Neuronal mitochondria-targeted therapy for Alzheimer's disease by systemic delivery of resveratrol using dual-modified novel biomimetic nanosystems

Advances in cell membrane-based biomimetic nanodelivery systems for natural products

Active components of natural products, which include paclitaxel, curcumin, gambogic acid, resveratrol, triptolide and celastrol, have promising anti-inflammatory, antitumor, anti-oxidant, and other pharmacological activities. However, their clinical application is limited due to low solubility, instability, low bioavailability, rapid metabolism, short half-life, and strong off-target toxicity. To overcome these drawbacks, cell membrane-based biomimetic nanosystems have emerged that avoid clearance by the immune system, enhance targeting, and prolong drug circulation, while also improving drug solubility and bioavailability, enhancing drug efficacy, and reducing side effects. This review summarizes recent advances in the preparation and coating of cell membrane-coated biomimetic nanosystems and in their applications to disease for targeted natural products delivery. Current challenges, limitations, and prospects in this field are also discussed, providing a research basis for the development of multifunctional biomimetic nanosystems for natural products.

To see or not to see: In vivo nanocarrier detection methods in the brain and their challenges

Nanoparticles have a great potential to significantly improve the delivery of therapeutics to the brain and may also be equipped with properties to investigate brain function. The brain, being a highly complex organ shielded by selective barriers, requires its own specialized detection system. However, a significant hurdle to achieve these goals is still the identification of individual nanoparticles within the brain with sufficient cellular, subcellular, and temporal resolution. This review aims to provide a comprehensive summary of the current knowledge on detection systems for tracking nanoparticles across the blood-brain barrier and within the brain. We discuss commonly employed in vivo and ex vivo nanoparticle identification and quantification methods, as well as various imaging modalities able to detect nanoparticles in the brain. Advantages and weaknesses of these modalities as well as the biological factors that must be considered when interpreting results obtained through nanotechnologies are summarized. Finally, we critically evaluate the prevailing limitations of existing technologies and explore potential solutions.

Bio-Nano Toolbox for Precision Alzheimer's Disease Gene Therapy

Alzheimer's disease (AD) is the most burdensome aging-associated neurodegenerative disorder, and its treatment encounters numerous failures during drug development. Although there are newly approved in-market β-amyloid targeting antibody solutions, pathological heterogeneity among patient populations still challenges the treatment outcome. Emerging advances in gene therapies offer opportunities for more precise personalized medicine; while, major obstacles including the pathological heterogeneity among patient populations, the puzzled mechanism for druggable target development, and the precision delivery of functional therapeutic elements across the blood-brain barrier remain and limit the use of gene therapy for central neuronal diseases. Aiming for "precision delivery" challenges, nanomedicine provides versatile platforms that may overcome the targeted delivery challenges for AD gene therapy. In this perspective, to picture a toolbox for AD gene therapy strategy development, the most recent advances from benchtop to clinics are highlighted, possibly available gene therapy targets, tools, and delivery platforms are outlined, their challenges as well as rational design elements are addressed, and perspectives in this promising research field are discussed.

Reactive oxygen species-scavenging nanomaterials for the prevention and treatment of age-related diseases

With increasing proportion of the elderly in the population, age-related diseases (ARD) lead to a considerable healthcare burden to society. Prevention and treatment of ARD can decrease the negative impact of aging and the burden of disease. The aging rate is closely associated with the production of high levels of reactive oxygen species (ROS). ROS-mediated oxidative stress in aging triggers aging-related changes through lipid peroxidation, protein oxidation, and DNA oxidation. Antioxidants can control autoxidation by scavenging free radicals or inhibiting their formation, thereby reducing oxidative stress. Benefiting from significant advances in nanotechnology, a large number of nanomaterials with ROS-scavenging capabilities have been developed. ROS-scavenging nanomaterials can be divided into two categories: nanomaterials as carriers for delivering ROS-scavenging drugs, and nanomaterials themselves with ROS-scavenging activity. This study summarizes the current advances in ROS-scavenging nanomaterials for prevention and treatment of ARD, highlights the potential mechanisms of the nanomaterials used and discusses the challenges and prospects for their applications.

A Membrane-Targeting Aggregation-Induced Emission Probe for Monitoring Lipid Droplet Dynamics in Ischemia/Reperfusion-Induced Cardiomyocyte Ferroptosis

Myocardial ischemia/reperfusion injury (MIRI) is the leading cause of irreversible myocardial damage. A pivotal pathogenic factor is ischemia/reperfusion (I/R)-induced cardiomyocyte ferroptosis, marked by iron overload and lipid peroxidation. However, the impact of lipid droplet (LD) changes on I/R-induced cardiomyocyte ferroptosis is unclear. In this study, an aggregation-induced emission probe, TPABTBP is developed that is used for imaging dynamic changes in LD during myocardial I/R-induced ferroptosis. TPABTBP exhibits excellent LD-specificity, superior capability for monitoring lipophagy, and remarkable photostability. Molecular dynamics (MD) simulation and super-resolution fluorescence imaging demonstrate that the TPABTBP is specifically localized to the phospholipid monolayer membrane of LDs. Imaging LDs in cardiomyocytes and myocardial tissue in model mice with MIRI reveals that the LD accumulation level increase in the early reperfusion stage (0-9 h) but decrease in the late reperfusion stage (>24 h) via lipophagy. The inhibition of LD breakdown significantly reduces the lipid peroxidation level in cardiomyocytes. Furthermore, it is demonstrated that chloroquine (CQ), an FDA-approved autophagy modulator, can inhibit ferroptosis, thereby attenuating MIRI in mice. This study describes the dynamic changes in LD during myocardial ischemia injury and suggests a potential therapeutic target for early MIRI intervention.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

Revitalizing Ancient Mitochondria with Nano-Strategies: Mitochondria-Remedying Nanodrugs Concentrate on Disease Control

Mitochondria, widely known as the energy factories of eukaryotic cells, have a myriad of vital functions across diverse cellular processes. Dysfunctions within mitochondria serve as catalysts for various diseases, prompting widespread cellular demise. Mounting research on remedying damaged mitochondria indicates that mitochondria constitute a valuable target for therapeutic intervention against diseases. But the less clinical practice and lower recovery rate imply the limitation of traditional drugs, which need a further breakthrough. Nanotechnology has approached favorable regiospecific biodistribution and high efficacy by capitalizing on excellent nanomaterials and targeting drug delivery. Mitochondria-remedying nanodrugs have achieved ideal therapeutic effects. This review elucidates the significance of mitochondria in various cells and organs, while also compiling mortality data for related diseases. Correspondingly, nanodrug-mediate therapeutic strategies and applicable mitochondria-remedying nanodrugs in disease are detailed, with a full understanding of the roles of mitochondria dysfunction and the advantages of nanodrugs. In addition, the future challenges and directions are widely discussed. In conclusion, this review provides comprehensive insights into the design and development of mitochondria-remedying nanodrugs, aiming to help scientists who desire to extend their research fields and engage in this interdisciplinary subject.

Cell Membrane Camouflaged Biomimetic Nanoparticles as a Versatile Platform for Brain Diseases Treatment

Although there are various advancements in biomedical in the past few decades, there are still challenges in the treatment of brain diseases. The main difficulties are the inability to deliver a therapeutic dose of the drug to the brain through the blood-brain barrier (BBB) and the serious side effects of the drug. Thus, it is essential to select biocompatible drug carriers and novel therapeutic tools to better enhance the effect of brain disease treatment. In recent years, biomimetic nanoparticles (BNPs) based on natural cell membranes, which have excellent biocompatibility and low immunogenicity, are widely used in the treatment of brain diseases to enable the drug to successfully cross the BBB and target brain lesions. BNPs can prolong the circulation time in vivo, are more conducive to drug aggregation in brain lesions. Cell membranes (CMs) from cancer cells (CCs), red blood cells (RBCs), white blood cells (WBCs), and so on are used as biomimetic coatings for nanoparticles (NPs) to achieve the ability to target, evade clearance, or stimulate the immune system. This review summarizes the application of different cell sources as BNPs coatings in the treatment of brain diseases and discusses the possibilities and challenges of clinical translation.

Resveratrol Activates Antioxidant Protective Mechanisms in Cellular Models of Alzheimer's Disease Inflammation

Resveratrol is a natural phenolic compound with known benefits against neurodegeneration. We analyzed in vitro the protective mechanisms of resveratrol against the proinflammatory monomeric C-reactive protein (mCRP). mCRP increases the risk of AD after stroke and we previously demonstrated that intracerebral mCRP induces AD-like dementia in mice. Here, we used BV2 microglia treated with mCRP for 24 h in the presence or absence of resveratrol. Cells and conditioned media were collected for analysis. Lipopolysaccharide (LPS) has also been implicated in AD progression and so LPS was used as a resveratrol-sensitive reference agent. mCRP at the concentration of 50 µg/mL activated the nitric oxide pathway and the NLRP3 inflammasome pathway. Furthermore, mCRP induced cyclooxygenase-2 and the release of proinflammatory cytokines. Resveratrol effectively inhibited these changes and increased the expression of the antioxidant enzyme genes Cat and Sod2. As central mechanisms of defense, resveratrol activated the hub genes Sirt1 and Nfe2l2 and inhibited the nuclear translocation of the signal transducer NF-ĸB. Proinflammatory changes induced by mCRP in primary mixed glial cultures were also protected by resveratrol. This work provides a mechanistic insight into the protective benefits of resveratrol in preventing the risk of AD induced by proinflammatory agents.

Exploring Chinese herbal medicine for ischemic stroke: insights into microglia and signaling pathways

Ischemic stroke is a prevalent clinical condition affecting the central nervous system, characterized by a high mortality and disability rate. Its incidence is progressively rising, particularly among younger individuals, posing a significant threat to human well-being. The activation and polarization of microglia, leading to pro-inflammatory and anti-inflammatory responses, are widely recognized as pivotal factors in the pathogenesis of cerebral ischemia and reperfusion injury. Traditional Chinese herbal medicines (TCHMs) boasts a rich historical background, notable efficacy, and minimal adverse effects. It exerts its effects by modulating microglia activation and polarization, suppressing inflammatory responses, and ameliorating nerve injury through the mediation of microglia and various associated pathways (such as NF-κB signaling pathway, Toll-like signaling pathway, Notch signaling pathway, AMPK signaling pathway, MAPK signaling pathway, among others). Consequently, this article focuses on microglia as a therapeutic target, reviewing relevant pathway of literature on TCHMs to mitigate neuroinflammation and mediate IS injury, while also exploring research on drug delivery of TCHMs. The ultimate goal is to provide new insights that can contribute to the clinical management of IS using TCHMs.

Biomembrane-Derived Nanoparticles in Alzheimer's Disease Therapy: A Comprehensive Review of Synthetic Lipid Nanoparticles and Natural Cell-Derived Vesicles

Current therapies for Alzheimer's disease used in the clinic predominantly focus on reducing symptoms with limited capability to control disease progression; thus, novel drugs are urgently needed. While nanoparticles (liposomes, high-density lipoprotein-based nanoparticles) constructed with synthetic biomembranes have shown great potential in AD therapy due to their excellent biocompatibility, multifunctionality and ability to penetrate the BBB, nanoparticles derived from natural biomembranes (extracellular vesicles, cell membrane-based nanoparticles) display inherent biocompatibility, stability, homing ability and ability to penetrate the BBB, which may present a safer and more effective treatment for AD. In this paper, we reviewed the synthetic and natural biomembrane-derived nanoparticles that are used in AD therapy. The challenges associated with the clinical translation of biomembrane-derived nanoparticles and future perspectives are also discussed.

Recent progress in nanotechnology-based drug carriers for resveratrol delivery

Resveratrol is a polyphenol with diverse pharmacological activities, but its clinical efficacy is limited due to low solubility/permeability, light-induced isomerization, auto-oxidation, and rapid metabolism. Nanodelivery systems, such as liposomes, polymeric nanoparticles, lipid nanocarriers, micelles, nanocrystals, inorganic nanoparticles, nanoemulsions, protein-based nanoparticles, exosomes, macrophages, and red blood cells (RBCs) have shown great potential for improving the solubility, biocompatibility, and therapeutic efficacy of resveratrol. This review comprehensively summarizes the recent advances in resveratrol nanoencapsulation and describes potential strategies to improve the pharmacokinetics of existing nanoformulations, enhance targeting, reduce toxicity, and increase drug release and encapsulation efficiency. The article also suggests that in order to avoid potential safety issues, resveratrol nanoformulations must be tested in vivo in a wide range of diseases.

The rod synapse in aging wildtype and Dscaml1 mutant mice

The retina is an intricately organized neural tissue built on cone and rod pathways for color and night vision. Genetic mutations that disrupt the proper function of the rod circuit contribute to blinding diseases including retinitis pigmentosa and congenital stationary night blindness (CSNB). Down Syndrome cell adhesion molecule like 1 (Dscaml1) is expressed by rods, rod bipolar cells (RBCs), and sub-populations of amacrine cells, and has been linked to a middle age onset of CSNB in humans. However, how Dscaml1 contributes to this visual deficit remains unexplored. Here, we probed Dscaml1's role in the maintenance of the rod-to-RBC synapse using a loss of function mouse model. We used immunohistochemistry to investigate the anatomical formation and maintenance of the rod-to-RBC synapse in the young, adult, and aging retina. We generated 3D reconstructions, using serial electron micrographs, of rod spherules and RBCs to measure the number of invaginating neurites, RBC dendritic tip number, and RBC mitochondrial morphology. We find that while rod-to-RBC synapses form and are maintained, similar to wildtype, that there is an increase in the number of invaginating neurites in rod spherules, a reduction in RBC dendritic tips, and reduced mitochondrial volume and complexity in the Dscaml1 mutant retina compared to controls. We also observed precocious sprouting of RBC dendrites into the outer nuclear layer (ONL) of the Dscaml1 mutant retina compared to controls. These results contribute to our knowledge of Dscaml1's role in rod circuit development and maintenance and give additional insight into possible genetic therapy targets for blinding diseases and disorders like CSNB.

Cell membrane-based nanomaterials for therapeutics of neurodegenerative diseases

Central nervous system (CNS) diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), glioblastoma (GBM), and peripheral nerve injury have been documented as incurable diseases, which lead to serious impacts on human health especially prevalent in the aging population worldwide. Most of the treatment strategies fail due to low efficacy, toxicity, and poor brain penetration. Recently, advancements in nanotechnology have helped alleviate the challenges associated with the application of cell membrane-based nanomaterials against CNS diseases. In the following review, the existing types of cell membrane-based nanomaterials systems which have improved therapeutic efficacy for CNS diseases would be described. A summary of recent progress in the incorporation of nanomaterials in cell membrane-based production, separation, and analysis will be provided. Addition to, challenges relate to large-scale manufacturing of cell membrane-based nanomaterials and future clinical trial of such platforms will be discussed.

Advancements in the Application of Nanomedicine in Alzheimer's Disease: A Therapeutic Perspective

Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects most people worldwide. AD is a complex central nervous system disorder. Several drugs have been designed to cure AD, but with low success rates. Because the blood-brain and blood-cerebrospinal fluid barriers are two barriers that protect the central nervous system, their presence has severely restricted the efficacy of many treatments that have been studied for AD diagnosis and/or therapy. The use of nanoparticles for the diagnosis and treatment of AD is the focus of an established and rapidly developing field of nanomedicine. Recent developments in nanomedicine have made it possible to effectively transport drugs to the brain. However, numerous obstacles remain to the successful use of nanomedicines in clinical settings for AD treatment. Furthermore, given the rapid advancement in nanomedicine therapeutics, better outcomes for patients with AD can be anticipated. This article provides an overview of recent developments in nanomedicine using different types of nanoparticles for the management and treatment of AD.

Current Advances in Mitochondrial Targeted Interventions in Alzheimer's Disease

Alzheimer's disease is the most prevalent neurodegenerative disorder and affects the lives not only of those who are diagnosed but also of their caregivers. Despite the enormous social, economic and political burden, AD remains a disease without an effective treatment and with several failed attempts to modify the disease course. The fact that AD clinical diagnosis is most often performed at a stage at which the underlying pathological events are in an advanced and conceivably irremediable state strongly hampers treatment attempts. This raises the awareness of the need to identify and characterize the early brain changes in AD, in order to identify possible novel therapeutic targets to circumvent AD's cascade of events. One of the most auspicious targets is mitochondria, powerful organelles found in nearly all cells of the body. A vast body of literature has shown that mitochondria from AD patients and model organisms of the disease differ from their non-AD counterparts. In view of this evidence, preserving and/or restoring mitochondria's health and function can represent the primary means to achieve advances to tackle AD. In this review, we will briefly assess and summarize the previous and latest evidence of mitochondria dysfunction in AD. A particular focus will be given to the recent updates and advances in the strategy options aimed to target faulty mitochondria in AD.

Cell membrane-based nanomaterials for theranostics of central nervous system diseases

Central nervous system (CNS) diseases have been widely acknowledged as one of the major healthy concerns globally, which lead to serious impacts on human health. There will be about 135 million CNS diseases cases worldwide by mid-century, and CNS diseases will become the second leading cause of death after the cardiovascular disease by 2040. Most CNS diseases lack of effective diagnostic and therapeutic strategies with one of the reasons that the biological barrier extremely hampers the delivery of theranostic agents. In recent years, nanotechnology-based drug delivery is a quite promising way for CNS diseases due to excellent properties. Among them, cell membrane-based nanomaterials with natural bio-surface, high biocompatibility and biosafety, are of great significance in both the diagnosis and treatment of different CNS diseases. In this review, the state of art of the fabrication of cell membranes-based nanomaterials is introduced. The characteristics of different CNS diseases, and the application of cell membranes-based nanomaterials in the theranostics are summarized. In addition, the future prospects and limitations of cell membrane nanotechnology are anticipated. Through summarizing the state of art of the fabrication, giving examples of CNS diseases, and highlighting the applications in theranostics, the current review provides designing methods and ideas for subsequent cell membrane nanomaterials.

An Overview of Nanostructured Lipid Carriers and its Application in Drug Delivery through Different Routes

Nanostructured Lipid Carriers (NLC) are nano-sized colloidal drug delivery system that contains a lipid mixture consisting of both solid and liquid lipids in their core. This Lipid-Based Nanosystem is introduced as a biocompatible, non-toxic, and safe nano-drug delivery system as compared to polymeric or metallic nanoparticles. Due to its safety, stability, and high drug loading capacity compared to other lipid-based nanocarriers, NLC gained the attention of researchers to formulate safe and effective drug carriers. The ability to increase drug solubility and permeability while encapsulating the drug in a lipidic shell makes them an ideal carrier for drug delivery through difficult-to-achieve routes. Surface modification of NLC and the use of various additives result in drug targeting and increased residence time. With such qualities, NLCs can be used to treat a variety of diseases such as cancer, infections, neurodegenerative diseases, hypertension, diabetes, and pain management. This review focuses on the recent developments being made to deliver the drugs and genes through different routes via these nanocarriers. Here, we also discuss about historical background, structure, types of NLC and commonly employed techniques for manufacturing lipid-based nanocarriers.

Biomimetic Gold Nanorods Modified with Erythrocyte Membranes for Imaging-Guided Photothermal/Gene Synergistic Therapy

Pancreatic cancer (PC) is one of the most malignant cancers that develops rapidly and carries a poor prognosis. Synergistic cancer therapy strategy could enhance the clinical efficacy compared to either treatment alone. In this study, gold nanorods (AuNRs) were used as siRNA delivery vehicles to interfere with the oncogenes of KRAS. In addition, AuNRs were one of anisotropic nanomaterials that can absorb near-infrared (NIR) laser and achieve rapid photothermal therapy for malignant cancer cells. Modification of the erythrocyte membrane and antibody Plectin-1 occurred on the surface of the AuNRs, making them a promising target nanocarrier for enhancing antitumor effects. As a result, biomimetic nanoprobes presented advantages in biocompatibility, targeting capability, and drug-loading efficiency. Moreover, excellent antitumor effects have been achieved by synergistic photothermal/gene treatment. Therefore, our study would provide a general strategy to construct a multifunctional biomimetic theranostic multifunctional nanoplatform for preclinical studies of PC.

Extracellular Vesicles Derived From Neural Stem Cells, Astrocytes, and Microglia as Therapeutics for Easing TBI-Induced Brain Dysfunction

Extracellular vesicles (EVs) derived from neural stem cells (NSC-EVs), astrocytes (ADEVs), and microglia (MDEVs) have neuroregenerative properties. This review discusses the therapeutic efficacy of NSC-EVs, ADEVs, and MDEVs in traumatic brain injury (TBI) models. The translational value and future directions for such EV therapy are also deliberated. Studies have demonstrated that NSC-EV or ADEV therapy can mediate neuroprotective effects and improve motor and cognitive function after TBI. Furthermore, NSC-EVs or ADEVs generated after priming parental cells with growth factors or brain-injury extracts can mediate improved therapeutic benefits. However, the therapeutic effects of naïve MDEVs are yet to be tested rigorously in TBI models. Studies using activated MDEVs have reported both adverse and beneficial effects. NSC-EV, ADEV, or MDEV therapy for TBI is not ready for clinical translation. Rigorous testing of their efficacy for preventing chronic neuroinflammatory cascades and enduring motor and cognitive impairments after treatment in the acute phase of TBI, an exhaustive evaluation of their miRNA or protein cargo, and the effects of delayed EV administration post-TBI for reversing chronic neuroinflammation and enduring brain impairments, are needed. Moreover, the most beneficial route of administration for targeting EVs into different neural cells in the brain after TBI and the efficacy of well-characterized EVs from NSCs, astrocytes, or microglia derived from human pluripotent stem cells need to be evaluated. EV isolation methods for generating clinical-grade EVs must also be developed. Overall, NSC-EVs and ADEVs promise to mitigate TBI-induced brain dysfunction, but additional preclinical studies are needed before their clinical translation.

Nano-Brake Halts Mitochondrial Dysfunction Cascade to Alleviate Neuropathology and Rescue Alzheimer's Cognitive Deficits

Mitochondrial dysfunction has been recognized as the key pathogenesis of most neurodegenerative diseases including Alzheimer's disease (AD). The dysregulation of mitochondrial calcium ion (Ca²⁺ ) homeostasis and the mitochondrial permeability transition pore (mPTP), is a critical upstream signaling pathway that contributes to the mitochondrial dysfunction cascade in AD pathogenesis. Herein, a "two-hit braking" therapeutic strategy to synergistically halt mitochondrial Ca²⁺ overload and mPTP opening to put the mitochondrial dysfunction cascade on a brake is proposed. To achieve this goal, magnesium ion (Mg²⁺ ), a natural Ca²⁺ antagonist, and siRNA to the central mPTP regulator cyclophilin D (CypD), are co-encapsulated into the designed nano-brake; A matrix metalloproteinase 9 (MMP9) activatable cell-penetrating peptide (MAP) is anchored on the surface of nano-brake to overcome the blood-brain barrier (BBB) and realize targeted delivery to the mitochondrial dysfunction cells of the brain. Nano-brake treatment efficiently halts the mitochondrial dysfunction cascade in the cerebrovascular endothelial cells, neurons, and microglia and powerfully alleviates AD neuropathology and rescues cognitive deficits. These findings collectively demonstrate the potential of advanced design of nanotherapeutics to halt the key upstream signaling pathways of mitochondrial dysfunction to provide a powerful strategy for AD modifying therapy.

Nanoparticles loaded with pharmacologically active plant-derived natural products: Biomedical applications and toxicity

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.

Parenteral Lipid-Based Nanoparticles for CNS Disorders: Integrating Various Facets of Preclinical Evaluation towards More Effective Clinical Translation

Contemporary trends in combinatorial chemistry and the design of pharmaceuticals targeting brain disorders have favored the development of drug candidates with increased lipophilicity and poorer water solubility, with the expected improvement in delivery across the blood-brain barrier (BBB). The growing availability of innovative excipients/ligands allowing improved brain targeting and controlled drug release makes the lipid nanocarriers a reasonable choice to overcome the factors impeding drug delivery through the BBB. However, a wide variety of methods, study designs and experimental conditions utilized in the literature hinder their systematic comparison, and thus slows the advances in brain-targeting by lipid-based nanoparticles. This review provides an overview of the methods most commonly utilized during the preclinical testing of liposomes, nanoemulsions, solid lipid nanoparticles and nanostructured lipid carriers intended for the treatment of various CNS disorders via the parenteral route. In order to fully elucidate the structure, stability, safety profiles, biodistribution, metabolism, pharmacokinetics and immunological effects of such lipid-based nanoparticles, a transdisciplinary approach to preclinical characterization is mandatory, covering a comprehensive set of physical, chemical, in vitro and in vivo biological testing.

Drug Discovery and Development Targeting Dementia

Dementia, most often associated with neurodegenerative diseases, affects millions of people worldwide, predominantly the elderly. Unfortunately, no treatment is still available. Therefore, there is an urgent need to address this situation. This review presents the state of the art of drug discovery and developments in targeting dementia. Several approaches are discussed, such as drug repurposing, the use of small molecules, and phosphodiesterase inhibitors. Furthermore, the review also provides insights into clinical trials of these molecules. Emphasis has been placed on small molecules and multi-target-directed ligands, as well as disease-modifying therapies. Finally, attention is drawn to the possibilities of applications of nanotechnology in managing dementia.

Role of traditional Chinese medicine in ameliorating mitochondrial dysfunction via non-coding RNA signaling: Implication in the treatment of neurodegenerative diseases

Neurodegenerative diseases (NDs) are common chronic disorders associated with progressive nervous system damage, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, among others. Mitochondria are abundant in various nervous system cells and provide a bulk supply of the adenosine triphosphate necessary for brain function, considered the center of the free-radical theory of aging. One common feature of NDs is mitochondrial dysfunction, which is involved in many physiopathological processes, including apoptosis, inflammation, oxidative stress, and calcium homeostasis. Recently, genetic studies revealed extensive links between mitochondrion impairment and dysregulation of non-coding RNAs (ncRNAs) in the pathology of NDs. Traditional Chinese medicines (TCMs) have been used for thousands of years in treating NDs. Numerous modern pharmacological studies have demonstrated the therapeutic effects of prescription, herbal medicine, bioactive ingredients, and monomer compounds of TCMs, which are important for managing the symptoms of NDs. Some highly effective TCMs exert protective effects on various key pathological features regulated by mitochondria and play a pivotal role in recovering disrupted signaling pathways. These disrupted signaling pathways are induced by abnormally-expressed ncRNAs associated with mitochondrial dysfunction, including microRNAs, long ncRNAs, and circular RNAs. In this review, we first explored the underlying ncRNA mechanisms linking mitochondrial dysfunction and neurodegeneration, demonstrating the implication of ncRNA-induced mitochondrial dysfunction in the pathogenesis of NDs. The ncRNA-induced mitochondrial dysfunctions affect mitochondrial biogenesis, dynamics, autophagy, Ca²⁺ homeostasis, oxidative stress, and downstream apoptosis. The review also discussed the targeting of the disease-related mitochondrial proteins in NDs and the protective effects of TCM formulas with definite composition, standardized extracts from individual TCMs, and monomeric compounds isolated from TCM. Additionally, we explored the ncRNA regulation of mitochondrial dysfunction in NDs and the effects and potential mechanisms of representative TCMs in alleviating mitochondrial pathogenesis and conferring anti-inflammatory, antioxidant, and anti-apoptotic pathways against NDs. Therefore, this review presents an overview of the role of mitochondrion-related ncRNAs and the target genes for TCM-based therapeutic interventions in NDs, providing insight into understanding the "multi-level compound-target-pathway regulatory" treatment mechanism of TCMs.

Identification of Copper Metabolism Related Biomarkers, Polygenic Prediction Model, and Potential Therapeutic Agents in Alzheimer's Disease

BACKGROUND

The underlying pathogenic genes and effective therapeutic agents of Alzheimer's disease (AD) are still elusive. Meanwhile, abnormal copper metabolism is observed in AD brains of both human and mouse models.

OBJECTIVE

To investigate copper metabolism-related gene biomarkers for AD diagnosis and therapy.

METHODS

The AD datasets and copper metabolism-related genes (CMGs) were downloaded from GEO and GeneCards database, respectively. Differentially expressed CMGs (DE-CMGs) performed through Limma, functional enrichment analysis and the protein-protein interaction were used to identify candidate key genes by using CytoHubba. And these candidate key genes were utilized to construct a prediction model by logistic regression analysis for AD early diagnosis. Furthermore, ROC analysis was conducted to identify a single gene with AUC values greater than 0.7 by GSE5281. Finally, the single gene biomarker was validated by quantitative real-time polymerase chain reaction (qRT-PCR) in AD clinical samples. Additionally, immune cell infiltration in AD samples and potential therapeutic drugs targeting the identified biomarkers were further explored.

RESULTS

A polygenic prediction model for AD based on copper metabolism was established by the top 10 genes, which demonstrated good diagnostic performance (AUC values). COX11, LDHA, ATOX1, SCO1, and SOD1 were identified as blood biomarkers for AD early diagnosis. 20 agents targeting biomarkers were retrieved from DrugBank database, some of which have been proven effective for the treatment of AD.

CONCLUSIONS

The five blood biomarkers and copper metabolism-associated model can differentiate AD patients from non-demented individuals and aid in the development of new therapeutic strategies.

Cognition Enhancing Potential of Aqueous Leaf Extract of Amaranthus dubius in Mice

Amaranthus dubius is a vegetable consumed for its nutritional content in Kenya. In herbal medicine, A. dubius is utilized to relief fever, anemia and hemorrhage. Additionally, it is utilized to manage cognitive dysfunction and is considered to augment brain function, but there is no empirical evidence to support this claim. The contemporary study investigated cognitive enhancing potential of A. dubius in mice model of Alzheimer's disease (AD)-like dementia induced with ketamine. Cognitively damaged mice were treated with aqueous extract of A. dubius leaf upon which passive avoidance task (PAT) was used to assess the cognitive performance. At the end of passive avoidance test, brains of the mice were dissected to evaluate the possibility of the extract to inhibit hallmarks that propagate AD namely oxidative stress and acetylcholinesterase activity. Additionally, characterization of secondary metabolites was done using liquid chromatograph- mass spectrometry analysis. During PAT test, extract-treated mice showed significantly increased step-through latencies than AD mice, depicting ability of A. dubius to reverse ketamine-induced cognitive decline. Further, the extract remarkably lowered malondialdehyde levels to normal levels and effectively inhibited acetylcholinesterase enzyme. The study showed that A. dubius extract is endowed with phytoconstituents that possess anti-oxidant and anticholinesterase activities. Thus, this study confirmed promising therapeutic effects of 200, 300 and 400 mg/kg bw of A. dubius extract with potential to alleviate cognitive disarray observed in AD.

Mitochondrial dysfunctions, oxidative stress and neuroinflammation as therapeutic targets for neurodegenerative diseases: An update on current advances and impediments

Neurodegenerative diseases (NDs) such as Alzheimer disease (AD), Parkinson disease (PD), and Huntington disease (HD) represent a major socio-economic challenge in view of their high prevalence yet poor treatment outcomes affecting quality of life. The major challenge in drug development for these NDs is insufficient clarity about the mechanisms involved in pathogenesis and pathophysiology. Mitochondrial dysfunction, oxidative stress and inflammation are common pathways that are linked to neuronal abnormalities and initiation of these diseases. Thus, elucidating the shared initial molecular and cellular mechanisms is crucial for recognizing novel remedial targets, and developing therapeutics to impede or stop disease progression. In this context, use of multifunctional compounds at early stages of disease development unclogs new avenues as it acts on act on multiple targets in comparison to single target concept. In this review, we summarize overview of the major findings and advancements in recent years focusing on shared mechanisms for better understanding might become beneficial in searching more potent pharmacological interventions thereby reducing the onset or severity of various NDs.

Nanoparticles-based delivery system and its potentials in treating central nervous system disorders

Central nervous system (CNS) disorders, such as Alzheimer's disease (AD) and Parkinson's disease (PD), have become severe health concern worldwide. The treatment of the CNS diseases is of great challenges due largely to the presence of the blood-brain barrier (BBB). On the one hand, BBB protects brain from the harmful exogenous molecules via inhibiting their entry into the brain. On the other hand, it also hampers the transport of therapeutic drugs into the brain, resulting in the difficulties in treating the CNS diseases. In the past decades, nanoparticles-based drug delivery systems have shown great potentials in overcoming the BBB owing to their unique physicochemical properties, such as small size and specific morphology. In addition, functionalization of nanomaterials confers these nanocarriers controlled drug release features and targeting capacities. These properties make nanocarriers the potent delivery systems for treating the CNS disorders. Herein, we summarize the recent progress in nanoparticles-based systems for the CNS delivery, including the conventional and innovative systems. The prerequisites, drawbacks and challenges of nanocarriers (such as protein corona formation) in the CNS delivery are also discussed.

New Mechanisms and Targets of Subarachnoid Hemorrhage: A Focus on Mitochondria

Spontaneous subarachnoid hemorrhage (SAH) accounts for 5-10% of all strokes and is a subtype of hemorrhagic stroke that places a heavy burden on health care. Despite great progress in surgical clipping and endovascular treatment for ruptured aneurysms, cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) threaten the long-term outcomes of patients with SAH. Moreover, there are limited drugs available to reduce the risk of DCI and adverse outcomes in SAH patients. New insight suggests that early brain injury (EBI), which occurs within 72 h after the onset of SAH, may lay the foundation for further DCI development and poor outcomes. The mechanisms of EBI mainly include excitotoxicity, oxidative stress, neuroinflammation, blood-brain barrier (BBB) destruction, and cellular death. Mitochondria are a double-membrane organelle, and they play an important role in energy production, cell growth, differentiation, apoptosis, and survival. Mitochondrial dysfunction, which can lead to mitochondrial membrane potential (Δψm) collapse, overproduction of reactive oxygen species (ROS), release of apoptogenic proteins, disorders of mitochondrial dynamics, and activation of mitochondria-related inflammation, is considered a novel mechanism of EBI related to DCI as well as post-SAH outcomes. In addition, mitophagy is activated after SAH. In this review, we discuss the latest perspectives on the role of mitochondria in EBI and DCI after SAH. We emphasize the potential of mitochondria as therapeutic targets and summarize the promising therapeutic strategies targeting mitochondria for SAH.

Extrahepatic targeting of lipid nanoparticles in vivo with intracellular targeting for future nanomedicines

A new era of nanomedicines that involve nucleic acids/gene therapy has been opened after two decades in 21^st century and new types of more efficient drug delivery systems (DDS) are highly expected and will include extrahepatic delivery. In this review, we summarize the possibility and expectations for the extrahepatic delivery of small interfering RNA/messenger RNA/plasmid DNA/genome editing to the spleen, lung, tumor, lymph nodes as well as the liver based on our studies as well as reported information. Passive targeting and active targeting are discussed in in vivo delivery and the importance of controlled intracellular trafficking for successful therapeutic results are also discussed. In addition, mitochondrial delivery as a novel strategy for nucleic acids/gene therapy is introduced to expand the therapeutic dimension of nucleic acids/gene therapy in the liver as well as the heart, kidney and brain.

Natural Product-based Nanomedicine: Recent Advances and Issues for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) affects the elderly and is characterized by progressive neurodegeneration caused by different pathologies. The most significant challenges in treating AD include the inability of medications to reach the brain because of its poor solubility, low bioavailability, and the presence of the blood-brain barrier (BBB). Additionally, current evidence suggests the disruption of BBB plays an important role in the pathogenesis of AD. One of the critical challenges in treating AD is the ineffective treatments and their severe adverse effects. Nanotechnology offers an alternative approach to facilitate the treatment of AD by overcoming the challenges in drug transport across the BBB. Various nanoparticles (NP) loaded with natural products were reported to aid in drug delivery for the treatment of AD. The nano-sized entities of NP are great platforms for incorporating active materials from natural products into formulations that can be delivered effectively to the intended action site without compromising the material's bioactivity. The review highlights the applications of medicinal plants, their derived components, and various nanomedicinebased approaches for the treatment of AD. The combination of medicinal plants and nanotechnology may lead to new theragnostic solutions for the treatment of AD in the future.

Benefits and limitations of nanomedicine treatment of brain cancers and age-dependent neurodegenerative disorders

The treatment of central nervous system (CNS) malignancies, including brain cancers, is limited by a number of obstructions, including the blood-brain barrier (BBB), the heterogeneity and high invasiveness of tumors, the inaccessibility of tissues for early diagnosis and effective surgery, and anti-cancer drug resistance. Therapies employing nanomedicine have been shown to facilitate drug penetration across the BBB and maintain biodistribution and accumulation of therapeutic agents at the desired target site. The application of lipid-, polymer-, or metal-based nanocarriers represents an advanced drug delivery system for a growing group of anti-cancer chemicals. The nanocarrier surface is designed to contain an active ligand (cancer cell marker or antibody)-binding structure which can be modified to target specific cancer cells. Glioblastoma, ependymoma, neuroblastoma, medulloblastoma, and primary CNS lymphomas were recently targeted by easily absorbed nanocarriers. The metal- (such as transferrin drug-loaded systems), polymer- (nanocapsules and nanospheres), or lipid- (such as sulfatide-containing nanoliposomes)-based nano-vehicles were loaded with apoptosis- and/or ferroptosis-stimulating agents and demonstrated promising anti-cancer effects. This review aims to discuss effective nanomedicine approaches designed to overcome the current limitations in the therapy of brain cancers and age-dependent neurodegenerative disorders. To accent current obstacles for successful CNS-based cancer therapy, we discuss nanomedicine perspectives and limitations of nanodrug use associated with the specificity of nervous tissue characteristics and the effects nanocarriers have on cognition.

Therapeutic nanotechnologies for Alzheimer's disease: a critical analysis of recent trends and findings

Alzheimer's Disease (AD) is an irreversible neurodegenerative disease for which no disease modifying therapies are presently available. Besides the identification of pathological targets, AD presents numerous clinical and pharmacological challenges such as efficient active delivery to the central nervous system, cell targeting, and long-term dosing. Nanoparticles have been explored to overcome some of these challenges as drug delivery vehicles or drugs themselves. However, early promises have failed to materialize as no nanotechnology-based product has been able to reach the market and very few have moved past preclinical stages. In this review, we perform a critical analysis of the past decade's research on nanomedicine-based therapies for AD at the preclinical and clinical stages. The main obstacles to nanotechnology products and the most promising approaches were also identified, including renewed promise with gene editing, gene modulation, and vaccines.

Preparation of baicalin-loaded ligand-modified nanoparticles for nose-to-brain delivery for neuroprotection in cerebral ischemia

Neuroprotection in cerebral ischemia (CI) has received increasing attention. However, efficient delivery of therapeutic agents to the brain remains a major challenge due to the complex environment of the brain. Nose-to-brain-based delivery is a promising approach. Here, we optimized a nanocarrier formulation of neuroprotective agents that can be used for nose-to-brain delivery by obtaining RVG29 peptide-modified polyethylene glycol–polylactic acid-co-glycolic acid nanoparticles (PEG–PLGA RNPs) that have physicochemical properties that lead to stable and sustained drug release and thereby improve the bioavailability of neuroprotective agents. The brain-targeting ability of PEG–PLGA RNPs administered through nasal inhalation was verified in a rat model of CI. It was found that delivery to the whole brain can be achieved with little delivery to the peripheral circulation. Baicalin (BA) was selected as the neuroprotective agent for delivery. After intranasal administration of BA–PEG–PLGA RNPs, the neurological dysfunction of rats with ischemic brain injury was significantly alleviated, the cerebral infarction area was reduced, and nerve trauma and swelling were relieved. Furthermore, it was demonstrated that the neuroprotective effects of BA in a rat model of CI may be mediated by inhibition of inflammation and alleviation of oxidative stress. The immunohistochemical results obtained after treatment with nanoparticles loaded with BA showed that Nrf2/HO-1 was activated in the area in which ischemic brain damage had occurred and that its expression was significantly higher in the group treated with BA–PEG–PLGA RNPs than in the other groups. The ELISA results showed that the levels of IL-1β, IL-6, and TNF-α were abnormally increased in the serum of rats with cerebral ischemia. After treatment with BA-loaded nanoparticles, IL-1β, IL-6, and TNF-α levels decreased significantly. Oxidative stress was alleviated; the levels of glutathione and superoxide dismutase increased; and the levels of reactive oxygen species and malondialdehyde decreased, in animals to which BA–PEG–PLGA RNPs were delivered by intranasal inhalation. In conclusion, BA–PEG–PLGA RNPs can effectively deliver BA to rats and thereby exert neuroprotective effects against CI.

Mitochondria targeting drugs for neurodegenerative diseases—design, mechanism and application

Neurodegenerative diseases (NDDs) such as Alzheimer's disease (AD) and Parkinson's disease (PD) are a heterogeneous group of disorders characterized by progressive degeneration of neurons. NDDs threaten the lives of millions of people worldwide and regretfully remain incurable. It is well accepted that dysfunction of mitochondria underlies the pathogenesis of NDDs. Dysfunction of mitochondria results in energy depletion, oxidative stress, calcium overloading, caspases activation, which dominates the neuronal death of NDDs. Therefore, mitochondria are the preferred target for intervention of NDDs. So far various mitochondria-targeting drugs have been developed and delightfully some of them demonstrate promising outcome, though there are still some obstacles such as targeting specificity, delivery capacity hindering the drugs development. In present review, we will elaborately address 1) the strategy to design mitochondria targeting drugs, 2) the rescue mechanism of respective mitochondria targeting drugs, 3) how to evaluate the therapeutic effect. Hopefully this review will provide comprehensive knowledge for understanding how to develop more effective drugs for the treatment of NDDs.

A smart cauliflower-like carrier for astaxanthin delivery to relieve colon inflammation

As a fat-soluble carotenoid, astaxanthin has excellent antioxidant and anti-inflammation biological activities, but its poor biocompatibility and low stability limit application of astaxanthin in the food industry. In this study, cauliflower-like carriers (CCs) were constructed based on caseinate, chitosan-triphenylphosphonium (TPP) and sodium alginate through an electrostatic self-assembly method to improve the biocompatibility, stability and targeting transport properties of astaxanthin. The smart CCs showed pH-response release and mitochondrial targeted characteristics. In vitro studies demonstrated that the CCs could improve the internalization of astaxanthin, and significantly inhibited the excessive production of reactive oxygen species and the depolarization of mitochondrial membrane potential caused by oxidative stress. In vivo studies revealed that the astaxanthin-loaded CCs could effectively relieve the colitis induced by dextran sodium sulfate and protect the integrity of the colon tissue structure. The astaxanthin-loaded CCs could significantly inhibit the expression of inflammation factors such as interleukin-1β, interleukin-6, tumor necrosis factor alpha, cyclooxygenase-2, myeloperoxidase, inducible nitric oxide synthase, and nitric oxide. Moreover, the astaxanthin-loaded CCs could maintain the expression of zonula occludens-1, increase the abundance of Firmicutes and Lactobacillaceae in the intestine. In a word, the constructed astaxanthin delivery system provided a potential application for the oral uptake hydrophobic bio-activator in intervention of ulcerative colitis.

Discerning the Role of Blood Brain Barrier Dysfunction in Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common form of neurodegenerative disease. The predominant characteristics of AD are the accumulation of amyloid-β (Aβ) and hyperphosphorylated tau in the brain. Blood brain barrier (BBB) dysfunction as one of the causative factors of cognitive impairment is increasingly recognized in the last decades. However, the role of BBB dysfunction in AD pathogenesis is still not fully understood. It remains elusive whether BBB dysfunction is a consequence or causative fact of Aβ pathology, tau pathology, neuroinflammation, or other conditions. In this review, we summarized the major findings of BBB dysfunction in AD and the reciprocal relationships between BBB dysfunction, Aβ pathology, tau pathology, and neuroinflammation. In addition, the implications of BBB dysfunction in AD for delivering therapeutic drugs were presented. Finally, we discussed how to better determine the underlying mechanisms between BBB dysfunction and AD, as well as how to explore new therapies for BBB regulation to treat AD in the future.

Nano-Traditional Chinese Medicine: a promising strategy and its recent advances

Traditional Chinese medicine(TCM) has been applied to the prevention and treatment of numerous diseases and has an irreplaceable role of rehabilitation and health care. However, the application of TCM is...

Research Progress on Cell Membrane-Coated Biomimetic Delivery Systems

Cell membrane-coated biomimetic nanoplatforms have many inherent properties, such as bio-interfacing abilities, self-identification, and signal transduction, which enable the biomimetic delivery system to escape immune clearance and opsonization. This can also maximize the drug delivery efficiency of synthetic nanoparticles (NPs) and functional cell membranes. As a new type of delivery system, cell membrane-coated biomimetic delivery systems have broadened the prospects for biomedical applications. In this review, we summarize research progress on cell membrane biomimetic technology from three aspects, including sources of membrane, modifications, and applications, then analyze their limitations and propose future research directions.

Cepharanthine loaded nanoparticles coated with macrophage membranes for lung inflammation therapy

Acute lung injury (ALI) is a disease associated with suffering and high lethality, but to date without any effective pharmacological management in the clinic. In the pathological mechanisms of ALI, a strong inflammatory response plays an important role. Herein, based on macrophage 'homing' into inflammation sites and cell membrane coating nanotechnology, we developed a biomimetic anti-inflammation nanosystem (MM-CEP/NLCs) for the treatment of ALI. MM-CEP/NLCs were made with nanostructured lipid carriers (NLCs) coated with natural macrophage membranes (MMs) to achieve effective accumulation of cepharanthine (CEP) in lung inflammation to achieve the effect of treating ALI. With the advantage of suitable physicochemical properties of NLCs and unique biological functions of the macrophage membrane, MM-CEP/NLCs were stabilized and enabled sustained drug release, providing improved biocompatibility and long-term circulation. In vivo, the macrophage membranes enabled NLCs to be targeted and accumulated in the inflammation sites. Further, MM-CEP/NLCs significantly attenuated the severity of ALI, including lung water content, histopathology, bronchioalveolar lavage cellularity, protein concentration, and inflammation cytokines. Our results provide a bionic strategy via the biological properties of macrophages, which may have greater value and application prospects in the treatment of inflammation.

Nanotechnology-Based Drug Delivery Strategies to Repair the Mitochondrial Function in Neuroinflammatory and Neurodegenerative Diseases

Mitochondria are vital organelles in eukaryotic cells that control diverse physiological processes related to energy production, calcium homeostasis, the generation of reactive oxygen species, and cell death. Several studies have demonstrated that structural and functional mitochondrial disturbances are involved in the development of different neuroinflammatory (NI) and neurodegenerative (ND) diseases (NI&NDDs) such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Remarkably, counteracting mitochondrial impairment by genetic or pharmacologic treatment ameliorates neurodegeneration and clinical disability in animal models of these diseases. Therefore, the development of nanosystems enabling the sustained and selective delivery of mitochondria-targeted drugs is a novel and effective strategy to tackle NI&NDDs. In this review, we outline the impact of mitochondrial dysfunction associated with unbalanced mitochondrial dynamics, altered mitophagy, oxidative stress, energy deficit, and proteinopathies in NI&NDDs. In addition, we review different strategies for selective mitochondria-specific ligand targeting and discuss novel nanomaterials, nanozymes, and drug-loaded nanosystems developed to repair mitochondrial function and their therapeutic benefits protecting against oxidative stress, restoring cell energy production, preventing cell death, inhibiting protein aggregates, and improving motor and cognitive disability in cellular and animal models of different NI&NDDs.

Mitochondria-targeted nanoparticles in treatment of neurodegenerative diseases

Neurodegenerative diseases (NDs) are a class of heterogeneous diseases that includes Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Mitochondria play an important role in oxidative balance and metabolic activity of neurons; therefore, mitochondrial dysfunction is associated with NDs and mitochondria are considered a potential treatment target for NDs. Several obstacles, including the blood-brain barrier (BBB) and cell/mitochondrial membranes, reduce the efficiency of drug entry into the target lesions. Therefore, a variety of neuron mitochondrial targeting strategies has been developed. Among them, nanotechnology-based treatments show especially promising results. Owing to their adjustable size, appropriate charge, and lipophilic surface, nanoparticles (NPs) are the ideal theranostic system for crossing the BBB and targeting the neuronal mitochondria. In this review, we discussed the role of dysfunctional mitochondria in ND pathogenesis as well as the physiological barriers to various treatment strategies. We also reviewed the use and advantages of various NPs (including organic, inorganic, and biological membrane-coated NPs) for the treatment and diagnosis of NDs. Finally, we summarized the evidence and possible use for the promising role of NP-based theranostic systems in the treatment of mitochondrial dysfunction-related NDs.

Dimethyl Fumarate is a Potential Therapeutic Option for Alzheimer's Disease

BACKGROUND

Dimethyl fumarate (DMF) has been approved for clinical treatment of multiple sclerosis based on its antioxidant and anti-inflammatory effects by activating the Nrf2 pathway. Since both oxidative stress and inflammation are involved in Alzheimer's disease (AD), DMF is a potential therapeutic option for AD.

OBJECTIVE

This study aims to test the therapeutic effects of DMF on AD model mice and to reveal its underlying molecular mechanisms.

METHODS

Cell viability assay and in vitro immunofluorescence imaging were used to evaluate the antioxidant effect of DMF on embryonic mouse hippocampal neurons. Behavioral test and brain magnetic resonance imaging were used to assess the therapeutic effects of DMF on spatial learning and memory as well as hippocampal volume in AD model mice with and without Nrf2 knockdown. Western blotting was used to analyze the expression of antioxidant enzymes and molecules associated with AD-related pathological pathways.

RESULTS

DMF inhibits reactive oxygen species overproduction and protects neurons without Nrf2 knockdown from death. DMF reduces amyloid-β induced memory impairment and hippocampal atrophy in AD model mice rather than in Nrf2 knockdown AD mice. DMF delays the progression of AD by activating the Nrf2 pathway to enhance the expression of downstream antioxidant enzymes and inhibits lipid peroxidation, apoptosis, inflammation, mitochondrial dysfunction and amyloid-β deposition.

CONCLUSION

These results indicate that DMF is a potential therapeutic option for AD through its antioxidant, anti-inflammatory, anti-apoptotic, and other anti-AD effects by activating the Nrf2 pathway.

Cell-derived extracellular vesicles and membranes for tissue repair

Humans have a limited postinjury regenerative ability. Therefore, cell-derived biomaterials have long been utilized for tissue repair. Cells with multipotent differentiation potential, such as stem cells, have been administered to patients for the treatment of various diseases. Researchers expected that these cells would mediate tissue repair and regeneration through their multipotency. However, increasing evidence has suggested that in most stem cell therapies, the paracrine effect but not cell differentiation or regeneration is the major driving force of tissue repair. Additionally, ethical and safety problems have limited the application of stem cell therapies. Therefore, nonliving cell-derived techniques such as extracellular vesicle (EV) therapy and cell membrane-based therapy to fulfil the unmet demand for tissue repair are important. Nonliving cell-derived biomaterials are safer and more controllable, and their efficacy is easier to enhance through bioengineering approaches. Here, we described the development and evolution from cell therapy to EV therapy and cell membrane-based therapy for tissue repair. Furthermore, the latest advances in nonliving cell-derived therapies empowered by advanced engineering techniques are emphatically reviewed, and their potential and challenges in the future are discussed.

Mitochondrial defects: An emerging theranostic avenue towards Alzheimer's associated dysregulations

Mitochondria play a crucial role in expediting the energy homeostasis under varying environmental conditions. As mitochondria are controllers of both energy production and apoptotic pathways, they are also distinctively involved in controlling the neuronal cell survival and/or death. Numerous factors are responsible for mitochondria to get degraded with aging and huge functional failures in mitochondria are also found to be associated with the commencement of numerous neurodegenerative conditions, including Alzheimer's disease (AD). A large number of existing literatures promote the pivotal role of mitochondrial damage and oxidative impairment in the pathogenesis of AD. Numerous mitochondria associated processes such as mitochondrial biogenesis, fission, fusion, mitophagy, transportation and bioenergetics are crucial for proper functioning of mitochondria but are reported to be defective in AD patients. Though, the knowledge on the precise and in-depth mechanisms of these actions is still in infancy. Based upon the outcome of various significant studies, mitochondria are also being considered as therapeutic targets for AD. Here, we review the current status of mitochondrial defects in AD and also summarize the possible role of these defects in the pathogenesis of AD. The various approaches for developing the mitochondria-targeted therapies are also discussed here in detail. Consequently, it is suggested that improving mitochondrial activity via pharmacological and/or non-pharmacological interventions could postpone the onset and slow the development of AD. Further research and consequences of ongoing clinical trials should extend our understanding and help to validate conclusions regarding the causation of AD.

Toward the next-generation phyto-nanomedicines: cell-derived nanovesicles (CDNs) for natural product delivery

Phytochemicals are plant-derived bioactive compounds, which have been widely used for therapeutic purposes. Due to the poor water-solubility, low bioavailability and non-specific targeting characteristic, diverse classes of nanocarriers are utilized for encapsulation and delivery of bio-effective agents. Cell-derived nanovesicles (CDNs), known for exosomes or extracellular vesicles (EVs), are biological nanoparticles with multiple functions. Compared to the artificial counterpart, CDNs hold great potential in drug delivery given the higher stability, superior biocompatibility and the lager capability of encapsulating bioactive molecules. Here, we provide a bench-to-bedside review of CDNs-based nanoplatform, including the bio-origin, preparation, characterization and functionalization. Beyond that, the focus is laid on the therapeutic effect of CDNs-mediated drug delivery for natural products. The state-of-art development as well as some pre-clinical applications of using CDNs for disease treatment is also summarized. It is highly expected that the continuing development of CDNs-based delivery systems will further promote the clinical utilization and translation of phyto-nanomedicines.

Multifunctional Metal-Organic Framework as a Versatile Nanoplatform for Aβ Oligomer Imaging and Chemo-Photothermal Treatment in Living Cells

In view of the close association of β-amyloid oligomers (AβO) with the clinical development of Alzheimer's disease (AD) symptoms, it is urgent to design a promising sensing and therapeutic strategy that can target AβO for preventing or delaying the onset of AD. Herein, a core-shell nanocomposite CeONP-Res-PCM@ZIF-8/polydopamine (PDA) was synthesized through an in situ encapsulated strategy, in which resveratrol (Res), ceria nanoparticles (CeONPs), and PCM (tetradecanol) were embedded into the ZIF-8/PDA matrix via a water-based mild approach. Using the AβO aptamer, the ability of CeONP-Res-PCM@ZIF-8/PDA/Apt as the fluorescent sensing platform for AβO detection and intracellular imaging was demonstrated. The nanocomposite was high in Res loading (27.5%) and could be activated to release the encapsulated Res upon illumination with NIR through PCM regulation. Moreover, due to the synergetic interactions of PDA, CeONPs, and Res in one system, CeONP-Res-PCM@ZIF-8/PDA/Apt nanocomposites exhibited multifunctional effects on inhibiting Aβ aggregation, degrading Aβ fibrils, and alleviating Aβ-induced oxidative stress and neural apoptosis. These therapeutic effects could be enhanced under NIR irradiation by virtue of the excellent photothermal property of PDA. As far as we know, there is no report of using ZIF-8-based materials for simultaneous sensing and therapeutic applications. This work boosted the development of multifunctional nanoagents for biomedical research studies.

Astrocyte-derived exosomes protect hippocampal neurons after traumatic brain injury by suppressing mitochondrial oxidative stress and apoptosis

In this study, we investigated the mechanisms through which astrocyte-derived exosomes (AS-Exos) alleviate traumatic brain injury (TBI)-induced neuronal defects in TBI model rats and mice. Treatment with AS-Exos alleviated neurobehavioral deficits, cognitive impairment, and brain edema in TBI rats. AS-Exos also significantly reduced neuronal cell loss and atrophy in the TBI rats. AS-Exos significantly reduced oxidative stress and mitochondrial H₂O₂ levels by increasing the activity of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) in the hippocampal neurons of TBI rats. TUNEL-staining assays showed that AS-Exos significantly reduced TBI-induced neuronal apoptosis. Mechanistically, AS-Exos ameliorated oxidative stress by activating Nrf2/HO-1 signaling in the hippocampus of TBI rats. In addition, the neuroprotective effects of AS-Exos were abrogated in brain-specific Nrf2-knockout mice subjected to TBI. These findings demonstrate that AS-Exos protects against TBI-induced oxidative stress and neuronal apoptosis by activating Nrf2 signaling in both rat and mouse models.