Nanoparticle Formulations of Antioxidants for the Management of Oxidative Stress in Stroke: A Review

Res@LDH: A Novel Nanohybrid Therapeutic for Ischemia-Reperfusion Injury with Dual Reactive Oxygen Species Scavenging Efficiency

Ischemic stroke poses a global health challenge, necessitating effective therapeutic interventions given the limited time window for thrombolytic therapy. Here, we present Res@LDH, a novel nanohybrid therapeutic agent boasting a dual reactive oxygen species scavenging efficiency of approximately 90%. Comprising Ge-containing layered double hydroxide nanosheets (Ge-LDH) as a drug nanocarrier and resveratrol as a neuroprotective agent, Res@LDH demonstrates enhanced permeability across the blood-brain barrier, ensuring high biocompatibility and stability. We explored the potential of Res@LDH in mitigating oxidative stress injury induced by middle cerebral artery occlusion and reperfusion in mice, as well as H2O2-induced cytotoxicity in HT22 cells. Our experiments unveil Res@LDH's capacity to ameliorate neurological deficits, reduce the infarction volume, mitigate blood-brain barrier disruption, exhibit a robust antioxidant activity, and dampen the release of proinflammatory cytokines. Moreover, Res@LDH treatment markedly attenuates microglial and astrocytic activation. Leveraging a pioneering synthetic approach harnessing Ge-LDH and resveratrol, Res@LDH emerges as a promising strategy for addressing ischemia-reperfusion injury, offering a concise solution to current therapeutic challenges.

Cerium oxide nanoparticles (nanoceria) pretreatment attenuates cell death in the hippocampus and cognitive dysfunction due to repeated isoflurane anesthesia in newborn rats

General anesthetics exposure, particularly prolonged or repeated exposure, is a crucial cause of neurological injuries. Notably, isoflurane (ISO), used in pediatric anesthesia practice, is toxic to the developing brain. The relatively weak antioxidant system at early ages needs antioxidant support to protect the brain against anesthesia. Cerium oxide nanoparticles (CeO2-NPs, nanoceria) are nano-antioxidants and stand out due to their unique surface chemistry, high stability, and biocompatibility. Although CeO2-NPs have been shown to exhibit neuroprotective and cognitive function-facilitating effects, there are no reports on their protective effects against anesthesia-induced neurotoxicity and cognitive impairments. Herein, Wistar albino rat pups were exposed to ISO (1.5 %, 3-h) at postnatal day (P)7+P9+P11, and the protective properties of CeO2-NP pretreatment (0.5 mg/kg, intraperitoneal route) were investigated for the first time. The control group at P7+9+11 received 50 % O2 (3-h) instead of ISO. Exposure to nanoceria one-hour before ISO protected hippocampal neurons of the developing rat brain against apoptosis [determined by hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) analysis with caspase-3, and immunoblotting with Bax/Bcl2, cleaved caspase-3 and PARP1] oxidative stress, and inflammation [determined by immunoblotting with 4-hydroxynonenal (4HNE), nuclear factor kappa-B (NF-κB), and tumor necrosis factor-alpha (TNF-α)]. CeO2-NP pretreatment also reduced ISO-induced learning (at P28-32) and memory (at P33) deficits evaluated by Morris Water Maze. However, memory deficits and thigmotactic behaviors were detected in the agent-control group; elimination of these harmful effects will be possible with dose studies, thus providing evidence supporting safer use. Overall, our findings support pretreatment with nanoceria application as a simple strategy that might be used for pediatric anesthesia practice to protect infants and children from ISO-induced cell death and learning and memory deficits.

Utilizing reactive oxygen species-scavenging nanoparticles for targeting oxidative stress in the treatment of ischemic stroke: A review

Ischemic stroke, which accounts for the majority of stroke cases, triggers a complex series of pathophysiological events, prominently characterized by acute oxidative stress due to excessive production of reactive oxygen species (ROS). Oxidative stress plays a crucial role in driving cell death and inflammation in ischemic stroke, making it a significant target for therapeutic intervention. Nanomedicine presents an innovative approach to directly mitigate oxidative damage. This review consolidates existing knowledge on the role of oxidative stress in ischemic stroke and assesses the potential of various ROS-scavenging nanoparticles (NPs) as therapeutic agents. We explore the properties and mechanisms of metal, metal-oxide, and carbon-based NPs, emphasizing their catalytic activity and biocompatibility in scavenging free radicals and facilitating the delivery of therapeutic agents across the blood-brain barrier. Additionally, we address the challenges such as cytotoxicity, immunogenicity, and biodistribution that need to be overcome to translate these nanotechnologies from bench to bedside. The future of NP-based therapies for ischemic stroke holds promise, with the potential to enhance outcomes through targeted modulation of oxidative stress.

Reactive Oxygen Species-Responsive Chitosan-Bilirubin Nanoparticles Loaded with Statin for Treatment of Cerebral Ischemia

Cerebral ischemia impairs blood circulation, leading to elevated reactive oxygen species (ROS) production. A ROS-responsive delivery of drugs can enhance the therapeutic efficacy and minimize the side effects. There is insufficient evidence on the impact of ROS-responsive nanoparticles on ischemic stroke. We developed ROS-responsive chitosan-bilirubin (ChiBil) nanoparticles to target acute ischemic lesions and investigated the effect of atorvastatin-loaded ROS-responsive ChiBil. We randomly assigned rats with transient middle cerebral artery occlusion (MCAO) to 4 groups: saline, Statin, ChiBil, and ChiBil-Statin. These groups were treated daily via the tail vein for 7 d. Behavioral assessment, magnetic resonance (MR) imaging, evaluation of neuroinflammation, blood-brain barrier (BBB) integrity, apoptosis, and neurogenesis after stroke were conducted. In vitro, results showed nanoparticle uptake and reduced intracellular ROS, lipid peroxidation, and inflammatory cytokines (IL-6 and TNF-α). In vivo, results showed improved motor deficits and decreased infarct volumes on MR images in the ChiBil-Statin group compared with the Control group on day 7 (P < 0.05). Furthermore, the expression of inflammatory cytokines such as IL-1β and IL-6 was reduced in the ChiBil-Statin group compared with the Control group (P < 0.05). Improvements in BBB integrity, apoptosis, and neurogenesis were observed in the ChiBil-Statin group. The findings demonstrated that intravenous ROS-responsive multifunctional ChiBil-Statin could effectively deliver drugs to the ischemic brain, exerting marked synergistic pleiotropic neuroprotective effects. Therefore, ChiBil-Statin holds promise as a targeted therapy for ischemic vascular diseases characterized by increased ROS production, leading to new avenues for future research and potential clinical applications.

The Influence of Oxidative Stress Markers in Patients with Ischemic Stroke

Stroke is the second leading cause of death worldwide, and its incidence is rising rapidly. Acute ischemic stroke is a subtype of stroke that accounts for the majority of stroke cases and has a high mortality rate. An effective treatment for stroke is to minimize damage to the brain's neural tissue by restoring blood flow to decreased perfusion areas of the brain. Many reports have concluded that both oxidative stress and excitotoxicity are the main pathological processes associated with ischemic stroke. Current measures to protect the brain against serious damage caused by stroke are insufficient. For this reason, it is important to investigate oxidative and antioxidant strategies to reduce oxidative damage. This review focuses on studies assessing the concentration of oxidative stress biomarkers and the level of antioxidants (enzymatic and non-enzymatic) and their impact on the clinical prognosis of patients after stroke. Mechanisms related to the production of ROS/RNS and the role of oxidative stress in the pathogenesis of ischemic stroke are presented, as well as new therapeutic strategies aimed at reducing the effects of ischemia and reperfusion.

Advancing stroke therapy: the potential of MOF-based nanozymes in biomedical applications

In this study, we explored the growing use of metal-organic framework (MOF)-based Nanozymes in biomedical research, with a specific emphasis on their applications in stroke therapy. We have discussed the complex nature of stroke pathophysiology, highlighting the crucial role of reactive oxygen species (ROS), and acknowledging the limitations of natural enzymes in addressing these challenges. We have also discussed the role of nanozymes, particularly those based on MOFs, their structural similarities to natural enzymes, and their potential to improve reactivity in various biomedical applications. The categorization of MOF nanozymes based on enzyme-mimicking activities is discussed, and their applications in stroke therapy are explored. We have reported the potential of MOF in treating stroke by regulating ROS levels, alleviation inflammation, and reducing neuron apoptosis. Additionally, we have addressed the challenges in developing efficient antioxidant nanozyme systems for stroke treatment. The review concludes with the promise of addressing these challenges and highlights the promising future of MOF nanozymes in diverse medical applications, particularly in the field of stroke treatment.

Advanced Nano-Drug Delivery Systems in the Treatment of Ischemic Stroke

In recent years, the frequency of strokes has been on the rise year by year and has become the second leading cause of death around the world, which is characterized by a high mortality rate, high recurrence rate, and high disability rate. Ischemic strokes account for a large percentage of strokes. A reperfusion injury in ischemic strokes is a complex cascade of oxidative stress, neuroinflammation, immune infiltration, and mitochondrial damage. Conventional treatments are ineffective, and the presence of the blood-brain barrier (BBB) leads to inefficient drug delivery utilization, so researchers are turning their attention to nano-drug delivery systems. Functionalized nano-drug delivery systems have been widely studied and applied to the study of cerebral ischemic diseases due to their favorable biocompatibility, high efficiency, strong specificity, and specific targeting ability. In this paper, we briefly describe the pathological process of reperfusion injuries in strokes and focus on the therapeutic research progress of nano-drug delivery systems in ischemic strokes, aiming to provide certain references to understand the progress of research on nano-drug delivery systems (NDDSs).

Gold Nanoparticles in Neurological Diseases: A Review of Neuroprotection

This review explores the diverse applications of gold nanoparticles (AuNPs) in neurological diseases, with a specific focus on Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The introduction highlights the pivotal role of neuroinflammation in these disorders and introduces the unique properties of AuNPs. The review's core examines the mechanisms by which AuNPs exert neuroprotection and anti-neuro-inflammatory effects, elucidating various pathways through which they manifest these properties. The potential therapeutic applications of AuNPs in AD are discussed, shedding light on promising avenues for therapy. This review also explores the prospects of utilizing AuNPs in PD interventions, presenting a hopeful outlook for future treatments. Additionally, the review delves into the potential of AuNPs in providing neuroprotection after strokes, emphasizing their significance in mitigating cerebrovascular accidents' aftermath. Experimental findings from cellular and animal models are consolidated to provide a comprehensive overview of AuNPs' effectiveness, offering insights into their impact at both the cellular and in vivo levels. This review enhances our understanding of AuNPs' applications in neurological diseases and lays the groundwork for innovative therapeutic strategies in neurology.