Edaravone-Encapsulated Agonistic Micelles Rescue Ischemic Brain Tissue by Tuning Blood-Brain Barrier Permeability

Brain Targeting Bacterial Extracellular Vesicles Enhance Ischemic Stroke Therapy via Efficient ROS Elimination and Suppression of Immune Infiltration

Ischemic stroke (IS) as a detrimental neurological disease is accompanied by oxidative-stress-induced injury, concurrent inflammatory response, overactivated brain immune microenvironment, and disruption of the blood-brain barrier (BBB). This cascade of events ultimately leads to neuronal death and significantly impairs the recovery of neurological function. In this study, we presented extracellular vesicles derived from the gut probiotic Lactobacillus reuteri (LrEVs) integrated with brain targeting, reactive oxygen species (ROS) scavenging, and reduced infiltration of immune cells for effective multiple therapeutic interventions of IS. LrEVs inherited peptidoglycan (PGN) specifically targeted upregulated toll-like receptor 2 (TLR2) in the injured region of the ischemic brain, achieving the effective penetration of the BBB and accumulation in the ischemic brain. In the meantime, LrEVs prevented neuronal apoptosis after stroke by scavenging ROS overproduction and modulating microglial polarization through inhibition of the MAPK and NF-κB pathways. Furthermore, LrEVs inhibited the aggregation of C-C motif chemokine ligand 2 (CCL2), reduced the infiltration of peripheral immune cells such as macrophages and neutrophils into ischemic brain tissue, and suppressed the impairment of BBB, thereby improving the overactivated brain immune microenvironment. The findings provide a vesicle that combines ROS scavenging and modulation of the immune microenvironment, showcasing the potential of gut-probiotic-derived vesicles to treat neurological damage.

(+)-Borneol enhances the protective effect of edaravone against cerebral ischemia/reperfusion injury by targeting OAT3/P-gp transporters for drug delivery into the brain

OBJECTIVES

Cerebral ischemia-reperfusion (CI/R) injury is a severe neurological condition associated with significant morbidity and mortality. Edaravone-dexborneol is a promising neuroprotective agent for alleviating CI/R injury, which composed of edaravone and (+)-borneol. Several studies have confirmed that combining edaravone with (+)-borneol can exert synergistic effects when compared to using edaravone alone. However, whether the synergistic effect is achieved through the enhanced cerebral delivery of edaravone facilitated by (+)-borneol remains unclear, and the potential binding targets need to be further explored.

METHODS

Middle cerebral artery obstruction reperfusion (MCAO/R) rats and an oxygen-glucose deprivation/reoxygenation (OGD/R) treated bEnd.3 cells were used to evaluate the synergistic effects between edaravone and (+)-borneol. The cerebral exposure of edaravone was detected using a rapid HPLC-MS/MS method. Then, we examined whether the mechanism by which (+)-borneol increases the cerebral concentration of edaravone occurs via paracellular or transcellular pathways, and we explored potential binding targets.

RESULTS

The combined administration of edaravone and (+)-borneol significantly attenuating CI/R injury both in vivo and in vitro. What captured our interest was that the co-administration of (+)-borneol increased the exposure of edaravone in cerebral infarction area. We found that the combination of (+)-borneol contributed to the maintenance of BBB integrity. The increased expressions of tight junction proteins indicated that paracellular pathway plays a limited role in the elevated cerebral edaravone concentrations. Furthermore, we found that the co-administration of (+)-borneol up-regulated the expressions of influx transporters (OAT1 and OAT3) and down-regulated the expressions of efflux transporters (P-gp and MRP1). Inhibitor experiments further confirmed that the involvement of P-gp and OAT1/3 in the transcellular transport of edaravone across BBB. Finally, we verified that (+)-borneol could directly bind to P-gp and OAT3, facilitating the entry of edaravone into brain and reducing its efflux.

CONCLUSION

This study demonstrated for the first time that (+)-borneol could enhance the concentration of edaravone in the infarcted region under conditions of CI/R. The underlying mechanisms may involve the enhancement of trans-BBB delivery of edaravone by (+)-borneol through OAT3/P-gp-mediated transcellular transport.

Brain targeted polymeric micelles as drug carriers for ischaemic stroke treatment

Ischaemic stroke is a central nervous system disease with high morbidity, recurrence and mortality rates. Thrombolytic and neuroprotective therapies are the main therapeutic strategies for ischaemic stroke, however, the poor delivery efficiency of thrombolytic and neuroprotective drugs to the brain limits their clinical application. So far, the development of nanomedicine has brought opportunities for the above challenges, which can not only realise the effective accumulation of drugs in the target site, but also improve the pharmacokinetic behaviour of the drugs. Among the most rapidly developing nanoparticles, micelles gradually emerging as an effective strategy for ischaemic stroke treatment due to their own unique advantages. This review provided an overview of targeted and response-release micelles based on the physicochemical properties of the ischaemic stroke microenvironment, summarised the targeting strategies for delivering micellar formulations to the thrombus, blood-brain barrier, and brain parenchyma, and finally described the potentials and challenges of polymeric micelles in the treatment of ischaemic stroke.

Role of Nanotechnology in Ischemic Stroke: Advancements in Targeted Therapies and Diagnostics for Enhanced Clinical Outcomes

Each year, the number of cases of strokes and deaths due to this is increasing around the world. This could be due to work stress, lifestyles, unhealthy food habits, and several other reasons. Currently, there are several traditional methods like thrombolysis and mechanical thrombectomy for managing strokes. The current approach has several limitations, like delayed diagnosis, limited therapeutic delivery, and risks of secondary injuries. So, there is a need for some effective and reliable methods for the management of strokes, which could help in early diagnosis followed by the treatment of strokes. Nanotechnology has played an immense role in managing strokes, and recently, it has emerged as a transformative solution offering innovative diagnostic tools and therapeutic strategies. Nanoparticles (NPs) belonging to several classes, including metallic (metallic and metal oxide), organic (lipids, liposome), and carbon, can cross the blood-brain barrier and may exhibit immense potential for managing various strokes. Moreover, these NPs have exhibited promise in improving imaging specificity and therapeutic delivery by precise drug delivery and real-time monitoring of treatment efficacy. Nanomaterials like cerium oxide (CeO2) and liposome-encapsulated agents have neuroprotective properties that reduce oxidative stress and promote neuroregeneration. In the present article, the authors have emphasized the significant advancements in the nanomedicine management of stroke, including NPs-based drug delivery systems, neuroprotective and neuroregenerative therapies, and multimodal imaging advancements.

4-Hydroxydictyolactone alleviates cerebral ischemia injury by regulating neuroinflammation and autophagy via AMPK signaling pathway

BACKGROUND

Cerebral ischemia (CI), a cerebrovascular disorder, is a major contributor to disability and mortality. Marine-derived compounds are an important source of new neuroprotective drug candidates. Xenicane-type diterpenes from brown algae of the genus Dictyota have exhibited potential neuroprotective effects against CI injury, attributed to their antioxidant properties. However, whether there are other underlying neuroprotective mechanisms of xenicane diterpenes against CI is still ambiguous.

PURPOSE

This study aims to elucidate the neuroprotective efficacy and mechanism of 4-hydroxydictyolactone (HDTL) in the treatment of CI.

METHODS

The LPS-induced BV2 cell model was used for anti-neuroinflammatory activity assay. Tandem Mass Tag (TMT)-based quantitative proteomics was employed to identify underlying mechanisms. The OGD/R-induced SH-SY5Y cell model and a MCAO mice model were used to assess the neuroprotective effect of HDTL against CI in vitro and in vivo.

RESULTS

HDTL reduced inflammation in LPS-stimulated BV2 cells by inhibiting the IKK/IκB/NF-κB pathway and by enhancing AMPK phosphorylation. Additionally, in SH-SY5Y cells treated with OGD/R, HDTL facilitated autophagy and reduced apoptosis. The neuroprotective properties of HDTL were abrogated in AMPK- silenced SH-SY5Y cells. In MCAO mice, HDTL ameliorated CI injury as evidenced by decreases in neurological deficit scores and cerebral infarction. HDTL also promoted autophagy and reduced apoptosis in vivo through both the AMPK/mTOR and IKK/IκB/NF-κB pathways.

CONCLUSION

HDTL exhibits neuroprotective effects through regulating the AMPK/mTOR and IKK/IκB/NF-κB pathways. These findings suggest that HDTL is a promising therapeutic candidate for CI treatment.

Targeting glioblastoma with a brain-penetrant drug that impairs brain tumor stem cells via NLE1-Notch1 complex

Brain tumor stem cells (BTSCs) are a population of self-renewing malignant stem cells that play an important role in glioblastoma tumor hierarchy and contribute to tumor growth, therapeutic resistance, and tumor relapse. Thus, targeting of BTSCs within the bulk of tumors represents a crucial therapeutic strategy. Here, we report that edaravone is a potent drug that impairs BTSCs in glioblastoma. We show that edaravone inhibits the self-renewal and growth of BTSCs harboring a diverse range of oncogenic mutations without affecting non-oncogenic neural stem cells. Global gene expression analysis revealed that edaravone significantly alters BTSC transcriptome and attenuates the expression of a large panel of genes involved in cell cycle progression, stemness, and DNA repair mechanisms. Mechanistically, we discovered that edaravone directly targets Notchless homolog 1 (NLE1) and impairs Notch signaling pathway, alters the expression of stem cell markers, and sensitizes BTSC response to ionizing radiation (IR)-induced cell death. Importantly, we show that edaravone treatment in preclinical models delays glioblastoma tumorigenesis, sensitizes their response to IR, and prolongs the lifespan of animals. Our data suggest that repurposing of edaravone is a promising therapeutic strategy for patients with glioblastoma.

Nuclear factor erythroid 2-related factor-mediated signaling alleviates ferroptosis during cerebral ischemia-reperfusion injury

Cardiac arrest (CA) is a significant challenge for emergency physicians worldwide and leads to increased morbidity and mortality rates. The poor prognosis of CA primarily stems from the complexity and irreversibility of cerebral ischemia-reperfusion injury (CIRI). Ferroptosis, a form of programmed cell death characterized by iron overload and lipid peroxidation, plays a crucial role in the progression and treatment of CIRI. In this review, we highlight the mechanisms of ferroptosis within the context of CIRI, focusing on its role as a key contributor to neuronal damage and dysfunction post-CA. We explore the crucial involvement of the nuclear factor erythroid 2-related factor (Nrf2)-mediated signaling pathway in modulating ferroptosis-associated processes during CIRI. Through comprehensive analysis of the regulatory role of Nrf2 in the cellular responses to oxidative stress, we highlight its potential as a therapeutic target for mitigating ferroptotic cell death and improving the neurological prognosis of patients experiencing CA. Furthermore, we discuss interventions targeting the Kelch-like ECH-associated protein 1/Nrf2/antioxidant response element pathway, including the use of traditional Chinese medicine and Western medicine, which demonstrate potential for attenuating ferroptosis and preserving neuronal function in CIRI. Owing to the limitations in the safety, specificity, and effectiveness of Nrf2-targeted drugs, as well as the technical difficulties and ethical constraints in obtaining the results related to the brain pathological examination of patients, most of the studies focusing on Nrf2-related regulation of ferroptosis in CIRI are still in the basic research stage. Overall, this review aims to provide a comprehensive understanding of the mechanisms underlying ferroptosis in CIRI, offering insights into novel therapeutics aimed at enhancing the clinical outcomes of patients with CA.

Research progress on pharmacological effects and bioavailability of berberine

Berberine (BBR), a benzylisoquinoline alkaloid obtained from natural medicines such as coptidis rhizoma, has a wide range of pharmacological activities such as protecting the nervous system, protecting the cardiovascular system, anti-inflammatory, antidiabetic, antihyperlipidemic, antitumor, antibacterial, and antidiarrheal. However, factors such as poor solubility, low permeability, P-glycoprotein (P-gp) efflux, and hepatic-intestinal metabolism result in BBR having a low bioavailability (< 1%), which restricts its application in clinical settings. Therefore, improving its bioavailability is a prerequisite for its clinical applications. This review summarizes the various pharmacological effects of BBR and analyzes the main reasons for its poor bioavailability. It introduces methods to improve the bioavailability of BBR through the use of absorption enhancers and P-gp inhibitors, structural modification of BBR, and preparation of BBR salts and cocrystals as well as the development of new formulations and focuses on the bioavailability study of the new formulations of BBR. The research of BBR was also prospected in order to provide reference for the further research of BBR.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Edaravone: A Possible Treatment for Acute Lung Injury

Despite technological advances in science and medicine, acute lung injury (ALI) is still associated with high mortality rates in the ICU. Therefore, finding novel drugs and treatment approaches is crucial to preventing ALI. Drug repurposing is a common practice in clinical research, primarily for drugs that have previously received approval for use in patients, to investigate novel uses of drugs and therapies. One such medication is edaravone, which is a highly effective free-radical scavenger that also has anti-inflammatory, anti-apoptotic, antioxidant, and anti-fibrotic effects. Both basic and clinical studies have shown that edaravone can treat different types of lung injury through its distinct properties. Edaravone exhibits significant protective benefits and holds promising clinical treatment potential for ALI caused by diverse factors, thereby offering a novel approach to treating ALI. This study aims to provide new insights and treatment options for ALI by reviewing both basic and clinical research on the use of edaravone. The focus is on evaluating the effectiveness of edaravone in treating ALI caused by various factors.

Targeted pathophysiological treatment of ischemic stroke using nanoparticle-based drug delivery system

Ischemic stroke poses significant challenges in terms of mortality and disability rates globally. A key obstacle to the successful treatment of ischemic stroke lies in the limited efficacy of administering therapeutic agents. Leveraging the unique properties of nanoparticles for brain targeting and crossing the blood-brain barrier, researchers have engineered diverse nanoparticle-based drug delivery systems to improve the therapeutic outcomes of ischemic stroke. This review provides a concise overview of the pathophysiological mechanisms implicated in ischemic stroke, encompassing oxidative stress, glutamate excitotoxicity, neuroinflammation, and cell death, to elucidate potential targets for nanoparticle-based drug delivery systems. Furthermore, the review outlines the classification of nanoparticle-based drug delivery systems according to these distinct physiological processes. This categorization aids in identifying the attributes and commonalities of nanoparticles that target specific pathophysiological pathways in ischemic stroke, thereby facilitating the advancement of nanomedicine development. The review discusses the potential benefits and existing challenges associated with employing nanoparticles in the treatment of ischemic stroke, offering new perspectives on designing efficacious nanoparticles to enhance ischemic stroke treatment outcomes.

Safety and efficacy of GD-11 in patients with ischaemic stroke: a multicentre, double-blind, randomised, placebo-controlled, phase 2 trial

BACKGROUND

GD-11, a novel brain cytoprotective drug, was designed to be actively taken up and transported across the blood-brain barrier via the glucose transporter. This study aimed to evaluate the safety and efficacy of GD-11 for improving the recovery of patients with acute ischaemic stroke (AIS).

METHODS

A double-blind, randomised, placebo-controlled, phase 2 trial was conducted at 15 clinical sites in China. Patients aged 18-80 years with AIS within 48 hours were randomly assigned (1:1:1) to receive 160 mg GD-11, 80 mg GD-11 and placebo, two times a day for 10 days. The primary endpoint was a modified Rankin Scale (mRS) score of 0-1 at 90 days after treatment. The safety outcome was any adverse events within 90 days.

RESULTS

From 17 November 2022 to 22 March 2023, a total of 80 patients in the 160 mg GD-11 group, 79 patients in the 80 mg GD-11 group and 80 patients in the placebo group were included. The proportion of an mRS score of 0-1 at day 90 was 77.5% in the 160 mg GD-11 group, 72.2% in the 80 mg GD-11 group and 67.5% in the placebo group. Though no significant difference was found (p=0.3671), a numerically higher proportion was observed in the GD-11 group, especially in the 160 mg GD-11 group. The incidence of adverse events was similar across the three groups (p=0.1992).

CONCLUSION

GD-11 was safe and well-tolerated. A dosage of GD-11 160 mg two times a day was recommended for a large trial to investigate the efficacy.

Polymeric nanocarriers delivery systems in ischemic stroke for targeted therapeutic strategies

Ischemic stroke is a complex, high-mortality disease with multifactorial etiology and pathogenesis. Currently, drug therapy is mainly used treat ischemic stroke in clinic, but there are still some limitations, such as limited blood-brain barrier (BBB) penetration efficiency, a narrow treatment time window and drug side effects. Recent studies have pointed out that drug delivery systems based on polymeric nanocarriers can effectively improve the insufficient treatment for ischemic stroke. They can provide neuronal protection by extending the plasma half-life of drugs, enhancing the drug's permeability to penetrate the BBB, and targeting specific structures and cells. In this review, we classified polymeric nanocarriers used for delivering ischemic stroke drugs and introduced their preparation methods. We also evaluated the feasibility and effectiveness and discussed the existing limitations and prospects of polymeric nanocarriers for ischemic stroke treatment. We hoped that this review could provide a theoretical basis for the future development of nanomedicine delivery systems for the treatment of ischemic stroke.

Edaravone dexborneol protects against cerebral ischemia/reperfusion-induced blood-brain barrier damage by inhibiting ferroptosis via activation of nrf-2/HO-1/GPX4 signaling

PURPOSE

Ferroptosis has recently been recognized as a mechanism of cerebral ischemia-reperfusion (I/R) injury, attributed to blood-brain barrier (BBB) disruption. Edaravone dexboneol (Eda.B) is a novel neuroprotective agent widely employed in ischemic stroke, which is composed of edaravone (Eda) and dexborneol. This study aimed to investigate the protective effects of Eda.B on the BBB in cerebral I/R and explore its potential mechanisms.

METHODS

Transient middle cerebral artery occlusion (tMCAO) Sprague-Dawley-rats model was used. Rats were randomly assigned to sham-operated group (sham, n = 20), model group (tMCAO, n = 20), Eda.B group (Eda.B, n = 20), Eda group (Eda, n = 20) and dexborneol group (dexborneol, n = 20), and Eda.B + Zinc protoporphyria group (Eda.B + ZnPP, n = 5). Infarct area, cellular apoptosis and neurofunctional recovery were accessed through TTC staining, TUNEL staining, and modified Garcia scoring system, respectively. BBB integrity was evaluated via Evans blue staining. Nuclear factor E2 related factor 2 (Nrf-2)/heme oxygenase 1 (HO-1)/glutathione peroxidase 4 (GPX4) signaling were qualified by Western blot. Transmission electron microscopy (TEM) revealed alterations in ipsilateral brain tissue among groups. Glutathione (GSH) and malondialdehyde (MDA) levels, and Fe2+ tissue content determination were detected.

RESULTS

Eda.B effectively improved neurological deficits, diminished infarct area and cellular apoptosis, as well as ameliorated BBB integrity in tMCAO rats. Further, Eda.B significantly inhibited ferroptosis, as evidenced by ameliorated pathological features of mitochondria, down-regulated of MDA and Fe2+ levels and up-regulated GSH content. Mechanistically, Eda.B attenuated BBB disruption via Nrf-2-mediated ferroptosis, promoting nuclear translocation of Nrf-2, increasing HO-1, GPX4 expression, alleviating the loss of zonula occludens 1 (ZO-1) and occludin as well as decreasing 4-hydroxynonenal (4-HNE) level.

CONCLUSIONS

This study revealed for the first time that Eda.B safeguarded the BBB from cerebral I/R injury by inhibiting ferroptosis through the activation of the Nrf-2/HO-1/GPX4 axis, providing a novel insight into the neuroprotective effect of Eda.B in cerebral I/R.

Berberine Effects in Pre-Fibrotic Stages of Non-Alcoholic Fatty Liver Disease-Clinical and Pre-Clinical Overview and Systematic Review of the Literature

Non-alcoholic fatty liver disease (NAFLD) is the predominant cause of chronic liver conditions, and its progression is marked by evolution to non-alcoholic steatosis, steatohepatitis, cirrhosis related to non-alcoholic steatohepatitis, and the potential occurrence of hepatocellular carcinoma. In our systematic review, we searched two databases, Medline (via Pubmed Central) and Scopus, from inception to 5 February 2024, and included 73 types of research (nine clinical studies and 64 pre-clinical studies) from 2854 published papers. Our extensive research highlights the impact of Berberine on NAFLD pathophysiology mechanisms, such as Adenosine Monophosphate-Activated Protein Kinase (AMPK), gut dysbiosis, peroxisome proliferator-activated receptor (PPAR), Sirtuins, and inflammasome. Studies involving human subjects showed a measurable reduction of liver fat in addition to improved profiles of serum lipids and hepatic enzymes. While current drugs for NAFLD treatment are either scarce or still in development or launch phases, Berberine presents a promising profile. However, improvements in its formulation are necessary to enhance the bioavailability of this natural substance.

Edaravone-loaded poly(amino acid) nanogel inhibits ferroptosis for neuroprotection in cerebral ischemia injury

Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood-brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.

Edaravone: A Novel Possible Drug for Cancer Treatment?

Despite significant advancements in understanding the causes and progression of tumors, cancer remains one of the leading causes of death worldwide. In light of advances in cancer therapy, there has been a growing interest in drug repurposing, which involves exploring new uses for medications that are already approved for clinical use. One such medication is edaravone, which is currently used to manage patients with cerebral infarction and amyotrophic lateral sclerosis. Due to its antioxidant and anti-inflammatory properties, edaravone has also been investigated for its potential activities in treating cancer, notably as an anti-proliferative and cytoprotective drug against side effects induced by traditional cancer therapies. This comprehensive review aims to provide updates on the various applications of edaravone in cancer therapy. It explores its potential as a standalone antitumor drug, either used alone or in combination with other medications, as well as its role as an adjuvant to mitigate the side effects of conventional anticancer treatments.

Selenium Nanoparticles in Protecting the Brain from Stroke: Possible Signaling and Metabolic Mechanisms

Strokes rank as the second most common cause of mortality and disability in the human population across the world. Currently, available methods of treating or preventing strokes have significant limitations, primarily the need to use high doses of drugs due to the presence of the blood-brain barrier. In the last decade, increasing attention has been paid to the capabilities of nanotechnology. However, the vast majority of research in this area is focused on the mechanisms of anticancer and antiviral effects of nanoparticles. In our opinion, not enough attention is paid to the neuroprotective mechanisms of nanomaterials. In this review, we attempted to summarize the key molecular mechanisms of brain cell damage during ischemia. We discussed the current literature regarding the use of various nanomaterials for the treatment of strokes. In this review, we examined the features of all known nanomaterials, the possibility of which are currently being studied for the treatment of strokes. In this regard, the positive and negative properties of nanomaterials for the treatment of strokes have been identified. Particular attention in the review was paid to nanoselenium since selenium is a vital microelement and is part of very important and little-studied proteins, e.g., selenoproteins and selenium-containing proteins. An analysis of modern studies of the cytoprotective effects of nanoselenium made it possible to establish the mechanisms of acute and chronic protective effects of selenium nanoparticles. In this review, we aimed to combine all the available information regarding the neuroprotective properties and mechanisms of action of nanoparticles in neurodegenerative processes, especially in cerebral ischemia.

Nanotechnology-empowered therapeutics targeting neurodegenerative diseases

Neurodegenerative diseases are posing pressing health issues due to the high prevalence among aging populations in the 21st century. They are evidenced by the progressive loss of neuronal function, often associated with neuronal necrosis and many related devastating complications. Nevertheless, effective therapeutical strategies to treat neurodegenerative diseases remain a tremendous challenge due to the multisystemic nature and limited drug delivery to the central nervous system. As a result, there is a pressing need to develop effective alternative therapeutics to manage the progression of neurodegenerative diseases. By utilizing the functional reconstructive materials and technologies with specific targeting ability at the nanoscale level, nanotechnology-empowered medicines can transform the therapeutic paradigms of neurodegenerative diseases with minimal systemic side effects. This review outlines the current applications and progresses of the nanotechnology-enabled drug delivery systems to enhance the therapeutic efficacy in treating neurodegenerative diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Inhibition of autophagy and RIP1/RIP3/MLKL-mediated necroptosis by edaravone attenuates blood spinal cord barrier disruption following spinal cord injury

The disruption of the blood spinal cord barrier (BSCB) after spinal cord injury (SCI) can trigger secondary tissue damage. Edaravone is likely to protect the BSCB as a free radical scavenger, whereas it has been rarely reported thus far. In this study, the protective effect of edaravone was investigated with the use of compression spinal cord injured rats and human brain microvascular endothelial cells (HBMECs) injury. As indicated by the result of this study, edaravone treatment facilitated functional recovery after rats were subjected to SCI, ameliorated the vascular damage, and up-regulated the expression of BSCB-associated proteins. In vitro results, edaravone improved HBMECs viability, restored intercellular junctions, and promoted cellular angiogenic activities. It is noteworthy that autophagy was activated and RIP1/RIP3/MLKL phosphorylation was notably up-regulated. However, edaravone treatment exhibited the capability of mitigating above-mentioned tendency in vivo and in vitro. Moreover, rapamycin (Rapa) treatment deteriorated the protective effect of edaravone while aggravating the phosphorylation of RIP1/RIP3/MLKL expression. In the model of necrotic activator-induced HBMECs, autophagic expression was increased, whereas edaravone prevented autophagy and phosphorylation of RIP1/RIP3/MLKL. In general, our results suggested that edaravone is capable of reducing the destruction of BSCB and promoting functional recovery after SCI. The possible underlying mechanism is that edaravone is capable of protecting angiogenic activity and improving autophagy and the phosphorylation of RIP1/RIP3/MLKL, as well as their mutual deterioration. Accordingly, edaravone can be a favorable option for the treatment of SCI.

Intranasal administration of edaravone nanoparticles improves its stability and brain bioavailability

The clinical application of EDV, a potent antioxidant drug approved for amyotrophic lateral sclerosis (ALS), is limited by its short biological half-life and poor water solubility necessitating hospitalization during intravenous infusion. Nanotechnology-based drug delivery constitutes a powerful tool through inferring drug stability and targeted drug delivery improving drug bioavailability at the diseased site. Nose-to-brain drug delivery offers direct access to the brain bypassing the blood brain barrier and reducing systemic biodistribution. In this study, we designed EDV-loaded poly(lactic-co-glycolic acid) (PLGA)-based polymeric nanoparticles (NP-EDV) for intranasal administration. NPs were formulated by the nanoprecipitation method. Morphology, EDV loading, physicochemical properties, shelf-life stability, in vitro release and pharmacokinetic assessment in mice were conducted. EDV was efficiently loaded into ∼90 nm NPs, stable up to 30 days of storage, at ∼3% drug loading. NP-EDV reduced H2O2-induced oxidative stress toxicity in mouse microglial cell line BV-2. Optical imaging and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) showed that intranasal delivery of NP-EDV offered higher and more sustained brain uptake of EDV compared to intravenous administration. This study is the first of its kind to develop an ALS drug in a nanoparticulate formulation for nose-to-brain delivery raising hope to ALS patients where currently treatment options are limited to two clinically approved drugs only.

The protection impact of tectoridin on PC12 cell preventing OGD/R-caused damage through PI3K/AKT signaling channel

The present work examined the effect exerted by tectoridin preventing oxygen glucose deprivation/reoxygenation (OGD/R) damage within PC12 cell. We incubated PC12 cells with Na₂S₂O₄ (10 mM) for 2 h, and tectoridin at different concentrations was then added; based on methyl-thiazolyl-tetrazolium (MTT) and lactate dehydrogenase (LDH) tests, the protection impact was tested. 2',7'-dicholorofluorescein diacetate (DCFH-DA), Fluo-3AM, and 5, 5', 6, 6' -tetrachloro-1, 1', 3, 3' -tetraethyl-imidacarbocyanine iodide (JC-1) staining, and Western blotting were used for determining reactive oxygen species (ROS) level, intracellular Ca²⁺ content, mitochondrial membrane potential (MMP) and the related proteins contents. As a result, tectoridin could improve the cell viability and inhibit the release of LDH. In-depth studies demonstrated that tectoridin limited the overproduction of ROS and intracellular Ca²⁺ content and increased MMP, which showed a close association with ROS-mediated mitochondrial function. Moreover, tectoridin hindered apoptosis based on the up-regulation of the expressions of p-AKT, Bcl-2/Bax and p-mTOR. Furthermore, the level of Nrf2 was also improved by treatment of tectoridin. In addition, the expression of Bcl-2/Bax, p-Akt, p-mTOR, Nrf2, HO-1, NQO1 and GCLM were reduced by LY294002 and the protective role of tectoridin was limited by LY294002. The results unambiguously suggested that tectoridin reduced OGD/R-caused damage to PC12 cells and might ensure neuroprotection by stimulating the PI3K/AKT signaling channel.

Harnessing nanobiotechnology for cerebral ischemic stroke management

Cerebral ischemic stroke remains one of the most serious neurological disorders that pose threats to human health, causing a large amount of long-term disability or even death throughout the world. Based on its physiologic and pathological features, there are limited available therapeutic options for effective ischemic stroke management. Encouragingly, a rapid advancement of nanobiotechnology is bringing new insights into exploring more alternative strategies against cerebral ischemic stroke, which can cleverly overcome the limitations related to conventional treatment methods. Therefore, this review focuses on the recent achievements of nanobiotechnology for ischemic stroke management, which emphasizes diverse targeted delivery strategies using various nanoplatforms including liposomes, micelles, polymeric nanoparticles, nanogels, inorganic nanomaterials, and cell-derived nano-vectors based on the pathophysiological features of ischemic stroke. Moreover, different therapeutic approaches against ischemic stroke such as neuroprotection, anti-inflammation, thrombolysis, increased blood-brain barrier penetration and reactive oxygen species scavenging are highlighted. Meanwhile, this review discusses how these versatile nanoplatforms were designed to assist in the treatment of ischemic stroke. Based on this, challenges, opportunities, and future perspectives using nanobiotechnology through rational design for effective ischemic stroke management are revealed.

Guiding Epilepsy Surgery with an LRP1-Targeted SPECT/SERRS Dual-Mode Imaging Probe

Accurate identification of the resectable epileptic lesion is a precondition of operative intervention to drug-resistant epilepsy (DRE) patients. However, even when multiple diagnostic modalities are combined, epileptic foci cannot be accurately identified in ∼30% of DRE patients. Inflammation-associated low-density lipoprotein receptor-related protein-1 (LRP1) has been validated to be a surrogate target for imaging epileptic foci. Here, we reported an LRP1-targeted dual-mode probe that is capable of providing comprehensive epilepsy information preoperatively with SPECT imaging while intraoperatively delineating epileptic margins in a sensitive high-contrast manner with surface-enhanced resonance Raman scattering (SERRS) imaging. Notably, a novel and universal strategy for constructing self-assembled monolayer (SAM)-based Raman reporters was proposed for boosting the sensitivity, stability, reproducibility, and quantifiability of the SERRS signal. The probe showed high efficacy to penetrate the blood-brain barrier. SPECT imaging showed the probe could delineate the epileptic foci clearly with a high target-to-background ratio (4.11 ± 0.71, 2 h). Further, with the assistance of the probe, attenuated seizure frequency in the epileptic mouse models was achieved by using SPECT together with Raman images before and during operation, respectively. Overall, this work highlights a new strategy to develop a SPECT/SERRS dual-mode probe for comprehensive epilepsy surgery that can overcome the brain shift by the co-registration of preoperative SPECT and SERRS intraoperative images.

Micro-Nanocarriers Based Drug Delivery Technology for Blood-Brain Barrier Crossing and Brain Tumor Targeting Therapy

The greatest obstacle to using drugs to treat brain tumors is the blood-brain barrier (BBB), making it difficult for conventional drug molecules to enter the brain. Therefore, how to safely and effectively penetrate the BBB to achieve targeted drug delivery to brain tumors has been a challenging research problem. With the intensive research in micro- and nanotechnology in recent years, nano drug-targeted delivery technologies have shown great potential to overcome this challenge, such as inorganic nanocarriers, organic polymer-carriers, liposomes, and biobased carriers, which can be designed in different sizes, shapes, and surface functional groups to enhance their ability to penetrate the BBB and targeted drug delivery for brain tumors. In this review, the composition and overcoming patterns of the BBB are detailed, and then the hot research topics of drug delivery carriers for brain tumors in recent years are summarized, and their mechanisms of action on the BBB and the factors affecting drug delivery are described in detail, and the effectiveness of targeted therapy for brain tumors is evaluated. Finally, the challenges and dilemmas in developing brain tumor drug delivery systems are discussed, which will be promising in the future for targeted drug delivery to brain tumors based on micro-nanocarriers technology.

Targeted Therapy of Ischemic Stroke via Crossing the Blood-Brain Barrier Using Edaravone-Loaded Multiresponsive Microgels

Ischemic stroke, as a prevalent neurological disorder, often results in rapid increases in the production of reactive oxygen species (ROS) and inflammatory factors in the focal ischemic area. Though edaravone is an approved treatment, its effect is limited due to its weak ability to cross the blood-brain barrier (BBB) and short half-life. Other effective pharmacological treatment options are clearly lacking. In this study, PNIVDBrF-3-Eda (also named MG-3-Eda) was prepared using a thermo- and pH dual-responsive PNIVDBrF microgel. These were designed with a positively charged network, as synthesized by simultaneous quaternization cross-linking and surfactant-free emulsion copolymerization, to be loaded with the negatively charged edaravone. We then investigated whether such a targeted delivery of edaravone could provide enhanced neuroprotection. Cytotoxicity assays confirmed that the microgel (<1 mg/mL) exhibited promising cytocompatibility with no remarkable effect on cell viability, cell cycle regulation, or apoptosis levels. In vitro and in vivo experiments demonstrated that the microgels could successfully penetrate the blood-brain barrier where efficient BBB crossing was observed after disruption of the BBB due to ischemic injury. This enabled MG-3-Eda to target the cerebral ischemic area and achieve local release of edaravone. Treatment with MG-3-Eda significantly reduced the cerebral infarct area in transient middle cerebral artery occlusion (tMCAO) mice and significantly improved behavioral scores. MG-3-Eda treatment also prevented the reduction in NF200 expression, a neuronal marker protein, and attenuated microglia activation (as detected by Iba1) in the local ischemic area via local antioxidant and anti-inflammatory effects. A superior neuroprotective effect was noted for MG-3-Eda compared to that for free edaravone. Our results indicate that MG-3-Eda administration represents a clear potential treatment for cerebral ischemia via its targeted delivery of edaravone to ischemic areas where it provides significant local antioxidant and anti-inflammatory effects.

Recent Advances in Targeted Nanotherapies for Ischemic Stroke

Ischemic stroke (IS) is a severe neurological disease caused by the narrowing or occlusion of cerebral blood vessels and is known for high morbidity, disability, and mortality rates. Clinically available treatments of stroke include the surgical removal of the thrombus and thrombolysis with tissue fibrinogen activator. Pharmaceuticals targeting IS are uncommon, and the development of new therapies is hindered by the low bioavailability and stability of many drugs. Nanomedicine provides new opportunities for the development of novel neuroprotective and thrombolytic strategies for the diagnosis and treatment of IS. Numerous nanotherapeutics with different physicochemical properties are currently being developed to facilitate drug delivery by accumulation and controlled release and to improve their restorative properties. In this review, we discuss recent developments in IS therapy, including assisted drug delivery and targeting, neuroprotection through regulation of the neuron environment, and sources of endogenous biomimetic specific targeting. In addition, we discuss the role and neurotoxic effects of inorganic metal nanoparticles in IS therapy. This study provides a theoretical basis for the utilization of nano-IS therapies that may contribute to the development of new strategies for a range of embolic diseases.

Postischemic Neuroprotection of Aminoethoxydiphenyl Borate Associates Shortening of Peri-Infarct Depolarizations

Brain stroke is a highly prevalent pathology and a main cause of disability among older adults. If not promptly treated with recanalization therapies, primary and secondary mechanisms of injury contribute to an increase in the lesion, enhancing neurological deficits. Targeting excitotoxicity and oxidative stress are very promising approaches, but only a few compounds have reached the clinic with relatively good positive outcomes. The exploration of novel targets might overcome the lack of clinical translation of previous efficient preclinical neuroprotective treatments. In this study, we examined the neuroprotective properties of 2-aminoethoxydiphenyl borate (2-APB), a molecule that interferes with intracellular calcium dynamics by the antagonization of several channels and receptors. In a permanent model of cerebral ischemia, we showed that 2-APB reduces the extent of the damage and preserves the functionality of the cortical territory, as evaluated by somatosensory evoked potentials (SSEPs). While in this permanent ischemia model, the neuroprotective effect exerted by the antioxidant scavenger cholesteronitrone F2 was associated with a reduction in reactive oxygen species (ROS) and better neuronal survival in the penumbra, 2-APB did not modify the inflammatory response or decrease the content of ROS and was mostly associated with a shortening of peri-infarct depolarizations, which translated into better cerebral blood perfusion in the penumbra. Our study highlights the potential of 2-APB to target spreading depolarization events and their associated inverse hemodynamic changes, which mainly contribute to extension of the area of lesion in cerebrovascular pathologies.

Preclinical Characterization of Antioxidant Quinolyl Nitrone QN23 as a New Candidate for the Treatment of Ischemic Stroke

Nitrones are encouraging drug candidates for the treatment of oxidative stress-driven diseases such as acute ischemic stroke (AIS). In a previous study, we found a promising quinolylnitrone, QN23, which exerted a neuroprotective effect in neuronal cell cultures subjected to oxygen–glucose deprivation and in experimental models of cerebral ischemia. In this paper, we update the biological and pharmacological characterization of QN23. We describe the suitability of intravenous administration of QN23 to induce neuroprotection in transitory four-vessel occlusion (4VO) and middle cerebral artery occlusion (tMCAO) experimental models of brain ischemia by assessing neuronal death, apoptosis induction, and infarct area, as well as neurofunctional outcomes. QN23 significantly decreased the neuronal death and apoptosis induced by the ischemic episode in a dose-dependent manner and showed a therapeutic effect when administered up to 3 h after post-ischemic reperfusion onset, effects that remained 11 weeks after the ischemic episode. In addition, QN23 significantly reduced infarct volume, thus recovering the motor function in a tMCAO model. Remarkably, we assessed the antioxidant activity of QN23 in vivo using dihydroethidium as a molecular probe for radical species. Finally, we describe QN23 pharmacokinetic parameters. All these results pointing to QN23 as an interesting and promising preclinical candidate for the treatment of AIS.

The therapeutic benefits of intravenously administrated nanoparticles in stroke and age-related neurodegenerative diseases

The mean global lifetime risk of neurological disorders such as stroke, Alzheimer's disease (AD), and Parkinson's disease (PD) has shown a large effect on economy and society.Researchersare stillstruggling to find effective drugs to treatneurological disordersand drug delivery through the blood-brain barrier (BBB) is a major challenge to be overcome. The BBB is a specialized multicellular barrier between the peripheral blood circulation and the neural tissue. Unique and selective features of the BBB allow it to tightly control brain homeostasis as well as the movement of ions and molecules. Failure in maintaining any of these substances causes BBB breakdown and subsequently enhances neuroinflammation and neurodegeneration.BBB disruption is evident in many neurologicalconditions.Nevertheless, the majority of currently available therapies have tremendous problems for drug delivery into the impaired brain. Nanoparticle (NP)-mediated drug delivery has been considered as a profound substitute to solve this problem. NPs are colloidal systems with a size range of 1-1000 nm whichcan encapsulate therapeutic payloads, improve drug passage across the BBB, and target specific brain areas in neurodegenerative/ischemic diseases. A wide variety of NPs has been displayed for the efficient brain delivery of therapeutics via intravenous administration, especially when their surfaces are coated with targeting moieties. Here, we discuss recent advances in the development of NP-based therapeutics for the treatment of stroke, PD, and AD as well as the factors affecting their efficacy after systemic administration.

Advances of nano drug delivery system for the theranostics of ischemic stroke

From the global perspective, stroke refers to a highly common cause of disability and death. Ischemic stroke (IS), attributed to blood vessel blockage, preventing the flow of blood to brain, acts as the most common form of stroke. Thus far, thrombolytic therapy is the only clinical treatment for IS with the approval from the FDA. Moreover, the physiology barrier complicates therapeutically and diagnostically related intervention development of IS. Accordingly, developing efficient and powerful curative approaches for IS diagnosis and treatment is urgently required. The advent of nanotechnology has brought dawn and hope to better curative and imaging forms for the management of IS. This work reviews the recent advances and challenges correlated with the nano drug delivery system for IS therapy and diagnosis. The overview of the current knowledge of the important molecular pathological mechanisms in cerebral ischemia and how the drugs cross the blood brain barrier will also be briefly summarized.

Transferrin-Enabled Blood–Brain Barrier Crossing Manganese-Based Nanozyme for Rebalancing the Reactive Oxygen Species Level in Ischemic Stroke

(1) Background: Acute ischemic stroke (IS) is one of the main causes of human disability and death. Therefore, multifunctional nanosystems that effectively cross the blood–brain barrier (BBB) and efficiently eliminate reactive oxygen species (ROS) are urgently needed for comprehensive neuroprotective effects. (2) Methods: We designed a targeted transferrin (Tf)-based manganese dioxide nanozyme (MnO2@Tf, MT) using a mild biomimetic mineralization method for rebalancing ROS levels. Furthermore, MT can be efficiently loaded with edaravone (Eda), a clinical neuroprotective agent, to obtain the Eda-MnO2@Tf (EMT) nanozyme. (3) Results: The EMT nanozyme not only accumulates in a lesion area and crosses the BBB but also possesses satisfactory biocompatibility and biosafety based on the functional inheritance of Tf. Meanwhile, EMT has intrinsic hydroxyl radical-scavenging ability and superoxide-dismutase-like and catalase-like nanozyme abilities, allowing it to ameliorate ROS-mediated damage and decrease inflammatory factor levels in vivo. Moreover, the released Mn2+ ions in the weak acid environment of the lesion area can be used for magnetic resonance imaging (MRI) to monitor the treatment process. (4) Conclusions: Our study not only paves a way to engineer alternative targeted ROS scavengers for intensive reperfusion-induced injury in ischemic stroke but also provides new insights into the construction of bioinspired Mn-based nanozymes.

Brain-targeting drug delivery systems

Brain diseases, including neurodegenerative diseases, acute ischemic stroke and brain tumors, have become a major health problem and a huge burden on society with high morbidity and mortality. However, most of the current therapeutic drugs can only relieve the symptoms of brain diseases, and it is difficult to achieve satisfactory therapeutic effects fundamentally. Extensive studies have shown that the therapeutic effects of brain diseases are mainly affected by two factors: the conservation of the blood-brain barrier (BBB) and the complexity of the brain micro-environment. Brain-targeting drug delivery systems provide new possibilities for overcoming these barriers with versatility. In this review, it provides an overview of BBB alteration and discusses targeting delivery strategies for brain diseases therapy. Furthermore, delivery systems which are designed to modulate the brain micro-environment with synergistic effects were also highlighted. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Targeted delivery of edaravone by liposomes for the treatment of ischemic stroke

Aim: To construct an edaravone-encapsulated liposomes (EDV-LIPs) formulation against acute ischemic stroke. Methods: EDV-LIPs were prepared by the film dispersion method. The biosafety was evaluated both in vitro and in vivo by flow cytometry and the histological staining method. Biodistribution and therapeutic effect of EDV-LIPs against acute ischemic stroke was investigated by fluorescent imaging, the behavior test, laser speckle imaging and triphenyltetrazolium chloride staining. Results: The nanoliposomes had a long circulation time and could accumulate in the brain lesion region in ischemic stroke rats. EDV-LIPs show good biosafety. EDV-LIPs could restore more cerebral blood flow, reduce infarct volume and decrease neuronal apoptosis. Conclusion: EDV-LIPs provide an effective alternative for drug-targeted delivery against acute ischemic stroke.

Lipid-Based Nanocarriers for Neurological Disorders: A Review of the State-of-the-Art and Therapeutic Success to Date

Neurodegenerative disorders including Alzheimer's, Parkinson's, and dementia are chronic and advanced diseases that are associated with loss of neurons and other related pathologies. Furthermore, these disorders involve structural and functional defections of the blood-brain barrier (BBB). Consequently, advances in medicines and therapeutics have led to a better appreciation of various pathways associated with the development of neurodegenerative disorders, thus focusing on drug discovery and research for targeted drug therapy to the central nervous system (CNS). Although the BBB functions as a shield to prevent toxins in the blood from reaching the brain, drug delivery to the CNS is hindered by its presence. Owing to this, various formulation approaches, including the use of lipid-based nanocarriers, have been proposed to address shortcomings related to BBB permeation in CNS-targeted therapy, thus showing the potential of these carriers for translation into clinical use. Nevertheless, to date, none of these nanocarriers has been granted market authorization following the successful completion of all stages of clinical trials. While the aforementioned benefits of using lipid-based carriers underscores the need to fast-track their translational development into clinical practice, technological advances need to be initiated to achieve appropriate capacity for scale-up and the production of affordable dosage forms.

Progresses and Prospects of Neuroprotective Agents-Loaded Nanoparticles and Biomimetic Material in Ischemic Stroke

Ischemic stroke remains the leading cause of death and disability, while the main mechanisms of dominant neurological damage in stroke contain excitotoxicity, oxidative stress, and inflammation. The clinical application of many neuroprotective agents is limited mainly due to their inability to cross the blood-brain barrier (BBB), short half-life and low bioavailability. These disadvantages can be better eliminated/reduced by nanoparticle as the carrier of these drugs. This review expounded the currently hot researched nanomedicines from the perspective of the mechanism of ischemic stroke. In addition, this review describes the bionic nanomedicine delivery strategies containing cells, cell membrane vesicles and exosomes that can effectively avoid the risk of clearance by the reticuloendothelial system. The potential challenges and application prospect for clinical translation of these delivery platforms were also discussed.

Oxidative Stress in Ischemia/Reperfusion Injuries following Acute Ischemic Stroke

Recanalization therapy is increasingly used in the treatment of acute ischemic stroke. However, in about one third of these patients, recanalization is followed by ischemia/reperfusion injuries, and clinically to worsening of the neurological status. Much research has focused on unraveling the involved mechanisms in order to prevent or efficiently treat these injuries. What we know so far is that oxidative stress and mitochondrial dysfunction are significantly involved in the pathogenesis of ischemia/reperfusion injury. However, despite promising results obtained in experimental research, clinical studies trying to interfere with the oxidative pathways have mostly failed. The current article discusses the main mechanisms leading to ischemia/reperfusion injuries, such as mitochondrial dysfunction, excitotoxicity, and oxidative stress, and reviews the clinical trials with antioxidant molecules highlighting recent developments and future strategies.

Antioxidant Therapy in Oxidative Stress-Induced Neurodegenerative Diseases: Role of Nanoparticle-Based Drug Delivery Systems in Clinical Translation

Free radicals are formed as a part of normal metabolic activities but are neutralized by the endogenous antioxidants present in cells/tissue, thus maintaining the redox balance. This redox balance is disrupted in certain neuropathophysiological conditions, causing oxidative stress, which is implicated in several progressive neurodegenerative diseases. Following neuronal injury, secondary injury progression is also caused by excessive production of free radicals. Highly reactive free radicals, mainly the reactive oxygen species (ROS) and reactive nitrogen species (RNS), damage the cell membrane, proteins, and DNA, which triggers a self-propagating inflammatory cascade of degenerative events. Dysfunctional mitochondria under oxidative stress conditions are considered a key mediator in progressive neurodegeneration. Exogenous delivery of antioxidants holds promise to alleviate oxidative stress to regain the redox balance. In this regard, natural and synthetic antioxidants have been evaluated. Despite promising results in preclinical studies, clinical translation of antioxidants as a therapy to treat neurodegenerative diseases remains elusive. The issues could be their low bioavailability, instability, limited transport to the target tissue, and/or poor antioxidant capacity, requiring repeated and high dosing, which cannot be administered to humans because of dose-limiting toxicity. Our laboratory is investigating nanoparticle-mediated delivery of antioxidant enzymes to address some of the above issues. Apart from being endogenous, the main advantage of antioxidant enzymes is their catalytic mechanism of action; hence, they are significantly more effective at lower doses in detoxifying the deleterious effects of free radicals than nonenzymatic antioxidants. This review provides a comprehensive analysis of the potential of antioxidant therapy, challenges in their clinical translation, and the role nanoparticles/drug delivery systems could play in addressing these challenges.

Dodging blood brain barrier with "nano" warriors: Novel strategy against ischemic stroke

Ischemic stroke (IS) is one of the leading causes of death and disability resulting in inevitable burden globally. Ischemic injury initiates cascade of pathological events comprising energy dwindling, failure of ionic gradients, failure of blood brain barrier (BBB), vasogenic edema, calcium over accumulation, excitotoxicity, increased oxidative stress, mitochondrial dysfunction, inflammation and eventually cell death. In spite of such complexity of the disease, the only treatment approved by US Food and Drug Administration (FDA) is tissue plasminogen activator (t-PA). This therapy overcome blood deficiency in the brain along with side effects of reperfusion which are responsible for considerable tissue injury. Therefore, there is urgent need of novel therapeutic perspectives that can protect the integrity of BBB and salvageable brain tissue. Advancement in nanomedicine is empowering new approaches that are potent to improve the understanding and treatment of the IS. Herein, we focus nanomaterial mediated drug delivery systems (DDSs) and their role to bypass and cross BBB especially via intranasal drug delivery. The various nanocarriers used in DDSs are also discussed. In a nut shell, the objective is to provide an overview of use of nanomedicine in the diagnosis and treatment of IS to facilitate the research from benchtop to bedside.

Nanomedicines, an emerging therapeutic regimen for treatment of ischemic cerebral stroke: A review

Owing to its intricate pathophysiology, cerebral stroke is a serious medical condition caused by interruption or obstruction of blood supply (blockage of vasculature) to the brain tissues which results in diminished supply of essential nutrients and oxygen (hypoxia) and ultimate necrosis of neuronal tissues. A prompt risks assessment and immediate rational therapeutic plan with proficient neuroprotection play critically important role in the effective management of this neuronal emergency. Various conventional medications are being used for treatment of acute ischemic cerebral stroke but fibrinolytic agents, alone or in combination with other agents are considered the mainstay. These clot-busting agents effectively restore blood supply (reperfusion) to ischemic regions of the brain; however, their clinical significance is hampered due to various factors such as short plasma half-life, limited distribution to brain tissues due to the presence of highly efficient physiological barrier, blood brain barrier (BBB), and lacking of target-specific delivery to the ischemic brain regions. To alleviate these issues, various types of nanomedicines such as polymeric nanoparticles (NPs), liposomes, nanoemulsion, micelles and dendrimers have been designed and evaluated. The implication of these newer therapies (nanomedicines) have revolutionized the therapeutic outcomes by improving the plasma half-life, permeation across BBB, efficient distribution to ischemic cerebral tissues and neuroprotection. Furthermore, the adaptation of some diverse techniques including PEGylation, tethering of targeting ligands on the surfaces of nanomedicines, and pH responsive features have also been pondered. The implication of these emerging adaptations have shown remarkable potential in maximizing the targeting efficiency of drugs to ischemic brain tissues, simultaneous delivery of drugs and imaging agents (for early prognosis as well as monitoring of therapy), and therapeutic outcomes such as long-term neuroprotection.

Anti-inflammatory efficacy of Berberine Nanomicelle for improvement of cerebral ischemia: formulation, characterization and evaluation in bilateral common carotid artery occlusion rat model

BACKGROUND

Berberine (BBR) is a plant alkaloid that possesses anti-inflammatory and anti-oxidant effects with low oral bioavailability. In this study, micelle formulation of BBR was investigated to improve therapeutic efficacy and examined its effect on the secretion of inflammatory cytokines in cerebral ischemia in the animal model.

MATERIAL AND METHODS

Nano formulation was prepared by thin-film hydration method, and characterized by particle size, zeta potential, morphology, encapsulation efficacy, and drug release in Simulated Gastric Fluid (SGF) and Simulated Intestine Fluid (SIF). Then, Wistar rats were pretreated with the drug (100 mg/kg) and nano-drug (25, 50, 75, 100 mg/kg) for 14 days. Then, on the fourteenth day, stroke induction was accomplished by Bilateral Common Carotid Artery Occlusion (BCCAO); after that, Tumor Necrosis Factor - Alpha (TNF-α), Interleukin - 1 Beta (IL-1ß), and Malondialdehyde (MDA) levels were measured in the supernatant of the whole brain, then the anti-inflammatory effect of BBR formulations was examined.

RESULT AND DISCUSSION

Micelles were successfully formed with appropriate characteristics and smaller sizes than 20 nm. The Poly Dispersity Index (PDI), zeta potential, encapsulation efficacy of micelles was 0.227, - 22 mV, 81%, respectively. Also, the stability of nano micelles was higher in SGF as compared to SIF. Our outcomes of TNF-a, IL-1B, and MDA evaluation show a significant ameliorating effect of the Berberine (BBR) and BBR-loaded micelles in pretreated groups.

CONCLUSION

Our experimental data show that pretreated groups in different doses (nano BBR 100, 75, 50 mg/kg, and BBR 100 mg/kg) successfully showed decreased levels of the inflammatory factors in cerebral ischemia compared with the stroke group and pretreated group with nano BBR in the dose of 25 mg/kg. Nano BBR formulation with a lower dose can be a better candidate than conventional BBR formulation to reduce oxidative and inflammatory factors in cerebral ischemia. Therefore, BBR-loaded micelle formulation could be a promising protective agent on cerebral ischemia.

Nanoparticles-mediated emerging approaches for effective treatment of ischemic stroke

Ischemic stroke leads to high disability and mortality. The limited delivery efficiency of most therapeutic substances is a major challenge for effective treatment of ischemic stroke. Inspired by the prominent merit of nanoscale particles in brain targeting and blood-brain barrier (BBB) penetration, various functional nanoparticles have been designed as promising drug delivery platforms that are expected to improve the therapeutic effect of ischemic stroke. Based on the complex pathological mechanisms of ischemic stroke, this review outline and summarize the rationally designed nanoparticles-mediated emerging approaches for effective treatment of ischemic stroke, including recanalization therapy, neuroprotection therapy, and combination therapy. On this bases, the potentials and challenges of nanoparticles in the treatment of ischemic stroke are revealed, and new thoughts and perspectives are proposed for the design of feasible nanoparticles for effective treatment of ischemic stroke.