstacles to adequate drug delivery. By decreasing TIFP and ECM density, we can expect an associated rise in drug concentration within the tumor itself. In this overview, we will describe all the methods (drugs, nutraceuticals, and physical methods of treatment) able to lower TIFP and to modify ECM used for increasing drug concentration within the tumor tissue.
Collapse
Affiliation(s)
| | - Gurdev Parmar
- Integrated Health Clinic , Fort Langley, BC , Canada
| | - Miriam Baronzio
- Integrative Oncology Section, Medical Center Kines , Milan , Italy
| |
Collapse
|
17
|
Ung TH, Malone H, Canoll P, Bruce JN. Convection-enhanced delivery for glioblastoma: targeted delivery of antitumor therapeutics. CNS Oncol 2015; 4:225-34. [PMID: 26103989 DOI: 10.2217/cns.15.12] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Glioblastoma is the most common primary brain tumor in adults and carries a dismal prognosis despite advancements in treatment. Diffuse tumor infiltration precludes curative surgical resection and necessitates advancements in drug delivery mechanisms. Convection-enhanced delivery (CED) enables continuous local drug delivery for a diverse population of antitumor agents. Importantly, CED circumvents therapeutic challenges posed by the blood-brain barrier by facilitating concentrated local therapeutic drug delivery with limited systemic effects. Here, we present a concise review of properties essential for safe and efficient convection-enhanced drug delivery, as well as a focused review of clinical studies evaluating CED in the treatment of glioblastoma.
Collapse
Affiliation(s)
- Timothy H Ung
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Hani Malone
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| | - Peter Canoll
- Department of Pathology & Cellular Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Jeffrey N Bruce
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY 10032, USA
| |
Collapse
|
18
|
Fakhoury M. Drug delivery approaches for the treatment of glioblastoma multiforme. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2015; 44:1365-73. [PMID: 26046399 DOI: 10.3109/21691401.2015.1052467] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CONTEXT Glioblastoma multiforme (GBM) is by far the most common and aggressive form of glial tumor. It is characterized by a highly proliferative population of cells that invade surrounding tissue and that frequently recur after surgical resection and chemotherapy. Over the last decades, a number of promising novel pharmacological approaches have been investigated, but most of them have failed clinical trials due to some side-effects such as toxicity and poor drug delivery to the brain. The major obstacle in the treatment of GBM is the presence of the blood-brain barrier (BBB). Due to their relatively high molecular weight, most therapeutic drugs fail to cross the BBB from the blood circulation. OBJECTIVE This paper sheds light on the characteristics of GBM and the challenges of current pharmacological treatments. A closer look is given to the role of nanotechnology in the field of drug delivery, and its application in the treatment of brain tumors such as GBM. METHOD For this purpose, effort was made to select the most recent studies using predefined search criteria that included at least one of the following keywords in the PubMed and Medline databases: glioblastoma, drug delivery, blood-brain barrier, nanotechnology, and nanoparticle. CONCLUSION Breakthrough in nanotechnology offers promising applications in cancer therapy and targeted drug delivery. However, more efforts need to be devoted to the development of novel therapeutic strategies that enable the delivery of drugs to desired areas of the brain with limited side-effects and higher therapeutic efficiency.
Collapse
Affiliation(s)
- Marc Fakhoury
- a Department of Neurosciences , University of Montreal , Montreal , QC , Canada
| |
Collapse
|
19
|
Abstract
Eph receptor tyrosine kinases and the corresponding ephrin ligands play a pivotal role in the glioma development and progression. Aberrant protein expression levels of the Eph receptors and ephrins are often associated with higher tumor grade and poor prognosis. Their function in tumorigenesis is complex due to the intricate network of possible co-occurring interactions between neighboring tumor cells and tumor microenvironment. Both Ephs and ephrins localize on the surface of tumor cells, tumor vasculature, glioma stem cells, tumor cells infiltrating brain, and immune cells infiltrating tumors. They can both promote and inhibit tumorigenicity depending on the downstream forward and reverse signalling generated. All the above-mentioned features make the Ephs/ephrins system an intriguing candidate for the development of new therapeutic strategies in glioma treatment. This review will give a general overview on the structure and the function of Ephs and ephrins, with a particular emphasis on the state of the knowledge of their role in malignant gliomas.
Collapse
Affiliation(s)
- Sara Ferluga
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Waldemar Debinski
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
- To whom correspondence should be addressed: Waldemar Debinski, M.D., Ph.D., Director of Brain Tumor Center of Excellence, Thomas K. Hearn Jr. Brain Tumor Research Center, Professor of Neurosurgery, Radiation Oncology, and Cancer Biology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157, Phone: (336) 716-9712, Fax: (336) 713-7639,
| |
Collapse
|