Targeting blood-brain barrier sphingolipid signaling reduces basal P-glycoprotein activity and improves drug delivery to the brain

Upregulation of blood-brain barrier (BBB) P-glycoprotein expression causes central nervous system (CNS) pharmacoresistance. However, activation of BBB protein kinase C-β1 (PKC-β1) rapidly reduces basal P-glycoprotein transport activity. We tested whether PKC-β1 activation would reverse CNS drug resistance caused by dioxin acting through aryl hydrocarbon receptor. A selective PKC-β1 agonist abolished the increase in P-glycoprotein activity induced by dioxin in isolated rat brain capillaries and reversed the effect of dioxin on brain uptake of verapamil in dioxin-dosed rats. Thus, targeting BBB PKC-β1 may be an effective strategy to improve drug delivery to the brain, even in drug-resistant individuals.

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Novel Intrinsic Mechanisms of Active Drug Extrusion at the Blood-Brain Barrier: Potential Targets for Enhancing Drug Delivery to the Brain?

Pharmaceutics ◽

10.3390/pharmaceutics12100966 ◽

2020 ◽

Vol 12 (10) ◽

pp. 966

Author(s):

Wolfgang Löscher ◽

Birthe Gericke

Keyword(s):

Drug Delivery ◽

Blood Brain Barrier ◽

Active Drug ◽

Brain Barrier ◽

Brain Diseases ◽

Metabolic Characteristics ◽

P Glycoprotein ◽

Blood Brain ◽

Blood Neutrophils ◽

The Brain

The blood-brain barrier (BBB) limits the pharmacotherapy of several brain disorders. In addition to the structural and metabolic characteristics of the BBB, the ATP-driven, drug efflux transporter P-glycoprotein (Pgp) is a selective gatekeeper of the BBB; thus, it is a primary hindrance to drug delivery into the brain. Here, we review the complex regulation of Pgp expression and functional activity at the BBB with an emphasis on recent studies from our laboratory. In addition to traditional processes such as transcriptional regulation and posttranscriptional or posttranslational modification of Pgp expression and functionality, novel mechanisms such as intra- and intercellular Pgp trafficking and intracellular Pgp-mediated lysosomal sequestration in BBB endothelial cells with subsequent disposal by blood neutrophils are discussed. These intrinsic mechanisms of active drug extrusion at the BBB are potential therapeutic targets that could be used to modulate P-glycoprotein activity in the treatment of brain diseases and enhance drug delivery to the brain.

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Liposomes: Novel Drug Delivery Approach for Targeting Parkinson’s Disease

Current Pharmaceutical Design ◽

10.2174/1381612826666200128145124 ◽

2020 ◽

Vol 26 (37) ◽

pp. 4721-4737 ◽

Cited By ~ 4

Author(s):

Bhumika Kumar ◽

Mukesh Pandey ◽

Faheem H. Pottoo ◽

Faizana Fayaz ◽

Anjali Sharma ◽

...

Keyword(s):

Parkinson’S Disease ◽

Drug Delivery ◽

Parkinson's Disease ◽

Side Effects ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Brain Targeting ◽

Neural Cells ◽

Blood Brain ◽

The Brain

Parkinson’s disease is one of the most severe progressive neurodegenerative disorders, having a mortifying effect on the health of millions of people around the globe. The neural cells producing dopamine in the substantia nigra of the brain die out. This leads to symptoms like hypokinesia, rigidity, bradykinesia, and rest tremor. Parkinsonism cannot be cured, but the symptoms can be reduced with the intervention of medicinal drugs, surgical treatments, and physical therapies. Delivering drugs to the brain for treating Parkinson’s disease is very challenging. The blood-brain barrier acts as a highly selective semi-permeable barrier, which refrains the drug from reaching the brain. Conventional drug delivery systems used for Parkinson’s disease do not readily cross the blood barrier and further lead to several side-effects. Recent advancements in drug delivery technologies have facilitated drug delivery to the brain without flooding the bloodstream and by directly targeting the neurons. In the era of Nanotherapeutics, liposomes are an efficient drug delivery option for brain targeting. Liposomes facilitate the passage of drugs across the blood-brain barrier, enhances the efficacy of the drugs, and minimize the side effects related to it. The review aims at providing a broad updated view of the liposomes, which can be used for targeting Parkinson’s disease.

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Brain Drug Delivery: Overcoming the Blood-brain Barrier to Treat Tauopathies

Current Pharmaceutical Design ◽

10.2174/1381612826666200316130128 ◽

2020 ◽

Vol 26 (13) ◽

pp. 1448-1465 ◽

Cited By ~ 1

Author(s):

Jozef Hanes ◽

Eva Dobakova ◽

Petra Majerova

Keyword(s):

Drug Delivery ◽

Blood Brain Barrier ◽

Neurodegenerative Disorders ◽

Brain Barrier ◽

Neuronal Function ◽

Brain Drug Delivery ◽

Naturally Occurring ◽

Blood Brain ◽

Traditional Approaches ◽

The Brain

Tauopathies are neurodegenerative disorders characterized by the deposition of abnormal tau protein in the brain. The application of potentially effective therapeutics for their successful treatment is hampered by the presence of a naturally occurring brain protection layer called the blood-brain barrier (BBB). BBB represents one of the biggest challenges in the development of therapeutics for central nervous system (CNS) disorders, where sufficient BBB penetration is inevitable. BBB is a heavily restricting barrier regulating the movement of molecules, ions, and cells between the blood and the CNS to secure proper neuronal function and protect the CNS from dangerous substances and processes. Yet, these natural functions possessed by BBB represent a great hurdle for brain drug delivery. This review is concentrated on summarizing the available methods and approaches for effective therapeutics’ delivery through the BBB to treat neurodegenerative disorders with a focus on tauopathies. It describes the traditional approaches but also new nanotechnology strategies emerging with advanced medical techniques. Their limitations and benefits are discussed.

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P10.02 Combined methods of a micropump system and a chronic cranial window allows tumor observation with multi photon laser scanning microscopy under continuous treatment

Neuro-Oncology ◽

10.1093/neuonc/noab180.095 ◽

2021 ◽

Vol 23 (Supplement_2) ◽

pp. ii28-ii28

Author(s):

S Weil ◽

E Jung ◽

D Domínguez Azorín ◽

J Higgins ◽

J Reckless ◽

...

Keyword(s):

Drug Delivery ◽

Tumor Cells ◽

Blood Brain Barrier ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

New Drugs ◽

Brain Barrier ◽

Cranial Window ◽

Blood Brain ◽

The Brain

Abstract BACKGROUND Glioblastomas are notoriously therapy resistant tumors. As opposed to other tumor entities, no major advances in therapeutic success have been made in the past decades. This has been calling for a deeper biological understanding of the tumor, its growth and resistance patterns. We have been using a xenograft glioma model, where human glioblastoma cells are implanted under chronic cranial windows and studied longitudinally over many weeks and months using multi photon laser scanning microscopy (MPLSM). To test the effect of (new) drugs, a stable and direct delivery system avoiding the blood-brain-barrier has come into our interest. MATERIAL AND METHODS We implanted cranial windows and fluorescently labeled human glioblastoma stem-like cells into NMRI nude mice to follow up on the tumor development in our MPLSM model. After tumor establishment, an Alzet® micropump was implanted to directly deliver agents via a catheter system continuously over 28 days directly under the cranial window onto the brain surface. Using the MPLSM technique, the continuous delivery and infusion of drugs onto the brain and into the tumor was measured over many weeks in detail using MPLSM. RESULTS The establishment of the combined methods allowed reliable concurrent drug delivery over 28 days bypassing the blood-brain-barrier. Individual regions and tumor cells could be measured and followed up before, and after the beginning of the treatment, as well as after the end of the pump activity. Fluorescently labelled drugs were detectable in the MPLSM and its distribution into the brain parenchyma could be quantified. After the end of the micropump activity, further MPLSM measurements offer the possibility to observe long term effects of the applied drug on the tumor. CONCLUSION The combination of tumor observation in the MPSLM and concurrent continuous drug delivery is a feasible and reliable method for the investigation of (novel) anti-tumor agents, especially drugs that are not blood-brain-barrier penetrant. Morphological or even functional changes of individual tumor cells can be measured under and after treatment. These techniques can be used to test new drugs targeting the tumor, its tumor microtubes and tumor cells networks, and measure the effects longitudinally.

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Recent Advances in Targeted Drug Delivery Approaches using Lipidic and Polymeric Nanocarriers for the management of Alzheimer’s Disease

Current Pharmaceutical Design ◽

10.2174/1381612827666210927163258 ◽

2021 ◽

Vol 27 ◽

Author(s):

Dhara Lakdawala ◽

Md Abdur Rashid ◽

Farhan Jalees Ahmad

Keyword(s):

Alzheimer’S Disease ◽

Drug Delivery ◽

Alzheimer's Disease ◽

Blood Brain Barrier ◽

Targeted Drug Delivery ◽

Brain Barrier ◽

Polymeric Nanocarriers ◽

Blood Brain ◽

Targeted Drug ◽

The Brain

: Drug delivery to the brain has remained a significant challenge in treating neurodegenerative disorders such as Alzheimer's disease due to the presence of the blood-brain barrier, which primarily obstructs the access of drugs and biomolecules into the brain. Several methods to overcome the blood-brain barrier have been employed, such as chemical disruption, surgical intervention, focused ultrasound, intranasal delivery and using nanocarriers. Nanocarrier systems remain the method of choice and have shown promising results over the past decade to achieve better drug targeting. Polymeric nanocarriers and lipidic nanoparticles act as a carrier system providing better encapsulation of drugs, site-specific delivery, increased bioavailability and sustained release of drugs. The surface modifications and functionalization of these nanocarrier systems have greatly facilitated targeted drug delivery. The safety and efficacy of these nanocarrier systems have been ascertained by several in vitro and in vivo models. In the present review, we have elaborated on recent developments of nanoparticles as a drug delivery system for Alzheimer's disease, explicitly focusing on polymeric and lipidic nanoparticles.

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