scholarly journals Photomodulation of lymphatic delivery of liposomes to the brain bypassing the blood-brain barrier: new perspectives for glioma therapy

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Oxana Semyachkina-Glushkovskaya ◽  
Ivan Fedosov ◽  
Alexander Shirokov ◽  
Elena Vodovozova ◽  
Anna Alekseeva ◽  
...  

Abstract The blood-brain barrier (BBB) has a significant contribution to the protection of the central nervous system (CNS). However, it also limits the brain drug delivery and thereby complicates the treatment of CNS diseases. The development of safe methods for an effective delivery of medications and nanocarriers to the brain can be a revolutionary step in the overcoming this limitation. Here, we report the unique properties of the lymphatic system to deliver tracers and liposomes to the brain meninges, brain tissues, and glioma in rats. Using a quantum-dot-based 1267 nm laser (for photosensitizer-free generation of singlet oxygen), we clearly demonstrate photostimulation of lymphatic delivery of liposomes to glioma as well as lymphatic clearance of liposomes from the brain. These pilot findings open promising perspectives for photomodulation of lymphatic delivery of drugs and nanocarriers to the brain pathology bypassing the BBB. The lymphatic “smart” delivery of liposomes with antitumor drugs in the new brain tumor branches might be a breakthrough strategy for the therapy of gliomas.

Pharmaceutics ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 72 ◽  
Author(s):  
Gina P. Hoyos-Ceballos ◽  
Barbara Ruozi ◽  
Ilaria Ottonelli ◽  
Federica Da Ros ◽  
Maria Angela Vandelli ◽  
...  

The treatment of diseases that affect the central nervous system (CNS) represents a great research challenge due to the restriction imposed by the blood–brain barrier (BBB) to allow the passage of drugs into the brain. However, the use of modified nanomedicines engineered with different ligands that can be recognized by receptors expressed in the BBB offers a favorable alternative for this purpose. In this work, a BBB-penetrating peptide, angiopep-2 (Ang–2), was conjugated to poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles through pre- and post-formulation strategies. Then, their ability to cross the BBB was qualitatively assessed on an animal model. Proof-of-concept studies with fluorescent and confocal microscopy studies highlighted that the brain-targeted PLGA nanoparticles were able to cross the BBB and accumulated in neuronal cells, thus showing a promising brain drug delivery system.


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.


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.


1960 ◽  
Vol 198 (6) ◽  
pp. 1296-1298 ◽  
Author(s):  
Benedict Cassen ◽  
Richard Neff

Experimental evidence is obtained that, coincident with a state of not too severe concussion, the blood-brain barrier system becomes more permeable to phosphate ions. The permeability returns to normal when the animal recovers and shows normal activity. Arguments are presented in favor of the hypothesis that dysfunction of the central nervous system during concussion is related to a disturbed electrolyte balance in the fluids of the brain caused by a piezochemical disturbance of the blood-brain barrier membranes (presumably the astropods of the astrocytic cells).


Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1056
Author(s):  
Ekaterina Zinchenko ◽  
Maria Klimova ◽  
Aysel Mamedova ◽  
Ilana Agranovich ◽  
Inna Blokhina ◽  
...  

Alzheimer’s disease (AD) is an incurable pathology associated with progressive decline in memory and cognition. Phototherapy might be a new promising and alternative strategy for the effective treatment of AD, and has been actively discussed over two decades. However, the mechanisms of therapeutic photostimulation (PS) effects on subjects with AD remain poorly understood. The goal of this study was to determine the mechanisms of therapeutic PS effects in beta-amyloid (Aβ)-injected mice. The neurological severity score and the new object recognition tests demonstrate that PS 9 J/cm2 attenuates the memory and neurological deficit in mice with AD. The immunohistochemical assay revealed a decrease in the level of Aβ in the brain and an increase of Aβ in the deep cervical lymph nodes obtained from mice with AD after PS. Using the in vitro model of the blood-brain barrier (BBB), we show a PS-mediated decrease in transendothelial resistance and in the expression of tight junction proteins as well an increase in the BBB permeability to Aβ. These findings suggest that a PS-mediated BBB opening and the activation of the lymphatic clearance of Aβ from the brain might be a crucial mechanism underlying therapeutic effects of PS in mice with AD. These pioneering data open new strategies in the development of non-pharmacological methods for therapy of AD and contribute to a better understanding of the PS effects on the central nervous system.


2021 ◽  
Author(s):  
Sheng Yang ◽  
Yufei Huang ◽  
Yonghong Shi ◽  
Xuebing Bai ◽  
Ping Yang ◽  
...  

Tembusu Virus (TMUV) is an emerging and re-emerging zoonotic pathogen that adversely affects poultry industry in recent years. TMUV disease is characterized by nonsuppurative encephalitis in ducklings. The duckling infection model was established to study the mechanism of TMUV crossing the blood-brain barrier (BBB) into the central nervous system (CNS). Here, we showed that no obvious clinical symptoms and enhancement of BBB permeability occurred at the early stage of infection (3∼5 dpi). While simultaneously virus particles were observed by transmission electron microscopy in the brain, inducing the accumulation of inflammatory cytokines. Neurological symptoms and disruption of BBB appeared at the intermediate stage of infection (7∼9 dpi). It was confirmed that TMUV could survive and propagate in brain microvascular endothelial cells (BMECs), but did not affect the permeability of BBB in vivo and in vitro at an early date. In conclusion, TMUV enters the CNS then causes encephalitis, and finally destruct the BBB, which may be due to the direct effect of TMUV on BMECs and the subsequent response of “inflammatory storm”. IMPORTANCE The TMUV disease has caused huge losses to the poultry industry in Asia, which is potentially harmful to public health. Neurological symptoms and their sequelae are the main characters of this disease. However, the mechanism of how this virus enters the brain and causes encephalitis is unclear. In this study, we confirmed that the virus entered the CNS and then massively destroyed BBB and the BBB damage was closely associated with the subsequent outbreak of inflammation. TMUV may enter the CNS through the transcellular and “Trojan horse” pathways. These findings can fill the knowledge gap in the pathogenesis of TMUV-infected poultry and be benefit for the treatment of TMUV disease. What’s more, TMUV is a representative to study the infection of avian flavivirus. Therefore, our studies have significances both for understanding of the full scope of mechanisms of TMUV and other flavivirus infection, and conceivably, for therapeutics.


2020 ◽  
Vol 12 (564) ◽  
pp. eabe8119
Author(s):  
Raag Airan

Neural activity affects how the blood-brain barrier regulates influx and efflux of agents between the blood and the central nervous system.


1978 ◽  
Vol 235 (4) ◽  
pp. F331-F337 ◽  
Author(s):  
H. F. Cserr ◽  
B. J. Berman

Mechanisms and pathways of 125I and 35SCN efflux from the brain were investigated in anesthetized rats. Tracers were injected into the caudate nucleus through a guide cannula implanted 1 wk previously and concentrations of isotope in brain and cerebrospinal fluid (CSF) were determined at various times after injection. 125I clearance from the brain followed a single exponential curve. In control rats 36.2% of the 125I remained in the brain 30 min after injection and 60.4% in rats pretreated with perchlorate. Comparable values for 35SCN were 25.8% in control rats, 41.0% with perchlorate, and 39.7% with iodide loading. Estimates of 125I and 35SCN effluxes from the brain via the blood-brain barrier and CSF pathways suggest that greater than 95% of efflux crosses the blood-brain barrier. These results indicate that 1)iodide and thiocyanate are transported across the blood-brain barrier by a common mechanism, and 2) this efflux system is an important factor in the control of the distributions of iodide and thiocyanate in the central nervous system.


2020 ◽  
Vol 17 (5) ◽  
pp. 375-386 ◽  
Author(s):  
Behrang Shiri Varnamkhasti ◽  
Samira Jafari ◽  
Fereshteh Taghavi ◽  
Loghman Alaei ◽  
Zhila Izadi ◽  
...  

The passage of therapeutic molecules across the Blood-Brain Barrier (BBB) is a profound challenge for the management of the Central Nervous System (CNS)-related diseases. The ineffectual nature of traditional treatments for CNS disorders led to the abundant endeavor of researchers for the design the effective approaches in order to bypass BBB during recent decades. Cell-Penetrating Peptides (CPPs) were found to be one of the promising strategies to manage CNS disorders. CPPs are short peptide sequences with translocation capacity across the biomembrane. With special regard to their two key advantages like superior permeability as well as low cytotoxicity, these peptide sequences represent an appropriate solution to promote therapeutic/theranostic delivery into the CNS. This scenario highlights CPPs with specific emphasis on their applicability as a novel theranostic delivery system into the brain.


2021 ◽  
Vol 28 ◽  
Author(s):  
Yogesh Garg ◽  
Deepak N Kapoor ◽  
Abhishek Kumar Sharma ◽  
Amit Bhatia

Abstract: The transport of drugs to the central nervous system is the most challenging task for conventional drug delivery systems. Reduced permeability of drugs through the blood-brain barrier is a major hurdle in delivering drugs to the brain. Hence, various strategies for improving drug delivery through the blood-brain barrier are currently being explored. Novel drug delivery systems (NDDS) offer several advantages, including high chemical and biological stability, suitability for both hydrophobic and hydrophilic drugs, and can be administered through different routes. Furthermore, the conjugation of suitable ligands with these carriers tend to potentiate targeting to the endothelium of the brain and could facilitate the internalization of drugs through endocytosis. Further, the intranasal route has also shown potential, as a promising alternate route, for the delivery of drugs to the brain. This can deliver the drugs directly to the brain through the olfactory pathway. In recent years, several advancements have been made to target and overcome the barriers of the brain. This article deals with a detailed overview of the diverse strategies and delivery systems to overcome the barriers of the brain for effective delivery of drugs.


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