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

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.

A perspective on therapies for amyotrophic lateral sclerosis: can disease progression be curbed?

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons, leading to paralysis and eventually death. Symptomatic treatments such as inhibition of salivation, alleviation of muscle cramps, and relief of spasticity and pain still play an important role in enhancing the quality of life. To date, riluzole and edaravone are the only two drugs approved by the Food and Drug Administration for the treatment of ALS in a few countries. While there is adequate consensus on the modest efficacy of riluzole, there are still open questions concerning the efficacy of edaravone in slowing the disease progression. Therefore, identification of novel therapeutic strategies is urgently needed. Impaired autophagic process plays a critical role in ALS pathogenesis. In this review, we focus on therapies modulating autophagy in the context of ALS. Furthermore, stem cell therapies, gene therapies, and newly-developed biomaterials have great potentials in alleviating neurodegeneration, which might halt the disease progression. In this review, we will summarize the current and prospective therapies for ALS.

Recent advances in nanomedicines for the treatment of ischemic stroke

Ischemic stroke is a cerebrovascular disease normally caused by interrupted blood supply to the brain. Ischemia would initiate the cascade reaction consisted of multiple biochemical events in the damaged areas of the brain, where the ischemic cascade eventually leads to cell death and brain infarction. Extensive researches focusing on different stages of the cascade reaction have been conducted with the aim of curing ischemic stroke. However, traditional treatment methods based on antithrombotic therapy and neuroprotective therapy are greatly limited for their poor safety and treatment efficacy. Nanomedicine provides new possibilities for treating stroke as they could improve the pharmacokinetic behavior of drugs in vivo, achieve effective drug accumulation at the target site, enhance the therapeutic effect and meanwhile reduce the side effect. In this review, we comprehensively describe the pathophysiology of stroke, traditional treatment strategies and emerging nanomedicines, summarize the barriers and methods for transporting nanomedicine to the lesions, and illustrate the latest progress of nanomedicine in treating ischemic stroke, with a view to providing a new feasible path for the treatment of cerebral ischemia.

Impact of edaravone on serum CXC chemokine ligand-13 levels and perioperative neurocognitive disorders in elderly patients with hip replacement

BACKGROUND

Perioperative neurocognitive disorders (PND) are a series of severe complications in the perioperative and anesthetic periods with a decline in memory, execution ability, and information processing speed as the primary clinical manifestation. This study aimed to evaluate the impact of edaravone (EDA) on PND and peripheral blood C-X-C motif chemokine ligand 13 (CXCL13) levels in elderly patients with hip replacement.

METHODS

A total of 160 elderly patients undergoing hip arthroplasty in Affiliated Dongguan People's Hospital of Southern Medical University (from March 2016 to March 2018) were randomly and double-blindly categorized into an EDA group and a control group (CON). Group EDA was administered intravenously EDA 30 min before surgery, and group CON was administered intravenously saline. The cognitive function of the two groups was evaluated 1-day before the operation and at 1 and 12 months after surgery, and the incidence of post-operative delirium was tested on days 1, 3, and 7 after surgery using the Chinese version of the confusion assessment method. Serum CXCL13 and interleukin (IL)-6 concentrations were measured before anesthesia, during surgery (30 min after skin incision), and on days 1, 3, and 7 after surgery. The continuous variables in accordance with normal distribution were tested using the Student's t test, the continuous variables without normal distribution using the Mann-Whitney U test, and categorical variables by the χ2 test or Fisher exact test.

RESULTS

The incidence of post-operative delirium within 7 days after surgery was significantly higher in group CON than that in group EDA (31.3% vs. 15.0%, t = -5.6, P < 0.001). The modified telephone interview for cognitive status and activities of daily life scores were significantly higher in the group EDA than those in the group CON at 1 month (39.63 ± 4.35 vs. 33.63 ± 5.81, t = -2.13, P < 0.05 and 74.3 ± 12.6 vs. 61.2 ± 13.1, t = -1.69, P < 0.05) and 12 months (40.13 ± 5.93 vs. 34.13 ± 5.36, t = -3.37, P < 0.05 and 79.6 ± 11.7 vs. 65.6 ± 16.6, t = -2.08, P < 0.05) after surgery; and the incidence of neurocognitive dysfunction was significantly lower in the group EDA than that in the group CON (P < 0.05). Serum CXCL13 and IL-6 concentrations were significantly lower in the group EDA than those in the group CON during and after surgery (P < 0.05).

CONCLUSION

EDA can significantly reduce the serum concentrations of CXCL13 and IL-6 and improve the PND of patients.

Preferential Targeting Cerebral Ischemic Lesions with Cancer Cell-Inspired Nanovehicle for Ischemic Stroke Treatment

The poor drug delivery to cerebral ischemic regions is a key challenge of ischemic stroke treatment. Inspired by the intriguing blood-brain barrier (BBB)-penetrating ability of 4T1 cancer cells upon their brain metastasis, we herein designed a promising biomimetic nanoplatform by camouflaging a succinobucol-loaded pH-sensitive polymeric nanovehicle with a 4T1 cell membrane (MPP/SCB), aiming to promote the preferential targeting of cerebral ischemic lesions to attenuate the ischemia/reperfusion injury. In transient middle cerebral artery occlusion (tMCAO) rat models, MPP/SCB could be preferentially delivered to the ischemic hemisphere with a 4.79-fold higher than that in the normal hemisphere. Moreover, MPP/SCB produced notable enhancement of microvascular reperfusion in the ischemic hemisphere, resulting in a 69.9% reduction of infarct volume and showing remarkable neuroprotective effects of tMCAO rats, which was superior to the counterpart uncamouflaged nanovehicles (PP/SCB). Therefore, this design provides a promising nanoplatform to target the cerebral ischemic lesions for ischemic stroke therapy.

The Role of Nanomaterials in Stroke Treatment: Targeting Oxidative Stress

Stroke has a high rate of morbidity and disability, which seriously endangers human health. In stroke, oxidative stress leads to further damage to the brain tissue. Therefore, treatment for oxidative stress is urgently needed. However, antioxidative drugs have demonstrated obvious protective effects in preclinical studies, but the clinical studies have not seen breakthroughs. Nanomaterials, with their characteristically small size, can be used to deliver drugs and have demonstrated excellent performance in treating various diseases. Additionally, some nanomaterials have shown potential in scavenging reactive oxygen species (ROS) in stroke according to the nature of nanomaterials. The drugs' delivery ability of nanomaterials has great significance for the clinical translation and application of antioxidants. It increases drug blood concentration and half-life and targets the ischemic brain to protect cells from oxidative stress-induced death. This review summarizes the characteristics and progress of nanomaterials in the application of antioxidant therapy in stroke, including ischemic stroke, hemorrhagic stroke, and neural regeneration. We also discuss the prospect of nanomaterials for the treatment of oxidative stress in stroke and the challenges in their application, such as the toxicity and the off-target effects of nanomaterials.

Towards precision nanomedicine for cerebrovascular diseases with emphasis on Cerebral Cavernous Malformation (CCM)

Introduction: Cerebrovascular diseases encompass various disorders of the brain vasculature, such as ischemic/hemorrhagic strokes, aneurysms, and vascular malformations, also affecting the central nervous system leading to a large variety of transient or permanent neurological disorders. They represent major causes of mortality and long-term disability worldwide, and some of them can be inherited, including Cerebral Cavernous Malformation (CCM), an autosomal dominant cerebrovascular disease linked to mutations in CCM1/KRIT1, CCM2, or CCM3/PDCD10 genes.Areas covered: Besides marked clinical and etiological heterogeneity, some commonalities are emerging among distinct cerebrovascular diseases, including key pathogenetic roles of oxidative stress and inflammation, which are increasingly recognized as major disease hallmarks and therapeutic targets. This review provides a comprehensive overview of the different clinical features and common pathogenetic determinants of cerebrovascular diseases, highlighting major challenges, including the pressing need for new diagnostic and therapeutic strategies, and focusing on emerging innovative features and promising benefits of nanomedicine strategies for early detection and targeted treatment of such diseases.Expert opinion: Specifically, we describe and discuss the multiple physico-chemical features and unique biological advantages of nanosystems, including nanodiagnostics, nanotherapeutics, and nanotheranostics, that may help improving diagnosis and treatment of cerebrovascular diseases and neurological comorbidities, with an emphasis on CCM disease.

A sphingosine kinase 2-mimicking TAT-peptide protects neurons against ischemia-reperfusion injury by activating BNIP3-mediated mitophagy

We have previously shown that sphingosine kinase 2 (SPK2) interacts with Bcl-2 via its BH3 domain, activating autophagy by inducing the dissociation of Beclin-1/Bcl-2 complexes, and that a TAT-SPK2 peptide containing the BH3 domain of SPK2 protects neurons against ischemic injury. The goals of the present study were to establish the functional significance of these findings, by testing whether TAT-SPK2 was effective in a mouse model of ischemic stroke, and to explore potential underlying mechanisms. Mice were administered with TAT-SPK2 by intraperitoneal injection before or after transient middle cerebral artery occlusion (tMCAO). Infarct volume, neurological deficit and brain water content were assessed 24 h after reperfusion. Mitophagy inhibitor Mdivi-1 and BNIP3 siRNAs were used to examine the involvement of BNIP3-dependent mitophagy in the neuroprotection of TAT-SPK2. Mitophagy was quantified by immunoblotting, immunofluorescence and electron microscopy. The interaction between TAT-SPK2 and Bcl-2, Bcl-2 and BNIP3 was detected by co-immunoprecipitation. In the tMCAO model, pre-treatment with TAT-SPK2 significantly reduced infarct volume, improved neurological function and decreased brain edema. Neuroprotection by TAT-SPK2 was still seen when the peptide was administered 3 h after reperfusion. TAT-SPK2 also significantly improved functional recovery and reduced long-term brain atrophy of the ischemic hemisphere 30 days after administration. Our studies further showed that TAT-SPK2 directly binds to Bcl-2 and disrupts Bcl-2/Beclin-1 or Bcl-2/BNIP3 complexes to induce mitophagy. These results suggest that TAT-SPK2 protects neurons against ischemia reperfusion injury by activating BNIP3-mediated mitophagy. Agents exploiting this molecular mechanism are potential candidates for the treatment of ischemic stroke.

Blood-Brain Barrier Modulation to Improve Glioma Drug Delivery

The blood-brain barrier (BBB) is formed by brain microvascular endothelial cells that are sealed by tight junctions, making it a significant obstacle for most brain therapeutics. The poor BBB penetration of newly developed therapeutics has therefore played a major role in limiting their clinical success. A particularly challenging therapeutic target is glioma, which is the most frequently occurring malignant brain tumor. Thus, to enhance therapeutic uptake in tumors, researchers have been developing strategies to modulate BBB permeability. However, most conventional BBB opening strategies are difficult to apply in the clinical setting due to their broad, non-specific modulation of the BBB, which can result in damage to normal brain tissue. In this review, we have summarized strategies that could potentially be used to selectively and efficiently modulate the tumor BBB for more effective glioma treatment.

Edaravone-Loaded Macrophage-Derived Exosomes Enhance Neuroprotection in the Rat Permanent Middle Cerebral Artery Occlusion Model of Stroke

Edaravone (Edv) can inhibit tissue damage, cause cerebral edema, and delay neuronal death caused by acute cerebral infarction. Exosomes are considered as cargo carriers for intercellular communication and serve as important regulators in many pathological processes. Here, we developed macrophage-derived exosomes (Exo) containing Edv (Exo + Edv) to improve the bioavailability of Edv and enhance the neuroprotective effects in a rat model of permanent middle cerebral artery occlusion (PMCAO). The results showed that Exo + Edv significantly improved the bioavailability of Edv and prolonged half-life (t_1/2). At the same time, Exo + Edv made Edv more easily reach the ischemic side of rats with PMCAO and was localized with neuronal cells and microglia, thus reducing the death of neuronal cells and promoting the polarization of microglia from M1 to M2. Taken together, Exo + Edv may become a potential clinical treatment option for PMCAO.

Stigmasterol alleviates cerebral ischemia/reperfusion injury by attenuating inflammation and improving antioxidant defenses in rats

BACKGROUND/AIMS

The paper aimed to investigate the effects of Stigmasterol on inflammatory factors, antioxidant capacity, and apoptotic signaling pathways in brain tissue of rats with cerebral ischemia/reperfusion (I/R) injury.

METHODS

The neurological deficits of the rats were analyzed and HE staining was performed. The cerebral infarct volume was calculated by means of TTC staining, and neuronal apoptosis was detected by TUNEL staining. At the same time, the contents of glutathione peroxidase, glutathione, superoxide dismutase (SOD), nitric oxide, and malondialdehyde in brain tissue were measured. The expression of the relevant protein was detected by means of Western blotting.

RESULTS

The results showed that the neurological deficit score and infarct area of the I/R rats in the soy sterol treatment group were significantly lower than those in the I/R group. Moreover, the levels of carbon monoxide and malondialdehyde in the soysterol group were significantly lower than those in the I/R group, and the expressions of cyclooxygenase-2 (Cox-2) and NF-κB (p65) in the soysterol group were also significantly lower than those in the I/R group. The expression of Nrf2 (nucleus) and heme oxygenase-1 (HO-1) increased significantly, and the activities of antioxidant enzymes and SOD were increased. In addition, the stigmasterol treatment can inhibit apoptosis, down-regulate Bax and cleaved caspase-3 expression, and up-regulate Bcl-Xl expression.

CONCLUSION

Stigmasterol protects the brain from brain I/R damage by reducing oxidative stress and inflammation.

Biomaterials to Neuroprotect the Stroke Brain: A Large Opportunity for Narrow Time Windows

Ischemic stroke represents one of the most prevalent pathologies in humans and is a leading cause of death and disability. Anti-thrombolytic therapy with tissue plasminogen activator (t-PA) and surgical thrombectomy are the primary treatments to recanalize occluded vessels and normalize the blood flow in ischemic and peri-ischemic regions. A large majority of stroke patients are refractory to treatment or are not eligible due to the narrow time window of therapeutic efficacy. In recent decades, we have significantly increased our knowledge of the molecular and cellular mechanisms that inexorably lead to progressive damage in infarcted and peri-lesional brain areas. As a result, promising neuroprotective targets have been identified and exploited in several stroke models. However, these considerable advances have been unsuccessful in clinical contexts. This lack of clinical translatability and the emerging use of biomaterials in different biomedical disciplines have contributed to developing a new class of biomaterial-based systems for the better control of drug delivery in cerebral disorders. These systems are based on specific polymer formulations structured in nanoparticles and hydrogels that can be administered through different routes and, in general, bring the concentrations of drugs to therapeutic levels for prolonged times. In this review, we first provide the general context of the molecular and cellular mechanisms impaired by cerebral ischemia, highlighting the role of excitotoxicity, inflammation, oxidative stress, and depolarization waves as the main pathways and targets to promote neuroprotection avoiding neuronal dysfunction. In the second part, we discuss the versatile role played by distinct biomaterials and formats to support the sustained administration of particular compounds to neuroprotect the cerebral tissue at risk of damage.

Advances in nanotechnology-based strategies for the treatments of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurodegenerative disease that affects both upper and lower motor neurons, which results in loss of muscle control and eventual paralysis [1]. Currently, there are as yet unresolved challenges regarding efficient drug delivery into the central nervous system (CNS). These challenges can be attributed to multiple factors including the presence of the blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), as well as the inherent characteristics of the drugs themselves (e.g. low solubility, insufficient bioavailability/bio-stability, 'off-target' effects) etc. As a result, conventional drug delivery systems may not facilitate adequate dosage of the required drugs for functional recovery in ALS patients. Nanotechnology-based strategies, however, employ engineered nanostructures that show great potential in delivering single or combined therapeutic agents to overcome the biological barriers, enhance interaction with targeted sites, improve drug bioavailability/bio-stability and achieve real-time tracking while minimizing the systemic side-effects. This review provides a concise discussion of recent advances in nanotechnology-based strategies in relation to combating specific pathophysiology relevant to ALS disease progression and investigates the future scope of using nanotechnology to develop innovative treatments for ALS patients.

Antioxidant Alternatives in the Treatment of Amyotrophic Lateral Sclerosis: A Comprehensive Review

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that produces a selective loss of the motor neurons of the spinal cord, brain stem and motor cortex. Oxidative stress (OS) associated with mitochondrial dysfunction and the deterioration of the electron transport chain has been shown to be a factor that contributes to neurodegeneration and plays a potential role in the pathogenesis of ALS. The regions of the central nervous system affected have high levels of reactive oxygen species (ROS) and reduced antioxidant defenses. Scientific studies propose treatment with antioxidants to combat the characteristic OS and the regeneration of nicotinamide adenine dinucleotide (NAD+) levels by the use of precursors. This review examines the possible roles of nicotinamide riboside and pterostilbene as therapeutic strategies in ALS.

Nanocarriers for Stroke Therapy: Advances and Obstacles in Translating Animal Studies

The technology of drug delivery systems (DDS) has expanded into many applications, such as for treating neurological disorders. Nanoparticle DDS offer a unique strategy for targeted transport and improved outcomes of therapeutics. Stroke is likely to benefit from the emergence of this technology though clinical breakthroughs are yet to manifest. This review explores the recent advances in this field and provides insight on the trends, prospects and challenges of translating this technology to clinical application. Carriers of diverse material compositions are presented, with special focus on the surface properties and emphasis on the similarities and inconsistencies among in vivo experimental paradigms. Research attention is scattered among various nanoparticle DDS and various routes of drug administration, which expresses the lack of consistency among studies. Analysis of current literature reveals lipid- and polymer-based DDS as forerunners of DDS for stroke; however, cell membrane-derived vesicles (CMVs) possess the competitive edge due to their innate biocompatibility and superior efficacy. Conversely, inorganic and carbon-based DDS offer different functionalities as well as varied capacity for loading but suffer mainly from poor safety and general lack of investigation in this area. This review supports the existing literature by systematizing presently available data and accounting for the differences in drugs of choice, carrier types, animal models, intervention strategies and outcome parameters.

Edaravone prevents memory impairment in an animal model of post-traumatic distress

Post-traumatic stress disorder (PTSD) is a mental health problem that develops in a proportion of individuals after experiencing a potential life-threatening traumatic stress event. Edaravone is a free radical scavenger, with a neuroprotective effect against cognitive impairment in several animal models. In the present study, the protective effect of edaravone on PTSD-induced memory impairment was investigated. Single prolonged stress was used as an animal model of PTSD, comprising 2 h of restrain, 20-min forced swimming, 15-min rest, and 1-2-min diethyl ether exposure. Concurrently, edaravone was given at a dose of 6 mg/kg/day, intraperitoneally, for 21 days. The radial arm water maze was used to assess learning and memory. Antioxidant biomarkers were measured in hippocampus tissues. Chronic administration of edaravone prevented impairment of short-term and long-term memory. Edaravone also prevented the stress-induced decrease in the ratio of reduced glutathione/oxidized glutathione and the activities of glutathione peroxidase and catalase enzymes in the hippocampus, as well as increases in the levels of oxidized glutathione and thiobarbituric acid reactive substances. In conclusion, edaravone ameliorated oxidative stress and cognitive impairment associated with a PTSD model, probably by supporting antioxidant mechanism in the hippocampus.

Edaravone combined with cinepazide maleate on neurocyte autophagy and neurological function in rats with subarachnoid hemorrhage

Effects of edaravone combined with cinepazide maleate on neurocyte autophagy and neurological function in rats with subarachnoid hemorrhage were investigated. Eighty SD rats were selected to establish subarachnoid hemorrhage (SAH) rat models, which were divided into sham operation group, SAH group, MCI group and combined group. Hippocampal tissue of each group was taken to observe the number of neurocytes. The expression levels of Beclin-1 and (light chain LC3)-II of rats in each group were detected by ELISA. Pearson's correlation factors were used to analyze the correlation between Beclin-1 and LC3-11, and neurological function tests were carried out on rats of each group 14 and 28 days after administration. The morphological and structural damage of nerve cells in the combined group was further alleviated, and the survival rate of neurons significantly increased at all time points (P<0.05). The expression levels of Beclin-1 and LC3-11 in combined group was significantly higher than those in SAH group and CMI group (P<0.05), and Beclin-1 was positively correlated with LC3-11 (r=0.9454). Longa score of the combined group was significantly lower than that of the other two groups, and muscle strength score was significantly higher than that of the other two groups (P<0.05). Edaravone combined with cinepazide maleate can effectively increase the survival rate of brain cells and promote the volatilization of neurological function in the treatment of hemorrhage in the subretinal space of the omentum, which is worthy of popularization and application.

Two Decades-Long Journey from Riluzole to Edaravone: Revisiting the Clinical Pharmacokinetics of the Only Two Amyotrophic Lateral Sclerosis Therapeutics

The recent approval of edaravone has provided an intravenous option to treat amyotrophic lateral sclerosis (ALS) in addition to the existing oral agent, riluzole. The present work was primarily undertaken to provide a comprehensive clinical pharmacokinetic summary of the two approved ALS therapeutics. The key objectives of the review were to (i) tabulate the clinical pharmacokinetics of riluzole and edaravone with emphasis on absorption, distribution, metabolism and excretion (ADME) properties; (ii) provide a comparative scenario of the pharmacokinetics of the two drugs wherever possible; and (iii) provide perspectives and introspection on the gathered clinical pharmacokinetic data of the two drugs with appropriate conjectures to quench scientific curiosity. Based on this review, the following key highlights were deduced: (i) as a result of both presystemic metabolism and polymorphic hepatic cytochrome P450 (CYP) metabolism, the oral drug riluzole exhibited more inter-subject variability than that of intravenous edaravone; (ii) using various parameters for comparison, including the published intravenous data for riluzole, it was apparent that edaravone was achieving the desired systemic concentrations to possibly drive the local brain concentrations for its efficacy in ALS patients with lesser variability than riluzole; (iii) using scientific conjectures, it was deduced that the availability of intravenous riluzole may not be beneficial in therapy due to its fast systemic clearance; (iv) on the contrary, however, there appeared to be an opportunity for the development of an oral dosage form of edaravone, which may potentially benefit the therapy option for ALS patients by avoiding hospitalization costs; and (v) because of the existence of pharmaco-resistance for the brain entry in ALS patients, it appeared prudent to consider combination strategies of edaravone and/or riluzole with suitable P-glycoprotein efflux-blocking drugs to gain more favorable outcomes in ALS patients.

Nanomaterial-based blood-brain-barrier (BBB) crossing strategies

Increasing attention has been paid to the diseases of central nervous system (CNS). The penetration efficiency of most CNS drugs into the brain parenchyma is rather limited due to the existence of blood-brain barrier (BBB). Thus, BBB crossing for drug delivery to CNS remains a significant challenge in the development of neurological therapeutics. Because of the advantageous properties (e.g., relatively high drug loading content, controllable drug release, excellent passive and active targeting, good stability, biodegradability, biocompatibility, and low toxicity), nanomaterials with BBB-crossability have been widely developed for the treatment of CNS diseases. This review summarizes the current understanding of the physiological structure of BBB, and provides various nanomaterial-based BBB-crossing strategies for brain delivery of theranostic agents, including intranasal delivery, temporary disruption of BBB, local delivery, cell penetrating peptide (CPP) mediated BBB-crossing, receptor mediated BBB-crossing, shuttle peptide mediated BBB-crossing, and cells mediated BBB-crossing. Clinicians, biologists, material scientists and chemists are expected to be interested in this review.

The Potential of Biomaterial-Based Approaches as Therapies for Ischemic Stroke: A Systematic Review and Meta-Analysis of Pre-clinical Studies

Background: In recent years pre-clinical stroke research has shown increased interest in the development of biomaterial-based therapies to promote tissue repair and functional recovery. Such strategies utilize biomaterials as structural support for tissue regeneration or as delivery vehicles for therapeutic agents. While a range of biomaterials have been tested in stroke models, currently no overview is available for evaluating the benefit of these approaches. We therefore performed a systematic review and meta-analysis of studies investigating the use of biomaterials for the treatment of stroke in experimental animal models. Methods: Studies were identified by searching electronic databases (PubMed, Web of Science) and reference lists of relevant review articles. Studies reporting lesion volume and/or neurological score were included. Standardized mean difference (SMD) and 95% confidence intervals were calculated using DerSimonian and Laird random effects. Study quality and risk of bias was assessed using the CAMARADES checklist. Publication bias was visualized by funnel plots followed by trim and fill analysis of missing publications. Results: A total of 66 publications were included in the systematic review, of which 44 (86 comparisons) were assessed in the meta-analysis. Overall, biomaterial-based interventions improved both lesion volume (SMD: -2.98, 95% CI: -3.48, -2.48) and neurological score (SMD: -2.3, 95% CI: -2.85, -1.76). The median score on the CAMARADES checklist was 5.5/10 (IQR 4.25-6). Funnel plots of lesion volume and neurological score data revealed pronounced asymmetry and publication bias. Additionally, trim and fill analysis estimated 19 "missing" studies for the lesion volume outcome adjusting the effect size to -1.91 (95% CI: -2.44, -1.38). Conclusions: Biomaterials including scaffolds and particles exerted a positive effect on histological and neurological outcomes in pre-clinical stroke models. However, heterogeneity in the field, publication bias and study quality scores which may be another source of bias call for standardization of outcome measures and improved study reporting.

Preparation, In Vivo and In Vitro Release of Polyethylene Glycol Monomethyl Ether-Polymandelic Acid Microspheres Loaded Panax Notoginseng Saponins

In order to enrich the types of Panax notoginseng saponins (PNS) sustained-release preparations and provide a new research idea for the research and development of traditional Chinese medicine sustained-release formulations, a series of Panax notoginseng saponins microspheres was prepared by a double emulsion method using a series of degradable amphiphilic macromolecule materials polyethylene glycol monomethyl ether-polymandelic acid (mPEG-PMA) as carrier. The structure and molecular weight of the series of mPEG-PMA were determined by nuclear magnetic resonance spectroscopy (1 HNMR) and gel chromatography (GPC). The results of the appearance, particle size, drug loading and encapsulation efficiency of the drug-loaded microspheres show that the mPEG10000-PMA (1:9) material is more suitable as a carrier for loading the total saponins of Panax notoginseng. The particle size was 2.51 ± 0.21 μm, the drug loading and encapsulation efficiency were 8.54 ± 0.16% and 47.25 ± 1.64%, respectively. The drug-loaded microspheres were used for in vitro release and degradation experiments to investigate the degradation and sustained release behaviour of the drug-loaded microspheres. The biocompatibility of the microspheres was studied by haemolytic, anticoagulant and cytotoxicity experiments. The pharmacological activity of the microspheres was studied by anti-inflammatory and anti-tumour experiments. The results showed that the drug-loaded microspheres could be released stably for about 12 days and degraded within 60 days. At the same time, the microspheres had good biocompatibility, anti-inflammatory and anti-tumour activities.

Edaravone inhibits autophagy after neuronal oxygen-glucose deprivation/recovery injury

PURPOSE OF THE STUDY

Edaravone is an oxygen free radical scavenger that is widely used to treat ischemic injury to the nervous system. This study investigated the effect of edaravone pretreatment on neurons subjected to oxygen-glucose deprivation/recovery (OGD/R) injury.

MATERIALS AND METHODS

Common neurons were subjected to oxygen and glucose deprivation for 1 h, followed by oxygen and glucose recovery for 0.5, 2, 6 and 12 h to establish the OGD/R model. Autophagy was assessed by electron microscope observation of autophagosomes, cell immunofluorescence, mRFP-GFP-LC3 virus cell fluorescence and western blotting analyses of the autophagy-related proteins. The findings showed that at OGD/R 2 h autophagy was high. Next, neurons were pretreated with different concentrations of edaravone (0, 5, 10, 25, 50 and 100 μM) before establishing the OGD/R model. Western blotting was used to analyze the expression of autophagy-related proteins. The CCK-8 assay was used to analyze cell viability after pretreatment with different concentrations of edaravone. Optimal inhibition of autophagy was achieved with the concentration of edaravone 50 μM. Neurons pretreated with 50 μM edaravone and established OGD/R model were analyzed for autophagy levels.

RESULTS

At every OGD/R time point autophagy was lower in neurons pretreated with edaravone than in those not pretreated with the drug. The difference was statistically significant without OGD/R 12 h.

CONCLUSIONS

Pretreatment with edaravone may reduce the level of autophagy in neurons subjected to OGD/R injury.

Platelet bio-nanobubbles as microvascular recanalization nanoformulation for acute ischemic stroke lesion theranostics

Since the expected therapeutic results of ischemic stroke are strictly time dependent, early and accurate diagnosis as well as short intervals between diagnosis and treatment are key factors for the survival of stroke patients. In this study, we fabricated platelet (PLT) membrane-derived biomimetic nanobubbles (PNBs) for timely perfusion intervention and ultrasound imaging of acute ischemic stroke. Methods: The PNBs are fabricated by sonication-assisted reassembly of repeatedly freeze-thawed live platelet-derived PLT membrane vesicles (PMVs). The TEM, SEM, EDS and DLS were used to analyze the morphology and physicochemical properties of PNBs. The HPLC and LC-MS/MS were applied to confirm the lipid and protein compositions of PNBs. The in vitro macrophage uptake and platelet aggregation of PNBs were designed to examine the immune escape and thrombotic response characteristics. Furthermore, based on a photothrombotic ischemic stroke mouse model, the biodistribution, stroke microvascular network change, as well as cerebral blood flow of PNBs were studied by using near-infrared fluorescence imaging, multimodal optical imaging, and full-field laser perfusion imager. Finally, we assessed the brain ultrasound imaging of PNBs with a high-resolution micro-imaging system using both B-mode and contrast mode. Results: The natural lipid and protein components isolated from PLT membrane endow the PNBs with accurate lesion-targeting ability. The preferentially accumulated PNBs exhibit microvascular bio-remodeling ability of the stroke lesion, which is critical for recanalization of the obstructed vessels to protect the neural cells around the ischemic region of the stroke. Furthermore, with the increased accumulation of PNBs clusters in the lesion, PNBs in the lesion can be monitored by real-time contrast-enhanced ultrasound imaging to indicate the severity and dynamic development of the stroke. Conclusions: In summary, platelet membrane-based nanobubbles for targeting acute ischemic lesions were developed as microvascular recanalization nanoformulation for acute ischemic stroke lesion theranostics. This biomimetic PNBs theranostic strategy will be valuable for ischemic stroke patients in the future.

Image-guided chemotherapy with specifically tuned blood brain barrier permeability in glioma margins

Blood-brain barrier (BBB) disruption is frequently observed in the glioma region. However, the tumor uptake of drugs is still too low to meet the threshold of therapeutic purpose.

Method: A tumor vasculature-targeted nanoagonist was developed. Glioma targeting specificity of the nanoagonist was evaluated by in vivo optical imaging. BBB permeability at the glioma margin was quantitatively measured by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). Single-photon emission computed tomography imaging/computed tomography (SPECT/CT) quantitatively determined the glioma uptake of the radiolabeled model drug. T2-weighted MRI monitored the tumor volume.

Results: Immunostaining studies demonstrated that the BBB remained partially intact in the invasive margin of patients' gliomas regardless of their malignancies. DCE-MRI showed that vascular permeability in the glioma margin reached its maximum at 45 min post nanoagonist administration. In vivo optical imaging indicated the high glioma targeting specificity of the nanoagonist. SPECT/CT showed the significantly enhanced glioma uptake of the model drug after pre-treatment with the nanoagonist. Image-guided paclitaxel injection after nanoagonist-mediated BBB modulation more efficiently attenuated tumor growth and extended survival than in animal models treated with paclitaxel or temozolomide alone.

Conclusion: Thus, image-guided drug delivery following BBB permeability modulation holds promise to enhance the efficacy of chemotherapeutics to glioma.

Poly(Ethylene Glycol)-Polylactide Micelles for Cancer Therapy

For the treatment of malignancy, many therapeutic agents, including small molecules, photosensitizers, immunomodulators, proteins and genes, and so forth, have been loaded into nanocarriers for controllable cancer therapy. Among these nanocarriers, polymeric micelles have been considered as one of the most promising nanocarriers, some of which have already been applied in different stages of clinical trials. The successful advantages of polymeric micelles from bench to bedside are due to their special core/shell structures, which can carry specific drugs in certain disease conditions. Particularly, poly(ethylene glycol)–polylactide (PEG–PLA) micelles have been considered as one of the most promising platforms for drug delivery. The PEG shell effectively prevents the adsorption of proteins and phagocytes, thereby evidently extending the blood circulation period. Meanwhile, the hydrophobic PLA core can effectively encapsulate many therapeutic agents. This review summarizes recent advances in PEG–PLA micelles for the treatment of malignancy. In addition, future perspectives for the development of PEG–PLA micelles as drug delivery systems are also presented.