scholarly journals Blood–brain barrier and laser technology for drug brain delivery

2017 ◽  
Vol 10 (05) ◽  
pp. 1730011 ◽  
Author(s):  
Oxana V. Semyachkina-Glushkovskaya ◽  
Arkady S. Abdurashitov ◽  
Elena I. Saranceva ◽  
Eketerina G. Borisova ◽  
Alexander A. Shirokov ◽  
...  

Here, we discuss an important problem in medicine as development of effective strategies for brain drug delivery. This problem is related to the blood–brain barrier (BBB), which is a “customs” controlling the entrance of different molecules from blood into the brain protecting the normal function of central nervous system (CNS). We show three interfaces of anatomical side of BBB and two functional types of BBB — physical and transporter barriers. Although this protective mechanism is essential for health of CNS, it also creates a hindrance to the entry of drugs into the brain. The BBB was discovered over 100 years ago but till now, there is no effective methods for brain drug delivery. There are more than 70 approaches for overcoming BBB including physical, chemical and biological techniques but all of these tools have limitation to be widely used in clinical practice due to invasiveness, challenge in performing, very costly or limitation of drug concentration.Photodynamic therapy (PDT) is usual clinical method of surgical navigation for the resection of brain tumor and anti-cancer therapy. Nowadays, the application of PDT is considered as a potential promising tool for brain drug delivery via opening of BBB. Here, we show the first successful experimental results in this field discussing the adventures and disadvantages of PDT-related BBB disruption as well as alternatives to overcome these limitations and possible mechanisms with new pathways for brain clearance via glymphatic and lymphatic systems.

2020 ◽  
Vol 26 (13) ◽  
pp. 1448-1465 ◽  
Author(s):  
Jozef Hanes ◽  
Eva Dobakova ◽  
Petra Majerova

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.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2049
Author(s):  
David Lee ◽  
Tamara Minko

Treatment of neurodegenerative diseases or other central nervous system (CNS) disorders has always been a significant challenge. The nature of the blood-brain barrier (BBB) limits the penetration of therapeutic molecules to the brain after oral or parenteral administration, which, in combination with hepatic metabolism and drug elimination and inactivation during its journey in the systemic circulation, decreases the efficacy of the treatment, requires high drug doses and often induces adverse side effects. Nose-to-brain drug delivery allows the direct transport of therapeutic molecules by bypassing the BBB and increases drug concentration in the brain. The present review describes mechanisms of nose-to-brain drug delivery and discusses recent advances in this area with especial emphasis on nanotechnology-based approaches.


2020 ◽  
Vol 15 (11) ◽  
pp. 1934578X2095365
Author(s):  
Hiroki Hamada ◽  
Takahiro Nakayama ◽  
Kei Shimoda ◽  
Nobuyasu Matsuura ◽  
Hatsuyuki Hamada ◽  
...  

In order to expand our drug delivery technique by glycosylation of chemical into brain delivery, it was demonstrated that oligosaccharide and monosaccharide modifications of curcumin enhanced its crossing ability of the blood-brain barrier (BBB) in mice. The brain sample prepared by glycosidase-catalyzed hydrolysis of brain tissue homogenates of mice, to which curcumin gluco-oligosaccharides were intraperitoneally injected, contained curcumin at 116 ng/1 g of tissue of brain, indicating that curcumin modified with gluco-oligosaccharides residues can smoothly cross the BBB in mouse brain. The brain samples of mice, which were treated with curcumin monosaccharide or curcumin itself, contained curcumin at 18 ng and 0 ng per 1 g of tissue of brain, respectively. On the other hand, after the administration of curcumin gluco-oligosaccharides to C57BL mouse with a large tumor for 5 days, the tumor disappeared.


Author(s):  
Elisa E. Konofagou

Current treatments of neurological and neurodegenerative diseases are limited due to the lack of a truly non-invasive, transient, and regionally selective brain drug delivery method. The brain is particularly difficult to deliver drugs to because of the blood-brain barrier (BBB). The impermeability of the BBB is due to the tight junctions connecting adjacent endothelial cells and highly regulatory transport systems of the endothelial cell membranes. The main function of the BBB is ion and volume regulation to ensure conditions necessary for proper synaptic and axonal signaling. However, the same permeability properties that keep the brain healthy also constitute the cause of the tremendous obstacles posed in its pharmacological treatment. The BBB prevents most neurologically active drugs from entering the brain and, as a result, has been isolated as the rate-limiting factor in brain drug delivery. Until a solution to the trans-BBB delivery problem is found, treatments of neurological diseases will remain impeded. Over the past decade, methods that combine Focused Ultrasound (FUS) and microbubbles have been shown to offer the unique capability of noninvasively, locally and transiently opening the BBB so as to treat central nervous system (CNS) diseases. Four of the main challenges that lie ahead are to: 1) assess its safety profile, 2) unveil the mechanism by which the BBB opens and closes, 3) control and predict the opened BBB properties and duration of the opening and 4) assess its premise in brain drug delivery. All these challenges will be discussed, findings in both small (mice) and large (non-human primates) animals will be shown and finally the case for this technique for clinical applications will be made.


2020 ◽  
Vol 26 (37) ◽  
pp. 4721-4737 ◽  
Author(s):  
Bhumika Kumar ◽  
Mukesh Pandey ◽  
Faheem H. Pottoo ◽  
Faizana Fayaz ◽  
Anjali Sharma ◽  
...  

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.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii28-ii28
Author(s):  
S Weil ◽  
E Jung ◽  
D Domínguez Azorín ◽  
J Higgins ◽  
J Reckless ◽  
...  

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.


2021 ◽  
Vol 27 ◽  
Author(s):  
Dhara Lakdawala ◽  
Md Abdur Rashid ◽  
Farhan Jalees Ahmad

: 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.


2006 ◽  
Vol 6 (9) ◽  
pp. 2712-2735 ◽  
Author(s):  
J. M. Koziara ◽  
P. R. Lockman ◽  
D. D. Allen ◽  
R. J. Mumper

The present report encompasses a thorough review of drug delivery to the brain with a particular focus on using drug carriers such as liposomes and nanoparticles. Challenges in brain drug delivery arise from the presence of one of the strictest barriers in vivo—the blood-brain barrier (BBB). This barrier exists at the level of endothelial cells of brain vasculature and its role is to maintain brain homeostasis. To better understand the principles of brain drug delivery, relevant knowledge of the blood-brain barrier anatomy and physiology is briefly reviewed. Several approaches to overcome the BBB have been reviewed including the use of carrier systems. In addition, strategies to enhance brain drug delivery by specific brain targeting are discussed.


2020 ◽  
Vol 13 (10) ◽  
pp. 279
Author(s):  
Dina Sikpa ◽  
Lisa Whittingstall ◽  
Martin Savard ◽  
Réjean Lebel ◽  
Jérôme Côté ◽  
...  

The blood–brain barrier (BBB) is a major obstacle to the development of effective diagnostics and therapeutics for brain cancers and other central nervous system diseases. Peptide agonist analogs of kinin B1 and B2 receptors, acting as BBB permeabilizers, have been utilized to overcome this barrier. The purpose of the study was to provide new insights for the potential utility of kinin analogs as brain drug delivery adjuvants. In vivo imaging studies were conducted in various animal models (primary/secondary brain cancers, late radiation-induced brain injury) to quantify BBB permeability in response to kinin agonist administrations. Results showed that kinin B1 (B1R) and B2 receptors (B2R) agonists increase the BBB penetration of chemotherapeutic doxorubicin to glioma sites, with additive effects when applied in combination. B2R agonist also enabled extravasation of high-molecular-weight fluorescent dextrans (155 kDa and 2 MDa) in brains of normal mice. Moreover, a systemic single dose of B2R agonist did not increase the incidence of metastatic brain tumors originating from circulating breast cancer cells. Lastly, B2R agonist promoted the selective delivery of co-injected diagnostic MRI agent Magnevist in irradiated brain areas, depicting increased vascular B2R expression. Altogether, our findings suggest additional evidence for using kinin analogs to facilitate specific access of drugs to the brain.


RSC Advances ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 6160-6171 ◽  
Author(s):  
Rui-Chao Liang ◽  
Fang Fang ◽  
Yan-Chao Wang ◽  
Ni-Jia Song ◽  
Jie-Hua Li ◽  
...  

Gemini quaternary ammonium (GQA) incorporated biodegradable multiblock polyurethane (BMPUs) micelles could transport drug across blood–brain barrier and improve brain drug accumulation.


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