scholarly journals New Approaches in Nanomedicine for Ischemic Stroke

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 757
Author(s):  
Clara Correa-Paz ◽  
Andrés da Silva-Candal ◽  
Ester Polo ◽  
Jérôme Parcq ◽  
Denis Vivien ◽  
...  

Ischemic stroke, caused by the interruption of blood flow to the brain and subsequent neuronal death, represents one of the main causes of disability in developed countries. Therapeutic methods such as recanalization approaches, neuroprotective drugs, or recovery strategies have been widely developed to improve the patient’s outcome; however, important limitations such as a narrow therapeutic window, the ability to reach brain targets, or drug side effects constitute some of the main aspects that limit the clinical applicability of the current treatments. Nanotechnology has emerged as a promising tool to overcome many of these drug limitations and improve the efficacy of treatments for neurological diseases such as stroke. The use of nanoparticles as a contrast agent or as drug carriers to a specific target are some of the most common approaches developed in nanomedicine for stroke. Throughout this review, we have summarized our experience of using nanotechnology tools for the study of stroke and the search for novel therapies.

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Alessandro Galgani ◽  
Francesco Lombardo ◽  
Daniele Della Latta ◽  
Nicola Martini ◽  
Ubaldo Bonuccelli ◽  
...  

Abstract Purpose of Review Locus coeruleus (LC) is the main noradrenergic nucleus of the brain, and its degeneration is considered to be key in the pathogenesis of neurodegenerative diseases. In the last 15 years,MRI has been used to assess LC in vivo, both in healthy subjects and in patients suffering from neurological disorders. In this review, we summarize the main findings of LC-MRI studies, interpreting them in light of preclinical and histopathological data, and discussing its potential role as diagnostic and experimental tool. Recent findings LC-MRI findings were largely in agreement with neuropathological evidences; LC signal showed to be not significantly affected during normal aging and to correlate with cognitive performances. On the contrary, a marked reduction of LC signal was observed in patients suffering from neurodegenerative disorders, with specific features. Summary LC-MRI is a promising tool, which may be used in the future to explore LC pathophysiology as well as an early biomarker for degenerative diseases.


2018 ◽  
Vol 42 (21) ◽  
pp. 17359-17370 ◽  
Author(s):  
Yutao Li ◽  
Yanxin Dang ◽  
Dandan Han ◽  
Yong Tan ◽  
Xin Liu ◽  
...  

Effective intervention against ischemic stroke requires delivery of potent neuroprotective drugs to the brain.


Author(s):  
Ramón Iglesias-Rey ◽  
Andres da Silva-Candal ◽  
Manuel Rodríguez-Yáñez ◽  
Ana Estany-Gestal ◽  
Uxía Regueiro ◽  
...  

AbstractThe National Institutes of Health Stroke Scale (NIHSS) is commonly used to evaluate stroke neurological deficits and to predict the patient’s outcome. Neurological instability (NI), defined as the variation of the NIHSS in the first 48 h, is a simple clinical metric that reflects dynamic changes in the area of the brain affected by the ischemia. We hypothesize that NI may represent areas of cerebral instability known as penumbra, which could expand or reduce brain injury and its associated neurological sequels. In this work, our aim was to analyze the association of NI with the functional outcome at 3 months and to study clinical biomarkers associated to NI as surrogate biomarkers of ischemic and inflammatory penumbrae in ischemic stroke (IS) patients. We included 663 IS patients in a retrospective observational study. Neutral NI was defined as a variation in the NI scale between − 5 and 5% (37.1%). Positive NI is attributed to patients with an improvement of > 5% NI after 48 h (48.9%), while negative NI is assigned to patients values lower than − 5% (14.0%). Poor outcome was assigned to patients with mRS ≥ 3 at 3 months. We observed an inverse association of poor outcome with positive NI (OR, 0.35; 95%CI, 0.18–0.67; p = 0.002) and a direct association with negative NI (OR, 6.30; 95%CI, 2.12–18.65; p = 0.001). Negative NI showed a higher association with poor outcome than most clinical markers. Regarding good functional outcome, positive NI was the marker with the higher association (19.31; CI 95%, 9.03–41.28; p < 0.0001) and with the highest percentage of identified patients with good functional outcome (17.6%). Patients with negative NI have higher glutamate levels compared with patients with neutral and positive NI (p < 0.0001). IL6 levels are significantly lower in patients with positive NI compared with neutral NI (p < 0.0001), while patients with negative NI showed the highest IL6 values (p < 0.0001). High glutamate levels were associated with negative NI at short latency times, decreasing at higher latency times. An opposite trend was observed for inflammation, and IL6 levels were similar in patients with positive and negative NI in the first 6 h and then higher in patients with negative NI. These results support NI as a prognosis factor in IS and the hypothesis of the existence of a delayed inflammatory penumbra, opening up the possibility of extending the therapeutic window for IS.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Syed Suhail Andrabi ◽  
Suhel Parvez ◽  
Heena Tabassum

Stroke is one of the most devastating neurological disabilities and brain’s vulnerability towards it proves to be fatal and socio-economic loss of millions of people worldwide. Ischemic stroke remains at the center stage of it, because of its prevalence amongst the several other types attacking the brain. The various cascades of events that have been associated with stroke involve oxidative stress, excitotoxicity, mitochondrial dysfunction, upregulation of Ca2+level, and so forth. Melatonin is a neurohormone secreted by pineal and extra pineal tissues responsible for various physiological processes like sleep and mood behaviour. Melatonin has been implicated in various neurological diseases because of its antioxidative, antiapoptotic, and anti-inflammatory properties. We have previously reviewed the neuroprotective effect of melatonin in various models of brain injury like traumatic brain injury and spinal cord injury. In this review, we have put together the various causes and consequence of stroke and protective role of melatonin in ischemic stroke.


Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 449 ◽  
Author(s):  
Zulema Vargas-Osorio ◽  
Andrés Da Silva-Candal ◽  
Yolanda Piñeiro ◽  
Ramón Iglesias-Rey ◽  
Tomas Sobrino ◽  
...  

Neurological diseases (Alzheimer’s disease, Parkinson’s disease, and stroke) are becoming a major concern for health systems in developed countries due to the increment of ageing in the population, and many resources are devoted to the development of new therapies and contrast agents for selective imaging. However, the strong isolation of the brain by the brain blood barrier (BBB) prevents not only the crossing of pathogens, but also a large set of beneficial drugs. Therefore, an alternative strategy is arising based on the anchoring to vascular endothelial cells of nanoplatforms working as delivery reservoirs. In this work, novel injectable mesoporous nanorods, wrapped by a fluorescent magnetic nanoparticles envelope, are proposed as biocompatible reservoirs with an extremely high loading capacity, surface versatility, and optimal morphology for enhanced grafting to vessels during their diffusive flow. Wet chemistry techniques allow for the development of mesoporous silica nanostructures with tailored properties, such as a fluorescent response suitable for optical studies, superparamagnetic behavior for magnetic resonance imaging MRI contrast, and large range ordered porosity for controlled delivery. In this work, fluorescent magnetic mesoporous nanorods were physicochemical characterized and tested in preliminary biological in vitro and in vivo experiments, showing a transversal relaxivitiy of 324.68 mM−1 s−1, intense fluorescence, large specific surface area (300 m2 g−1), and biocompatibility for endothelial cells’ uptake up to 100 µg (in a 80% confluent 1.9 cm2 culture well), with no liver and kidney disability. These magnetic fluorescent nanostructures allow for multimodal MRI/optical imaging, the allocation of therapeutic moieties, and targeting of tissues with specific damage.


2020 ◽  
pp. 126-128
Author(s):  
Yu.Yu. Kobeliatskyi

Background. Stroke is a major cause of severe disability. Working capacity is restored only in 10-20 % of stroke survivors. Stroke mortality in Ukraine is twice as high as in Western Europe. About 87 % of all strokes are ischemic strokes (II). Leading risk factors for stroke include hypertension, hypercholesterolemia, smoking, obesity, and diabetes. Objective. To describe the management of acute IS (AIS) in the practice of an anesthesiologist. Materials and methods. Analysis of literature data on this issue. Results and discussion. The ideal therapeutic approach for AIS should include reperfusion, inhibition of inflammatory processes, cytoprotection, prevention of complications and their treatment. Extreme caution should be exercised during thrombolytic therapy, as thrombolysis increases the risk of intracerebral hemorrhage. However, a meta-analysis by Y. Shoujiang et al. (2018) found that symptomatic intracerebral hemorrhage occurs in 1.9 % of patients who had received intravenous recombinant tissue plasminogen activator. These hemorrhages did not increase mortality. Excellent treatment results were observed in 74.8 % of patients with AIS. According to the analysis of the VISTA database, the end result of thrombolytic therapy can be predicted based on the initial severity of stroke on the NIHHS scale. Interestingly, hemorrhagic transformation after thrombolysis is associated with lower serum calcium. Lower blood calcium levels are associated with an increased incidence of cerebral hemorrhage in patients with AIS due to atrial fibrillation or rheumatic heart disease. In the treatment of patients with AIS it is advisable to use Neurocytin (“Yuria-Pharm”), which contains citicoline and a balanced isotonic electrolyte solution. Neurocytin helps to avoid hypocalcemia and, consequently, brain hemorrhages. Citicoline is a multimodal agent with neuroprotective and neuroregenerative properties. Citicoline has a wide therapeutic window, as this substance is effective at different time and biochemical stages of the ischemic cascade. The maximum effect of citicoline is observed in cases when it is administered as early as possible after AIS in patients who cannot undergo reperfusion therapy. Citicoline is able to reduce the size of the ischemic focus in the brain. Intensive blood pressure (BP) control also reduces the risk of intracranial hemorrhages without increasing mortality, although previous studies have suggested that a rapid decrease in BP may exacerbate cerebral ischemia. Endovascular treatment of AIS in the most acute phase involves selective thrombolysis, or mechanical thrombextraction, or thromboaspiration. The therapeutic window for the last two procedures for vessels of the carotid pool is 6 hours. When deciding to perform thromboaspiration, it is mandatory to perform and evaluate computed tomography-perfusiography of the brain. About 80-85 % of patients with AIS do not meet the selection criteria for revascularization therapy. There is also no effective therapy for such patients in the acute period. In recent years, it has been proposed to replace the term “neuroprotection” with the term “brain cell cytoprotection”, as the former does not reflect the direction of the impact on all components of the neurovascular unit and white matter. A separate aspect of brain cytoprotection is protection against ischemic reperfusion injury. For this purpose, edaravon (Ksavron, “Yuria-Pharm”) is used, which eliminates free radicals, reduces calcium flow into the cells, prevents cell adhesion to the endothelium, enhances the release of nitric oxide and inhibits the inflammatory response, neutralizing all stages and consequences of ischemic stroke. In Japan, edaravon has been included into AIS treatment guidelines since 2009. T. Yamaguchi et al. (2017) found that co-administration of edaravon and recombinant tissue plasminogen activator within 4.5 hours after AIS led to less intracranial hemorrhages and better treatment outcomes. Early use of edaravon also reduces mortality. S. Kono et al. (2013) also state that edaravon may be a good adjunct to alteplase to enhance recanalization and reduce the likelihood of hemorrhagic transformation. With the administration of edaravon within the first 24 hours after stroke, one in three patients has no post-stroke sequelae, and 70 % of patients have a significant improvement in general neurological status. If edaravon is prescribed within the first 72 hours after AIS, the general condition improves significantly in half of the patients. Edaravon (Ksavron) increases the frequency of early recanalization during thrombolysis. Conclusions. 1. Citicoline is a multimodal agent with neuroprotective and neuroregenerative properties. 2. Edaravon (Ksavron) is an ischemic cascade blocker for the empirical treatment of AIS or transient ischemic attacks. 3. The combination of edaravon (Ksavron) and citicoline (Neurocytin) as part of comprehensive therapy allows to each the advanced protection of the neurovascular unit in AIS.


2021 ◽  
Vol 11 (4) ◽  
pp. 511
Author(s):  
Ricardo C. Nogueira ◽  
Lucy Beishon ◽  
Edson Bor-Seng-Shu ◽  
Ronney B. Panerai ◽  
Thompson G. Robinson

Ischemic stroke (IS) is one of the most impacting diseases in the world. In the last decades, new therapies have been introduced to improve outcomes after IS, most of them aiming for recanalization of the occluded vessel. However, despite this advance, there are still a large number of patients that remain disabled. One interesting possible therapeutic approach would be interventions guided by cerebral hemodynamic parameters such as dynamic cerebral autoregulation (dCA). Supportive hemodynamic therapies aiming to optimize perfusion in the ischemic area could protect the brain and may even extend the therapeutic window for reperfusion therapies. However, the knowledge of how to implement these therapies in the complex pathophysiology of brain ischemia is challenging and still not fully understood. This comprehensive review will focus on the state of the art in this promising area with emphasis on the following aspects: (1) pathophysiology of CA in the ischemic process; (2) methodology used to evaluate CA in IS; (3) CA studies in IS patients; (4) potential non-reperfusion therapies for IS patients based on the CA concept; and (5) the impact of common IS-associated comorbidities and phenotype on CA status. The review also points to the gaps existing in the current research to be further explored in future trials.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 482
Author(s):  
Sara Bernardo-Castro ◽  
Inês Albino ◽  
Ángela María Barrera-Sandoval ◽  
Francesca Tomatis ◽  
João André Sousa ◽  
...  

Stroke represents the second leading cause of mortality and morbidity worldwide. Ischemic strokes are the most prevalent type of stroke, and they are characterized by a series of pathological events prompted by an arterial occlusion that leads to a heterogeneous pathophysiological response through different hemodynamic phases, namely the hyperacute, acute, subacute, and chronic phases. Stroke treatment is highly reliant on recanalization therapies, which are limited to only a subset of patients due to their narrow therapeutic window; hence, there is a huge need for new stroke treatments. Nonetheless, the vast majority of promising treatments are not effective in the clinical setting due to their inability to cross the blood-brain barrier and reach the brain. In this context, nanotechnology-based approaches such as nanoparticle drug delivery emerge as the most promising option. In this review, we will discuss the current status of nanotechnology in the setting of stroke, focusing on the diverse available nanoparticle approaches targeted to the different pathological and physiological repair mechanisms involved in each of the stroke phases.


2015 ◽  
Vol 35 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Muge Yemisci ◽  
Secil Caban ◽  
Yasemin Gursoy-Ozdemir ◽  
Sevda Lule ◽  
Ramon Novoa-Carballal ◽  
...  

Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood—brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against stroke.


Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.


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