Mechanisms of Photostimulation of Brain's Waste Disposal System: The Role of Singlet Oxygen.

There is strong evidence that augmentation of the brain's waste disposal system via stimulation of the meningeal lymphatics might be a promising therapeutic target for preventing neurological diseases. In our previous studies, we demonstrated activation of the brain's waste disposal system using transcranial photostimulation (PS) with a laser 1267 nm, which stimulates the direct generation of singlet oxygen in the brain tissues. Here we investigate the mechanisms underlying this phenomenon. Our results clearly demonstrate that PS-mediated stimulation of the brain's waste disposal system is accompanied by activation of lymphatic contractility associated with subsequent intracellular production of the reactive oxygen species and the nitric oxide underlying lymphatic relaxation. Thus, PS stimulates the brain's waste disposal system by influencing the mechanisms of regulation of lymphatic pumping.

Phototherapy of Alzheimer's Disease: Photostimulation of Brain Lymphatics during Sleep: A Systematic Review.

The global number of people with Alzheimer's disease (AD) doubles every 5 years. It has been established that unless an effective treatment for AD is found, the incidence of AD will triple by 2060. However, pharmacological therapies for AD have failed to show effectiveness and safety. Therefore, the search for alternative methods for treating AD is an urgent problem in medicine. The lymphatic drainage and removal system of the brain (LDRSB) plays an important role in resistance to the progression of AD. The development of methods for augmentation of the LDRSB functions may contribute to progress in AD therapy. Photobiomodulation (PBM) is considered to be a non-pharmacological and safe approach for AD therapy. Here, we highlight the most recent and relevant studies of PBM for AD. We focus on emerging evidence that indicates the potential benefits of PBM during sleep for modulation of natural activation of the LDRSB at nighttime, providing effective removal of metabolites, including amyloid-ß, from the brain, leading to reduced progression of AD. Our review creates a new niche in the therapy of brain diseases during sleep and sheds light on the development of smart sleep technologies for neurodegenerative diseases.

Brain Waste Removal System and Sleep: Photobiomodulation as an Innovative Strategy for Night Therapy of Brain Diseases.

Emerging evidence suggests that an important function of the sleeping brain is the removal of wastes and toxins from the central nervous system (CNS) due to the activation of the brain waste removal system (BWRS). The meningeal lymphatic vessels (MLVs) are an important part of the BWRS. A decrease in MLV function is associated with Alzheimer's and Parkinson's diseases, intracranial hemorrhages, brain tumors and trauma. Since the BWRS is activated during sleep, a new idea is now being actively discussed in the scientific community: night stimulation of the BWRS might be an innovative and promising strategy for neurorehabilitation medicine. This review highlights new trends in photobiomodulation of the BWRS/MLVs during deep sleep as a breakthrough technology for the effective removal of wastes and unnecessary compounds from the brain in order to increase the neuroprotection of the CNS as well as to prevent or delay various brain diseases.

Transcranial Photosensitizer-Free Laser Treatment of Glioblastoma in Rat Brain.

Over sixty years, laser technologies have undergone a technological revolution and become one of the main tools in biomedicine, particularly in neuroscience, neurodegenerative diseases and brain tumors. Glioblastoma is the most lethal form of brain cancer, with very limited treatment options and a poor prognosis. In this study on rats, we demonstrate that glioblastoma (GBM) growth can be suppressed by photosensitizer-free laser treatment (PS-free-LT) using a quantum-dot-based 1267 nm laser diode. This wavelength, highly absorbed by oxygen, is capable of turning triplet oxygen to singlet form. Applying 1267 nm laser irradiation for a 4 week course with a total dose of 12.7 kJ/cm2 firmly suppresses GBM growth and increases survival rate from 34% to 64%, presumably via LT-activated apoptosis, inhibition of the proliferation of tumor cells, a reduction in intracranial pressure and stimulation of the lymphatic drainage and clearing functions. PS-free-LT is a promising breakthrough technology in non- or minimally invasive therapy for superficial GBMs in infants as well as in adult patients with high photosensitivity or an allergic reaction to PSs.

Photomodulation of Lymphatic Delivery of Bevacizumab to the Brain: The Role of Singlet Oxygen.

The blood-brain barrier (BBB) poses a significant challenge for drug delivery to the brain. Therefore, the development of safe methods for an effective delivery of medications to the brain can be a revolutionary step in overcoming this limitation. Using a quantum-dot-based 1267 nm laser (photosensitiser-free generation of singlet oxygen), we clearly show the photostimulation of lymphatic delivery of bevacizumab (BMZ) to the brain tissues and the meninges. These pilot findings open promising perspectives for photomodulation of a lymphatic brain drug delivery bypassing the BBB, and potentially enabling a breakthrough strategy in therapy of glioma using BMZ and other chemotherapy drugs.

Photodynamic opening of the blood-brain barrier affects meningeal lymphatics and the brain's drainage in healthy male mice.

Here, we present the new vascular effects of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA). PDT with 5-ALA induces a leakage of both the meningeal and cerebral blood vessels. The extravasation of photo-excited 5-ALA from the leaky blood vessels into the meninges causes photo-damage of the meningeal lymphatics (MLVs) leading to a dramatic reducing the MLV network and brain's drainage. The PDT-induced impairment of lymphatic regulation of brain's drainage can lead to excessive accumulation of fluids in brain tissues, which is important to consider in the PDT therapy for brain diseases as s possible side effect of PDT with 5-ALA.

Photobiomodulation under Electroencephalographic Controls of Sleep for Stimulation of Lymphatic Removal of Toxins from Mouse Brain.

The meningeal lymphatic vessels (MLVs) play an important role in the removal of toxins from the brain. The development of innovative technologies for the stimulation of MLV functions is a promising direction in the progress of the treatment of various brain diseases associated with MLV abnormalities, including Alzheimer's and Parkinson's diseases, brain tumors, traumatic brain injuries, and intracranial hemorrhages. Sleep is a natural state when the brain's drainage processes are most active. Therefore, stimulation of the brain's drainage and MLVs during sleep may have the most pronounced therapeutic effects. However, such commercial technologies do not currently exist. This study presents a new portable technology of transcranial photobiomodulation (tPBM) under electroencephalographic (EEG) control of sleep designed to photo-stimulate removal of toxins (e.g., soluble amyloid beta (Aß)) from the brain of aged BALB/c mice with the ability to compare the therapeutic effectiveness of different optical resources. The technology can be used in the natural condition of a home cage without anesthesia, maintaining the motor activity of mice. These data open up new prospects for developing non-invasive and clinically promising photo-technologies for the correction of age-related changes in the MLV functions and brain's drainage processes and for effectively cleansing brain tissues from metabolites and toxins. This technology is intended both for preclinical studies of the functions of the sleeping brain and for developing clinically relevant treatments for sleep-related brain diseases.

Technology of the photobiostimulation of the brain's drainage system during sleep for improvement of learning and memory in male mice.

In this study on healthy male mice using confocal imaging of dye spreading in the brain and its further accumulation in the peripheral lymphatics, we demonstrate stronger effects of photobiomodulation (PBM) on the brain's drainage system in sleeping vs. awake animals. Using the Pavlovian instrumental transfer probe and the 2-objects-location test, we found that the 10-day course of PBM during sleep vs. wakefulness promotes improved learning and spatial memory in mice. For the first time, we present the technology for PBM under electroencephalographic (EEG) control that incorporates modern state of the art facilities of optoelectronics and biopotential detection and that can be built of relatively cheap and commercially available components. These findings open a new niche in the development of smart technologies for phototherapy of brain diseases during sleep.

Different Effects of Phototherapy for Rat Glioma during Sleep and Wakefulness.

There is an association between sleep quality and glioma-specific outcomes, including survival. The critical role of sleep in survival among subjects with glioma may be due to sleep-induced activation of brain drainage (BD), that is dramatically suppressed in subjects with glioma. Emerging evidence demonstrates that photobiomodulation (PBM) is an effective technology for both the stimulation of BD and as an add-on therapy for glioma. Emerging evidence suggests that PBM during sleep stimulates BD more strongly than when awake. In this study on male Wistar rats, we clearly demonstrate that the PBM course during sleep vs. when awake more effectively suppresses glioma growth and increases survival compared with the control. The study of the mechanisms of this phenomenon revealed stronger effects of the PBM course in sleeping vs. awake rats on the stimulation of BD and an immune response against glioma, including an increase in the number of CD8+ in glioma cells, activation of apoptosis, and blockage of the proliferation of glioma cells. Our new technology for sleep-phototherapy opens a new strategy to improve the quality of medical care for patients with brain cancer, using promising smart-sleep and non-invasive approaches of glioma treatment.

Low-Level Laser Treatment Induces the Blood-Brain Barrier Opening and the Brain Drainage System Activation: Delivery of Liposomes into Mouse Glioblastoma.

The progress in brain diseases treatment is limited by the blood-brain barrier (BBB), which prevents delivery of the vast majority of drugs from the blood into the brain. In this study, we discover unknown phenomenon of opening of the BBBB (BBBO) by low-level laser treatment (LLLT, 1268 nm) in the mouse cortex. LLLT-BBBO is accompanied by activation of the brain drainage system contributing effective delivery of liposomes into glioblastoma (GBM). The LLLT induces the generation of singlet oxygen without photosensitizers (PSs) in the blood endothelial cells and astrocytes, which can be a trigger mechanism of BBBO. LLLT-BBBO causes activation of the ABC-transport system with a temporal decrease in the expression of tight junction proteins. The BBB recovery is accompanied by activation of neuronal metabolic activity and stabilization of the BBB permeability. LLLT-BBBO can be used as a new opportunity of interstitial PS-free photodynamic therapy (PDT) for modulation of brain tumor immunity and improvement of immuno-therapy for GBM in infants in whom PDT with PSs, radio- and chemotherapy are strongly limited, as well as in adults with a high allergic reaction to PSs.

Photostimulation of brain lymphatics in male newborn and adult rodents for therapy of intraventricular hemorrhage.

Intraventricular hemorrhage is one of the most fatal forms of brain injury that is a common complication of premature infants. However, the therapy of this type of hemorrhage is limited, and new strategies are needed to reduce hematoma expansion. Here we show that the meningeal lymphatics is a pathway to remove red blood cells from the brain's ventricular system of male human, adult and newborn rodents and is a target for non-invasive transcranial near infrared photobiomodulation. Our results uncover the clinical significance of phototherapy of intraventricular hemorrhage in 4-day old male rat pups that have the brain similar to a preterm human brain. The course of phototherapy in newborn rats provides fast recovery after intraventricular hemorrhage due to photo-improvements of lymphatic drainage and clearing functions. These findings shed light on the mechanisms of phototherapy of intraventricular hemorrhage that can be a clinically relevant technology for treatment of neonatal intracerebral bleedings.

Machine Learning Technology for EEG-Forecast of the Blood-Brain Barrier Leakage and the Activation of the Brain's Drainage System during Isoflurane Anesthesia.

Anesthesia enables the painless performance of complex surgical procedures. However, the effects of anesthesia on the brain may not be limited only by its duration. Also, anesthetic agents may cause long-lasting changes in the brain. There is growing evidence that anesthesia can disrupt the integrity of the blood-brain barrier (BBB), leading to neuroinflammation and neurotoxicity. However, there are no widely used methods for real-time BBB monitoring during surgery. The development of technologies for an express diagnosis of the opening of the BBB (OBBB) is a challenge for reducing post-surgical/anesthesia consequences. In this study on male rats, we demonstrate a successful application of machine learning technology, such as artificial neural networks (ANNs), to recognize the OBBB induced by isoflurane, which is widely used in surgery. The ANNs were trained on our previously presented data obtained on the sound-induced OBBB with an 85% testing accuracy. Using an optical and nonlinear analysis of the OBBB, we found that 1% isoflurane does not induce any changes in the BBB, while 4% isoflurane caused significant BBB leakage in all tested rats. Both 1% and 4% isoflurane stimulate the brain's drainage system (BDS) in a dose-related manner. We show that ANNs can recognize the OBBB induced by 4% isoflurane in 57% of rats and BDS activation induced by 1% isoflurane in 81% of rats. These results open new perspectives for the development of clinically significant bedside technologies for EEG-monitoring of OBBB and BDS.

Photodynamic Opening of the Blood-Brain Barrier and the Meningeal Lymphatic System: The New Niche in Immunotherapy for Brain Tumors.

Photodynamic therapy (PDT) is a promising add-on therapy to the current standard of care for patients with glioblastoma (GBM). The traditional explanation of the anti-cancer PDT effects involves the PDT-induced generation of a singlet oxygen in the GBM cells, which causes tumor cell death and microvasculature collapse. Recently, new vascular mechanisms of PDT associated with opening of the blood-brain barrier (OBBB) and the activation of functions of the meningeal lymphatic vessels have been discovered. In this review, we highlight the emerging trends and future promises of immunotherapy for brain tumors and discuss PDT-OBBB as a new niche and an important informative platform for the development of innovative pharmacological strategies for the modulation of brain tumor immunity and the improvement of immunotherapy for GBM.

GB20 Pharmacopuncture As a Potential Method for Brain Drug Delivery via the Perivascular Spaces.

Background: The development of new methods of drug brain delivery is a crucial step for the effective therapy of the brain diseases. Pharma- and acupuncture are the forms of alternative therapy of the brain pathology, including an increase in the permeability of blood-brain barrier. However, the mechanisms of pharma- and acupuncture-mediated effects on the brain physiology remain not fully understood. Results: This pilot study on healthy mice clearly demonstrates the Evans Blue spreading in the mouse head and in the brain via the perivascular spaces (PVSs) of the trigeminal structure and the cribriform plate after the dye injection into the Feng Chi point (Galbladder 20, GB20). Conclusion: These results suggest that pharmacopuncture at GB20 can be a perspective method for brain drug delivery via PVSs.

Music improves the therapeutic effects of bevacizumab in rats with glioblastoma: Modulation of drug distribution to the brain.

Background: The development of new methods for modulation of drug distribution across to the brain is a crucial step in the effective therapies for glioblastoma (GBM). In our previous work, we discovered the phenomenon of music-induced opening of the blood-brain barrier (OBBB) in healthy rodents. In this pilot study on rats, we clearly demonstrate that music-induced BBB opening improves the therapeutic effects of bevacizumab (BZM) in rats with GBM via increasing BZM distribution to the brain along the cerebral vessels. Methods: The experiments were performed on Wistar male rats (200-250 g, n=161) using transfected C6-TagRFP cell line and the loud rock music for OBBB. The OBBB was assessed by spectrofluorometric assay of Evans Blue (EB) extravasation and confocal imaging of fluorescent BZM (fBZM) delivery into the brain. Additionally, distribution of fBZM and Omniscan in the brain was studied using fluorescent and magnetic resonance imaging (MRI), respectively. To analyze the therapeutic effects of BZM on the GBM growth in rats without and with OBBB, the GBM volume (MRI scans), as well as immunohistochemistry assay of proliferation (Ki67 marker) and apoptosis (Bax marker) in the GBM cells were studied. The Mann-Whitney-Wilcoxon test was used for all analysis, the significance level was p < 0.05, n=7 in each group. Results: Our finding clearly demonstrates that music-induced OBBB increases the delivery of EB into the brain tissues and the extravasation of BZM into the brain around the cerebral vessels of rats with GBM. Music significantly increases distribution of tracers (fBZM and Omniscan) in the rat brain through the pathways of brain drainage system (perivascular and lymphatic), which are an important route of drug delivery into the brain. The music-induced OBBB improves the suppressive effects of BZM on the GBM volume and the cellular mechanisms of tumor progression that was accompanied by higher survival among rats in the GBM+BZM+Music group vs. other groups. Conclusion: We hypothesized that music improves the therapeutic effects of BZM via OBBB in the normal cerebral vessels and lymphatic drainage of the brain tissues. This contributes better distribution of BZM in the brain fluids and among the normal cerebral vessels, which are used by GBM for invasion and co-opt existing vessels as a satellite tumor form. These results open the new perspectives for an improvement of therapeutic effects of BZM via the music-induced OBBB for BZM in the normal cerebral vessels, which are used by GBM for migration and progression.

Intranasal Delivery of Liposomes to Glioblastoma by Photostimulation of the Lymphatic System.

The blood-brain barrier (BBB) limits the delivery of majority of cancer drugs and thereby complicates brain tumor treatment. The nasal-brain-lymphatic system is discussed as a pathway for brain drug delivery overcoming the BBB. However, in most cases, this method is not sufficient to achieve a therapeutic effect due to brain drug delivery in a short distance. Therefore, it is necessary to develop technologies to overcome the obstacles facing nose-to-brain delivery of promising pharmaceuticals. In this study, we clearly demonstrate intranasal delivery of liposomes to the mouse brain reaching glioblastoma (GBM). In the experiments with ablation of the meningeal lymphatic network, we report an important role of meningeal pathway for intranasal delivery of liposomes to the brain. Our data revealed that GBM is characterized by a dramatic reduction of intranasal delivery of liposomes to the brain that was significantly improved by near-infrared (1267 nm) photostimulation of the lymphatic vessels in the area of the cribriform plate and the meninges. These results open new perspectives for non-invasive improvement of efficiency of intranasal delivery of cancer drugs to the brain tissues using nanocarriers and near-infrared laser-based therapeutic devices, which are commercially available and widely used in clinical practice.

Night Photostimulation of Clearance of Beta-Amyloid from Mouse Brain: New Strategies in Preventing Alzheimer's Disease.

The deposition of amyloid-ß (Aß) in the brain is a risk factor for Alzheimer's disease (AD). Therefore, new strategies for the stimulation of Aß clearance from the brain can be useful in preventing AD. Transcranial photostimulation (PS) is considered a promising method for AD therapy. In our previous studies, we clearly demonstrated the PS-mediated stimulation of lymphatic clearing functions, including Aß removal from the brain. There is increasing evidence that sleep plays an important role in Aß clearance. Here, we tested our hypothesis that PS at night can stimulate Aß clearance from the brain more effectively than PS during the day. Our results on healthy mice show that Aß clearance from the brain occurs faster at night than during wakefulness. The PS course at night improves memory and reduces Aß accumulation in the brain of AD mice more effectively than the PS course during the day. Our results suggest that night PS is a more promising candidate as an effective method in preventing AD than daytime PS. These data are an important informative platform for the development of new noninvasive and nonpharmacological technologies for AD therapy as well as for preventing Aß accumulation in the brain of people with disorder of Aß metabolism, sleep deficit, elderly age, and jet lag.

Photobiomodulation of lymphatic drainage and clearance: perspective strategy for augmentation of meningeal lymphatic functions.

There is a hypothesis that augmentation of the drainage and clearing function of the meningeal lymphatic vessels (MLVs) might be a promising therapeutic target for preventing neurological diseases. Here we investigate mechanisms of photobiomodulation (PBM, 1267 nm) of lymphatic drainage and clearance. Our results obtained at optical coherence tomography (OCT) give strong evidence that low PBM doses (5 and 10 J/cm2) stimulate drainage function of the lymphatic vessels via vasodilation (OCT data on the mesenteric lymphatics) and stimulation of lymphatic clearance (OCT data on clearance of gold nanorods from the brain) that was supported by confocal imaging of clearance of FITC-dextran from the cortex via MLVs. We assume that PBM-mediated relaxation of the lymphatic vessels can be possible mechanisms underlying increasing the permeability of the lymphatic endothelium that allows molecules transported by the lymphatic vessels and explain PBM stimulation of lymphatic drainage and clearance. These findings open new strategies for the stimulation of MLVs functions and non-pharmacological therapy of brain diseases.

Phenomenon of atypical vascular effects of epinephrine and an increase of photodynamic response by nitroglycerin in rats with colon adenocarcinoma: adrenergic and nitrergic mechanisms and novel applied aspects.

Using an original model of stress-induced colon adenocarcinoma, we uncover atypical vasorelaxation effects of a mucosa injection of epinephrine assessed by laser speckle contrast imaging and a significant increase of fluorescent intensity of 5-ALA/PpIX from malignant colon tissues by a mucosa injection of nitroglycerine. We clearly demonstrate a high activity of adrenergic and nitrergic mechanisms underlying this phenomenon and discuss their application in improving of optical approaches for effective diagnosis of gastrointestinal cancer.

Pilot study of transcranial photobiomodulation of lymphatic clearance of beta-amyloid from the mouse brain: breakthrough strategies for non-pharmacologic therapy of Alzheimer's disease.

In this pilot study, we analyzed effects of transcranial photobiomodulation (tPBM, 1267 nm, 32 J/cm2) on clearance of beta-amyloid (Aß) from the mouse brain. The immunohistochemical and confocal data clearly demonstrate the significant reduction of deposition of Aß plaques in mice after tPBM vs. untreated animals. The behavior tests showed that tPBM improved the cognitive, memory and neurological status of mice with Alzheimer's disease (AD). Using of our original method based on optical coherence tomography (OCT) analysis of clearance of gold nanorods (GNRs) from the brain, we proposed possible mechanism underlying tPBM-stimulating effects on clearance of Aß via the lymphatic system of the brain and the neck. These results open breakthrough strategies for a non-pharmacological therapy of Alzheimer's disease and clearly demonstrate that tPBM might be a promising therapeutic target for preventing or delaying Alzheimer's disease.