PLoS One Reports:
A Unique Carrier for Deliver of Therapeutic Compounds beyond the Blood-Brain Barrier
Released June 26th, 2008:
A peer reviewed article by the prestigious PLoS ONE (Public Library of Science) & Medical Journal, published on this date a manuscript by Professor Wilfred Jefferies of The University of British Columbia demonstrating that p97 (melanotransferrin) can be used to deliver therapeutics agents such as Doxorubicin® through the Blood Brain Barrier – a significant breakthrough in the potential treatment of a number of neurological diseases. This excerpt from the review highlights the importance of this discovery.
Significance:
This study provides the initial proof of concept for p97 as a carrier capable of shuttling therapeutic levels of drugs from the blood to the brain for the treatment of neurological disorders, including classes of resident and metastatic brain tumors. It may be prudent, therefore, to consider implementation of this novel delivery platform in various clinical settings for therapeutic intervention in acute and chronic neurological diseases.
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List of Member States by WHO region and mortality stratum |
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Global Burden of Neurological Disordersestimates and Projections |
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Conclusions and Recommendations |
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A Unique Carrier for Delivery of Therapeutic Compounds beyond the Blood-Brain Barrier |
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Neurologic Disorders |
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Download the Manuscript |
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A Carrier for the Delivery of Therapeutics’ and other Compounds through the Blood-Brain Barrier
Background: Therapeutic intervention in many neurological diseases is thwarted by the physical obstacle formed by the blood-brain barrier (BBB) that excludes most drugs from entering the brain from the blood. Thus, identifying efficacious modes of drug delivery to the brain remains a ‘‘holy grail’’ in molecular medicine and nanobiotechnology. Brain capillaries, that comprise the BBB, possess an endogenous receptor that ferries an iron-transport protein, termed p97 (melanotransferrin), across the BBB. Here, we explored the hypothesis that therapeutic drugs ‘‘piggybacked’’ as conjugates of p97 can be shuttled across the BBB for treatment of otherwise inoperable brain tumors.
Approach: Human p97 was covalently linked with the chemotherapeutic agents paclitaxel (PTAX) or adriamycin (ADR) and following intravenous injection, measured their penetration into brain tissue and other organs using radio-labeled and fluorescent derivatives of the drugs. In order to establish efficacy of the conjugates, we used nude mouse models to assess p97-drug conjugate activity towards glioma and mammary tumors growing subcutaneously compared to those growing intracranially.
Principal Findings: Bolus-injected p97-drug conjugates and unconjugated p97 traversed brain capillary endothelium within a few minutes and accumulated to 1–2% of the injected by 24 hours. Brain delivery with p97-drug conjugates was quantitatively 10 fold higher than with free drug controls. Furthermore, both free-ADR and p97-ADR conjugates equally inhibited the subcutaneous growth of gliomas growing outside the brain. Evocatively, only p97-ADR conjugates significantly prolonged the survival of animals bearing intracranial gliomas or mammary tumors when compared to similar cumulated doses of free-ADR.
Significance: This study provides the initial proof of concept for p97 as a carrier capable of shuttling therapeutic levels of drugs from the blood to the brain for the treatment of neurological disorders, including classes of resident and metastatic brain tumors. It may be prudent, therefore, to consider implementation of this novel delivery platform in various clinical settings for therapeutic intervention in acute and chronic neurological diseases.
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