Blood–brain barrier shuttle peptides: an emerging paradigm for brain delivery

The blood-brain barrier and the blood-cerebrospinal fluid barrier are major obstacles in central nervous system (CNS) drug delivery, since they block most molecules from entering the brain. Alternative drug delivery routes like intraparenchymal or intrathecal are invasive methods with a remaining risk of infections. In contrast, nose-to-brain delivery is a minimally invasive drug administration pathway, which bypasses the blood-brain barrier as the drug is directed from the nasal cavity to the brain. In particular, the skull base located at the roof of the nasal cavity is in close vicinity to the CNS. This area is covered with olfactory mucosa. To design and tailor suitable formulations for nose-to-brain drug delivery, the architecture, structure and physico-chemical characteristics of the mucosa are important criteria. Hence, here we review the state-of-the-art knowledge about the characteristics of the nasal and, in particular, the olfactory mucosa needed for a rational design of intranasal formulations and dosage forms. Also, the information is suitable for the development of systemic or local intranasal drug delivery as well as for intranasal vaccinations.

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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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Characterization of the Blood–Brain Barrier Integrity and the Brain Transport of SN-38 in an Orthotopic Xenograft Rat Model of Diffuse Intrinsic Pontine Glioma

Pharmaceutics ◽

10.3390/pharmaceutics12050399 ◽

2020 ◽

Vol 12 (5) ◽

pp. 399 ◽

Cited By ~ 2

Author(s):

Catarina Chaves ◽

Xavier Declèves ◽

Meryam Taghi ◽

Marie-Claude Menet ◽

Joelle Lacombe ◽

...

Keyword(s):

Blood Brain Barrier ◽

Diffuse Intrinsic Pontine Glioma ◽

Brain Barrier ◽

Brain Delivery ◽

Pontine Glioma ◽

Anticancer Drug Delivery ◽

Blood Brain ◽

The Brain

The blood–brain barrier (BBB) hinders the brain delivery of many anticancer drugs. In pediatric patients, diffuse intrinsic pontine glioma (DIPG) represents the main cause of brain cancer mortality lacking effective drug therapy. Using sham and DIPG-bearing rats, we analyzed (1) the brain distribution of 3-kDa-Texas red-dextran (TRD) or [14C]-sucrose as measures of BBB integrity, and (2) the role of major ATP-binding cassette (ABC) transporters at the BBB on the efflux of the irinotecan metabolite [3H]-SN-38. The unaffected [14C]-sucrose or TRD distribution in the cerebrum, cerebellum, and brainstem regions in DIPG-bearing animals suggests an intact BBB. Targeted proteomics retrieved no change in P-glycoprotein (P-gp), BCRP, MRP1, and MRP4 levels in the analyzed regions of DIPG rats. In vitro, DIPG cells express BCRP but not P-gp, MRP1, or MRP4. Dual inhibition of P-gp/Bcrp, or Mrp showed a significant increase on SN-38 BBB transport: Cerebrum (8.3-fold and 3-fold, respectively), cerebellum (4.2-fold and 2.8-fold), and brainstem (2.6-fold and 2.2-fold). Elacridar increased [3H]-SN-38 brain delivery beyond a P-gp/Bcrp inhibitor effect alone, emphasizing the role of another unidentified transporter in BBB efflux of SN-38. These results confirm a well-preserved BBB in DIPG-bearing rats, along with functional ABC-transporter expression. The development of chemotherapeutic strategies to circumvent ABC-mediated BBB efflux are needed to improve anticancer drug delivery against DIPG.

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Peptide decorated glycolipid nanomicelles for drug delivery across the blood–brain barrier (BBB)

Biomaterials Science ◽

10.1039/c9bm00955h ◽

2019 ◽

Vol 7 (10) ◽

pp. 4017-4021 ◽

Cited By ~ 4

Author(s):

S. Meenu Vasudevan ◽

N. Ashwanikumar ◽

G. S. Vinod Kumar

Keyword(s):

Drug Delivery ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Brain Delivery ◽

Blood Brain

Schematic summary of the development of peptide decorated glycolipid nanomicelles for brain delivery by crossing Blood Brain Barrier (BBB).

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Nose-to-Brain Delivery

Pharmaceutics ◽

10.3390/pharmaceutics12020138 ◽

2020 ◽

Vol 12 (2) ◽

pp. 138 ◽

Cited By ~ 2

Author(s):

Paolo Giunchedi ◽

Elisabetta Gavini ◽

Maria Cristina Bonferoni

Keyword(s):

Side Effects ◽

Blood Brain Barrier ◽

Neurological Diseases ◽

Systemic Administration ◽

Brain Barrier ◽

Brain Delivery ◽

Special Issue ◽

Drug Bioavailability ◽

Blood Brain ◽

The Brain

Nose-to-brain delivery represents a big challenge. In fact there is a large number of neurological diseases that require therapies in which the drug must reach the brain, avoiding the difficulties due to the blood–brain barrier (BBB) and the problems connected with systemic administration, such as drug bioavailability and side-effects. For these reasons the development of nasal formulations able to deliver the drug directly into the brain is of increasing importance. This Editorial regards the contributions present in the Special Issue “Nose-to-Brain Delivery”.

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