Intelligently thermoresponsive flower-like hollow nano-ruthenium system for sustained release of nerve growth factor to inhibit hyperphosphorylation of tau and neuronal damage for the treatment of Alzheimer's disease

A biomimetic upconversion nanoreactors for near-infrared driven H2 release to inhibit tauopathy in Alzheimer's disease therapy

Abnormal hyperphosphorylation of tau protein is a principal pathological hallmark in the onset of neurodegenerative disorders, such as Alzheimer's disease (AD), which can be induced by an excess of reactive oxygen species (ROS). As an antioxidant, hydrogen gas (H2) has the potential to mitigate AD by scavenging highly harmful ROS such as •OH. However, conventional administration methods of H2 face significant challenges in controlling H2 release on demand and fail to achieve effective accumulation at lesion sites. Herein, we report artificial nanoreactors that mimic natural photosynthesis to realize near-infrared (NIR) light-driven photocatalytic H2 evolution in situ. The nanoreactors are constructed by biocompatible crosslinked vesicles (CVs) encapsulating ascorbic acid and two photosensitizers, chlorophyll a (Chla) and indoline dye (Ind). In addition, platinum nanoparticles (Pt NPs) serve as photocatalysts and upconversion nanoparticles (UCNP) act as light-harvesting antennas in the nanoreacting system, and both attach to the surface of CVs. Under NIR irradiation, the nanoreactors release H2 in situ to scavenge local excess ROS and attenuate tau hyperphosphorylation in the AD mice model. Such NIR-triggered nanoreactors provide a proof-of-concept design for the great potential of hydrogen therapy against AD.

Diagnosis and therapy of Alzheimer's disease: Light-driven heterogeneous redox processes

Light-driven heterogeneous processes are promising approaches for diagnosing and treating Alzheimer's disease (AD) by regulating its relevant biomolecules. The molecular understanding of the heterogeneous interface environment and its interaction with target biomolecules is important. This review critically appraises the advances in AD early diagnosis and therapy employing heterogeneous light-driven redox processes, encompassing photoelectrochemical (PEC) biosensing, photodynamic therapy, photothermal therapy, PEC therapy, and photoacoustic therapy. The design strategies for heterogeneous interfaces based on target biomolecules and applications are also compiled. Finally, the remaining challenges and future perspectives are discussed. The present review may promote the fundamental understanding of AD diagnosis and therapy and facilitate interdisciplinary studies at the junction of nanotechnology and bioscience.

Oxidative stress modulating nanomaterials and their biochemical roles in nanomedicine

Many pathological conditions are predominantly associated with oxidative stress, arising from reactive oxygen species (ROS); therefore, the modulation of redox activities has been a key strategy to restore normal tissue functions. Current approaches involve establishing a favorable cellular redox environment through the administration of therapeutic drugs and redox-active nanomaterials (RANs). In particular, RANs not only provide a stable and reliable means of therapeutic delivery but also possess the capacity to finely tune various interconnected components, including radicals, enzymes, proteins, transcription factors, and metabolites. Here, we discuss the roles that engineered RANs play in a spectrum of pathological conditions, such as cancer, neurodegenerative diseases, infections, and inflammation. We visualize the dual functions of RANs as both generator and scavenger of ROS, emphasizing their profound impact on diverse cellular functions. The focus of this review is solely on inorganic redox-active nanomaterials (inorganic RANs). Additionally, we deliberate on the challenges associated with current RANs-based approaches and propose potential research directions for their future clinical translation.

Nanomaterials that Aid in the Diagnosis and Treatment of Alzheimer's Disease, Resolving Blood-Brain Barrier Crossing Ability

As a form of dementia, Alzheimer's disease (AD) suffers from no efficacious cure, yet AD treatment is still imperative, as it ameliorates the symptoms or prevents it from deteriorating or maintains the current status to the longest extent. The human brain is the most sensitive and complex organ in the body, which is protected by the blood-brain barrier (BBB). This yet induces the difficulty in curing AD as the drugs or nanomaterials that are much inhibited from reaching the lesion site. Thus, BBB crossing capability of drug delivery system remains a significant challenge in the development of neurological therapeutics. Fortunately, nano-enabled delivery systems possess promising potential to achieve multifunctional diagnostics/therapeutics against various targets of AD owing to their intriguing advantages of nanocarriers, including easy multifunctionalization on surfaces, high surface-to-volume ratio with large payloads, and potential ability to cross the BBB, making them capable of conquering the limitations of conventional drug candidates. This review, which focuses on the BBB crossing ability of the multifunctional nanomaterials in AD diagnosis and treatment, will provide an insightful vision that is conducive to the development of AD-related nanomaterials.

Brain-Targeted Black Phosphorus-Based Nanotherapeutic Platform for Enhanced Hypericin Delivery in Depression

Depression is a significant global health concern that remains inadequately treated due to the limited effectiveness of conventional drug therapies. One potential therapeutic agent, hypericin (HYP), is identified as an effective natural antidepressant. However, its poor water solubility, low bioavailability, and limited ability to penetrate the brain parenchyma have hindered its clinical application. To address these shortcomings and enhance the therapeutic efficacy of HYP, it is loaded onto black phosphorus nanosheets (BP) modified with the neural cell-targeting peptide RVG29 to synthesize a nanoplatform named BP-RVG29@HYP (BRH). This platform served as a nanocarrier for HYP and integrated the advantages of BP with advanced delivery methods and precise targeting strategies. Under the influence of 808 nm near-infrared irradiation (NIR), BRH effectively traversed an in vitro BBB model. In vivo experiments validated these findings, demonstrating that treatment with BRH significantly alleviated depressive-like behaviors and oxidative stress in mice. Importantly, BRH exhibited an excellent safety profile, causing minimal adverse effects, which highlighted its potential as a promising therapeutic agent. In brief, this novel nanocarrier holds great promise in the development of antidepressant drugs and can create new avenues for the treatment of depression.

Aβ42 and ROS dual-targeted multifunctional nanocomposite for combination therapy of Alzheimer's disease

Amyloid-β (Aβ) readily misfolds into neurotoxic aggregates, generating high levels of reactive oxygen species (ROS), leading to progressive oxidative damage and ultimately cell death. Therefore, simultaneous inhibition of Aβ aggregation and scavenging of ROS may be a promising therapeutic strategy to alleviate Alzheimer's disease pathology. Based on the previously developed antibody 1F12 that targets all forms of Aβ42, we developed an Aβ42 and ROS dual-targeting nanocomposite using biodegradable mesoporous silica nanoparticles as carriers to load ultra-small cerium oxide nanocrystals (bMSNs@Ce-1F12). By modifying the brain-targeted rabies virus glycoprotein 29 (RVG29-bMSNs@Ce-1F12), this intelligent nanocomposite can efficiently target brain Aβ-rich regions. Combined with peripheral and central nervous system treatments, RVG29-bMSNs@Ce-1F12 can significantly alleviate AD symptoms by inhibiting Aβ42 misfolding, accelerating Aβ42 clearance, and scavenging ROS. Furthermore, this synergistic effect of ROS scavenging and Aβ clearance exhibited by this Aβ42 and ROS dual-targeted strategy also reduced the burden of hyperphosphorylated tau, alleviated glial cell activation, and ultimately improved cognitive function in APP/PS1 mice. Our findings indicate that RVG29-bMSNs@Ce-1F12 is a promising nanodrug that can facilitate multi-target treatment of AD.

Highly Bioadaptable Hybrid Conduits with Spatially Bidirectional Structure for Precision Nerve Fiber Regeneration via Gene Therapy

Peripheral nerve deficits give rise to motor and sensory impairments within the limb. The clinical restoration of extensive segmental nerve defects through autologous nerve transplantation often encounters challenges such as axonal mismatch and suboptimal functional recovery. These issues may stem from the limited regenerative capacity of proximal axons and the subsequent Wallerian degeneration of distal axons. To achieve the integration of sensory and motor functions, a spatially differential plasmid DNA (pDNA) dual-delivery nanohydrogel conduit scaffold is devised. This innovative scaffold facilitates the localized administration of the transforming growth factor β (TGF-β) gene in the proximal region to accelerate nerve regeneration, while simultaneously delivering nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) to the distal region to mitigate Wallerian degeneration. By promoting autonomous and selective alignment of nerve fiber gap sutures via structure design, the approach aims to achieve a harmonious unification of nerve regeneration, neuromotor function, and sensory recovery. It is anticipated that this groundbreaking technology will establish a robust platform for gene delivery in tissue engineering.

The Role of Reactive Oxygen Species in Alzheimer's Disease: From Mechanism to Biomaterials Therapy

Alzheimer's disease (AD) is a chronic, insidious, and progressive neurodegenerative disease that remains a clinical challenge for society. The fully approved drug lecanemab exhibits the prospect of therapy against the pathological processes, while debatable adverse events conflict with the drug concentration required for the anticipated therapeutic effects. Reactive oxygen species (ROS) are involved in the pathological progression of AD, as has been demonstrated in much research regarding oxidative stress (OS). The contradiction between anticipated dosage and adverse event may be resolved through targeted transport by biomaterials and get therapeutic effects through pathological progression via regulation of ROS. Besides, biomaterials fix delivery issues by promoting the penetration of drugs across the blood-brain barrier (BBB), protecting the drug from peripheral degradation, and elevating bioavailability. The goal is to comprehensively understand the mechanisms of ROS in the progression of AD disease and the potential of ROS-related biomaterials in the treatment of AD. This review focuses on OS and its connection with AD and novel biomaterials in recent years against AD via OS to inspire novel biomaterial development. Revisiting these biomaterials and mechanisms associated with OS in AD via thorough investigations presents a considerable potential and bright future for improving effective interventions for AD.

Micro/nanosystems for controllable drug delivery to the brain

Drug delivery to the brain is crucial in the treatment for central nervous system disorders. While significant progress has been made in recent years, there are still major challenges in achieving controllable drug delivery to the brain. Unmet clinical needs arise from various factors, including controlled drug transport, handling large drug doses, methods for crossing biological barriers, the use of imaging guidance, and effective models for analyzing drug delivery. Recent advances in micro/nanosystems have shown promise in addressing some of these challenges. These include the utilization of microfluidic platforms to test and validate the drug delivery process in a controlled and biomimetic setting, the development of novel micro/nanocarriers for large drug loads across the blood-brain barrier, and the implementation of micro-intervention systems for delivering drugs through intraparenchymal or peripheral routes. In this article, we present a review of the latest developments in micro/nanosystems for controllable drug delivery to the brain. We also delve into the relevant diseases, biological barriers, and conventional methods. In addition, we discuss future prospects and the development of emerging robotic micro/nanosystems equipped with directed transportation, real-time image guidance, and closed-loop control.

Neuronanomedicine for Alzheimer's and Parkinson's disease: Current progress and a guide to improve clinical translation

Neuronanomedicine is an emerging multidisciplinary field that aims to create innovative nanotechnologies to treat major neurodegenerative disorders, such as Alzheimer's (AD) and Parkinson's disease (PD). A key component of neuronanomedicine are nanoparticles, which can improve drug properties and demonstrate enhanced safety and delivery across the blood-brain barrier, a major improvement on existing therapeutic approaches. In this review, we critically analyze the latest nanoparticle-based strategies to modify underlying disease pathology to slow or halt AD/PD progression. We find that a major roadblock for neuronanomedicine translation to date is a poor understanding of how nanoparticles interact with biological systems (i.e., bio-nano interactions), which is partly due to inconsistent reporting in published works. Accordingly, this review makes a set of specific recommendations to help guide researchers to harness the unique properties of nanoparticles and thus realise breakthrough treatments for AD/PD.

Isolinderalactone Ameliorates the Pathology of Alzheimer's Disease by Inhibiting the JNK Signaling Pathway

Neuronal cell damage is a major cause of cognitive impairment in Alzheimer's disease (AD). Multiple factors, such as amyloid deposition, tau hyperphosphorylation, and neuroinflammation, can lead to neuronal cell damage. Therefore, the development of multi-target drugs with broad neuroprotective effects may be an effective strategy for the treatment of AD. Natural products have become an important source of drug discovery because of their good pharmacological activity, multiple targets, and low toxicity. In this study, we screened a natural compound library and found that the fat-soluble sesquiterpene natural compound isolinderalactone (Iso) extracted from the dried root pieces of Lindera aggregata had the ability to alleviate cellular damage induced by β-amyloid-1-42 (Aβ1-42). The role and mechanism of Iso in AD have not yet been reported. Herein, we demonstrated that Iso significantly reduced the level of apoptosis in PC12 cells. Besides, Iso treatment reduced amyloid deposition, neuron apoptosis, and neuroinflammation, ultimately improving the cognitive dysfunction of APP/PS1 (APPswe/PSEN 1dE9) mice. Notably, Iso-10 mg/kg showed superior improved effects in APP/PS1 mice compared with the positive control drug donepezil-5 mg/kg. Mechanistically, the results of RNA sequencing combined with Western blots showed that Iso exerted its therapeutic effect by inhibiting the c-Jun N-terminal kinase (JNK) signaling pathway. Taken together, our findings suggest that Iso is a potential drug candidate for the treatment of AD.

Challenges and progress of neurodrug: bioactivities, production and delivery strategies of nerve growth factor protein

Nerve growth factor (NGF) is a vital cytokine that plays a crucial role in the development and regeneration of the nervous system. It has been extensively studied for its potential therapeutic applications in various neural diseases. However, as a protein drug, limited natural source seriously hinders its translation and clinical applications. Conventional extraction of NGF from mouse submandibular glands has a very high cost and potentially induces immunogenicity; total synthesis and semi-synthesis methods are alternatives, but have difficulty in obtaining correct protein structure; gene engineering of plant cells is thought to be non-immunogenic, bioactive and economical. Meanwhile, large molecular weight, high polarity, and negative electrical charge make it difficult for NGF to cross the blood brain barrier to reach therapeutic targets. Current delivery strategies mainly depend on the adenovirus and cell biodelivery, but the safety and efficacy remain to be improved. New materials are widely investigated for the controllable, safe and precise delivery of NGF. This review illustrates physiological and therapeutic effects of NGF for various diseases. Moreover, new progress in production and delivery technologies for NGF are summarized. Bottlenecks encountered in the development of NGF as therapeutics are also discussed with the countermeasures proposed.

Nanotechnology-empowered therapeutics targeting neurodegenerative diseases

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

Metal Nanoparticles in Alzheimer's Disease

Nanotechnology has emerged in different fields of biomedical application, including lifestyle diseases like diabetes, hypertension, and chronic kidney disease, neurodegenerative diseases like Alzheimer's disease (AD), Parkinson's disease, and different types of cancers. Metal nanoparticles are one of the most used drug delivery systems due to the benefits of their enhanced physicochemical properties as compared to bulk metals. Neurodegenerative diseases are the second most cause affecting mortality worldwide after cancer. Hence, they require the most specific and targeted drug delivery systems for maximum therapeutic benefits. Metal nanoparticles are the preferred drug delivery system, possessing greater blood-brain barrier permeability, biocompatibility, and enhanced bioavailability. But some metal nanoparticles exhibit neurotoxic activity owing to their shape, size, surface charge, or surface modification. This review article has discussed the pathophysiology of AD. The neuroprotective mechanism of gold, silver, selenium, ruthenium, cerium oxide, zinc oxide, and iron oxide nanoparticles are discussed. Again, the neurotoxic mechanisms of gold, iron oxide, titanium dioxide, and cobalt oxide are also included. The neuroprotective and neurotoxic effects of nanoparticles targeted for treating AD are discussed elaborately. The review also focusses on the biocompatibility of metal nanoparticles for targeting the brain in treating AD. The clinical trials and the requirement to develop new drug delivery systems are critically analyzed. This review can show a path for the researchers involved in the brain-targeted drug delivery for AD.

Emerging nanotechnology for Alzheimer's disease: From detection to treatment

Alzheimer's disease (AD), one of the most common chronic neurodegenerative diseases, is characterized by memory impairment, synaptic dysfunction, and character mutations. The pathological features of AD are Aβ accumulation, tau protein enrichment, oxidative stress, and immune inflammation. Since the pathogenesis of AD is complicated and ambiguous, it is still challenging to achieve early detection and timely treatment of AD. Due to the unique physical, electrical, magnetic, and optical properties of nanoparticles (NPs), nanotechnology has shown great potential for detecting and treating AD. This review provides an overview of the latest developments in AD detection via nanotechnology based on NPs with electrochemical sensing, optical sensing, and imaging techniques. Meanwhile, we highlight the important advances in nanotechnology-based AD treatment through targeting disease biomarkers, stem-cell therapy and immunotherapy. Furthermore, we summarize the current challenges and present a promising prospect for nanotechnology-based AD diagnosis and intervention.

Recent progress of nanomedicine in the treatment of Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of memory disruption in elderly subjects, with the prevalence continuing to rise mainly because of the aging world population. Unfortunately, no efficient therapy is currently available for the AD treatment, due to low drug potency and several challenges to delivery, including low bioavailability and the impediments of the blood-brain barrier. Recently, nanomedicine has gained considerable attention among researchers all over the world and shown promising developments in AD treatment. A wide range of nano-carriers, such as polymer nanoparticles, liposomes, solid lipid nanoparticles, dendritic nanoparticles, biomimetic nanoparticles, magnetic nanoparticles, etc., have been adapted to develop successful new treatment strategies. This review comprehensively summarizes the recent advances of different nanomedicine for their efficacy in pre-clinical studies. Finally, some insights and future research directions are proposed. This review can provide useful information to guide the future design and evaluation of nanomedicine in AD treatment.

Brain targeted peptide-functionalized chitosan nanoparticles for resveratrol delivery: Impact on insulin resistance and gut microbiota in obesity-related Alzheimer's disease

The pathology of Alzheimer's disease (AD) is highly correlated with obesity-induced insulin resistance. Resveratrol (Res) is a natural phenol that demonstrates a neuroprotective effect, but the bioactivity of Res is low in vivo. Here, chitosan (CS) was cross-linked with sodium tripolyphosphate (TPP) to encapsulate low water solubility Res. Next, a brain-targeted peptide (TG: TGNYKALHPHNG) was modified on the surface of Res-loaded CS/TPP nanoparticles (TG-Res-CS/TPP-NPs) to specifically deliver Res to the brain. Morris water maze results indicated that cognitive impairments were ameliorated by TG-Res-CS/TPP-NPs in obesity-related AD mice. Obesity-related insulin resistance promotes Tau phosphorylation and Aβ aggregation in the brain. Administration of TG-Res-CS/TPP-NPs alleviated lipid deposition-induced insulin resistance and decreased the level of phosphorylated Tau and Aβ aggregation via the JNK/AKT/GSK3β pathway. Additionally, TG-Res-CS/TPP-NPs transported across blood-brain barrier which in turn increased glucose transporter expression levels, antioxidant enzyme activity and inhibited microglial cell activation. Thus, TG-Res-CS/TPP-NPs were more effective than Res-CS/TPP-NPs at regulating glucose homeostasis, oxidative stress and neuroinflammation in the brain. Moreover, inflammatory, lipid metabolism and oxidative stress-related gut microbiota including Helicobacter, Colidextribacter, Anaerotruncus, Parasutterella, Allobaculum, Alloprevotella, Alistipes, Bifidobacterium and Candidatus_Saccharimonas were also regulated by TG-Res-CS/TPP-NPs. This work indicates the potential use of TG-Res-CS/TPP-NPs for the delivery of Res.

Alzheimer's Disease: Innovative Therapeutic Approaches Based on Peptides and Nanoparticles

Alzheimer's disease (AD) is the main cause of dementia in the world and its etiology is not yet fully understood. The pathology of AD is primarily characterized by intracellular neurofibrillary tangles and extracellular amyloid-β plaques. Unfortunately, few treatment options are available, and most treat symptoms, as is the case of acetylcholinesterase inhibitors (IAChE) and N-methyl-d-aspartate receptor antagonists. For more than 20 years pharmaceutical research has targeted the "amyloid cascade hypothesis," but this has not produced meaningful results, leading researchers to focus now on other characteristics of the disease and on multitarget approaches. This review aims to evaluate some new treatments that are being developed and studied. Among these are new treatments based on peptides, which have high selectivity and low toxicity; however, these compounds have a short half-life and encounter challenges when crossing the blood-brain barrier. The present review discusses up-and-coming peptides tested as treatments and explores some nanotechnological strategies to overcome the downsides. These compounds are promising, as they not only act on the symptoms but also aim to prevent progressive neuronal loss.

Tau protein plays a role in the mechanism of cognitive disorders induced by anesthetic drugs

Cognitive disorders are mental health disorders that can affect cognitive ability. Surgery and anesthesia have been proposed to increase the incidence of cognitive dysfunction, including declines in memory, learning, attention and executive function. Tau protein is a microtubule-associated protein located in the axons of neurons and is important for microtubule assembly and stability; its biological function is mainly regulated by phosphorylation. Phosphorylated tau protein has been associated with cognitive dysfunction mediated by disrupting the stability of the microtubule structure. There is an increasing consensus that anesthetic drugs can cause cognitive impairment. Herein, we reviewed the latest literature and compared the relationship between tau protein and cognitive impairment caused by different anesthetics. Our results substantiated that tau protein phosphorylation is essential in cognitive dysfunction caused by anesthetic drugs, and the possible mechanism can be summarized as "anesthetic drugs-kinase/phosphatase-p-Tau-cognitive impairment".

NIR-Assisted MgO-Based Polydopamine Nanoparticles for Targeted Treatment of Parkinson's Disease through the Blood-Brain Barrier

The blood-brain barrier (BBB) is a major limiting factor that prevents the treatment of Parkinson's disease (PD). In the present study, MgOp@PPLP nanoparticles are explored by using MgO nanoparticles as a substrate, polydopamine as a shell, wrapping anti-SNCA plasmid inside, and modifying polyethylene glycol, lactoferrin, and puerarin on the surface to improve the hydrophilicity, brain targeting and antioxidant properties of the particles, respectively. MgOp@PPLP exhibits superior near-infrared radiation (NIR) response. Under the guidance of photothermal effect, these MgOp@PPLP particles are capable of penetrating the BBB and be taken up by neuronal cells to exert gene therapy and antioxidant therapy. In both in vivo and in vitro models of PD, MgOp@PPLP exhibits good neuroprotective effects. Therefore, combined with noninvasive NIR radiation, MgOp@PPLP nanoplatform with good biocompatibility becomes an ideal material to combat neurodegenerative diseases.

Ruthenium-based antitumor drugs and delivery systems from monotherapy to combination therapy

Ruthenium complex is an important compound group for antitumor drug research and development. NAMI-A, KP1019, TLD1433 and other ruthenium complexes have entered clinical research. In recent years, the research on ruthenium antitumor drugs has not been limited to single chemotherapy drugs; other applications of ruthenium complexes have emerged such as in combination therapy. During the development of ruthenium complexes, drug delivery forms of ruthenium antitumor drugs have also evolved from single-molecule drugs to nanodrug delivery systems. The review summarizes the following aspects: (1) ruthenium complexes from monotherapy to combination therapy, including the development of single-molecule compounds, carrier nanomedicine, and self-assembly of carrier-free nanomedicine; (2) ruthenium complexes in the process of ADME in terms of absorption, distribution, metabolism and excretion; (3) the applications of ruthenium complexes in combination therapy, including photodynamic therapy (PDT), photothermal therapy (PTT), photoactivated chemotherapy (PACT), immunotherapy, and their combined application; (4) the future prospects of ruthenium-based antitumor drugs.

Brain-Targeted Biomimetic Nanodecoys with Neuroprotective Effects for Precise Therapy of Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the gradual loss of dopaminergic neurons in the substantia nigra and the accumulation of α-synuclein aggregates called Lewy bodies. Here, nanodecoys were designed from a rabies virus polypeptide with a 29 amino acid (RVG29)-modified red blood cell membrane (RBCm) to encapsulate curcumin nanocrystals (Cur-NCs), which could effectively protect dopaminergic neurons. The RVG29-RBCm/Cur-NCs nanodecoys effectively escaped from reticuloendothelial system (RES) uptake, enabled prolonged blood circulation, and enhanced blood-brain barrier (BBB) crossing after systemic administration. Cur-NCs loaded inside the nanodecoys exhibited the recovery of dopamine levels, inhibition of α-synuclein aggregation, and reversal of mitochondrial dysfunction in PD mice. These findings indicate the promising potential of biomimetic nanodecoys in treating PD and other neurodegenerative diseases.

Non-Invasive Thermal Therapy for Tissue Engineering and Regenerative Medicine

Owing to the development of nanotechnology and noninvasive treatment, thermal therapy in combination with external stimuli has been applied for tissue engineering and regenerative medicine (TERM), which has attracted more and more attention in recent years. In this review, the recent progress of applying a variety of non-invasive thermal therapeutic modalities for TERM, including photothermal therapy, magnetic thermotherapy, and ultrasound thermotherapy, as well as other thermal therapeutics are discussed. The parameters and conditions that need to be considered and regulated to realize a well-controlled thermal therapy for tissue regeneration are also discussed. Afterwards, the current concerns and challenges of putting thermal therapy into clinical applications are pointed out. At last, perspectives are provided for the future development directions, aiming to providing opportunities and a novel pathway for TERM.

PINK1 overexpression prevents forskolin-induced tau hyperphosphorylation and oxidative stress in a rat model of Alzheimer's disease

PTEN-induced putative kinase 1 (PINK1)/parkin pathway mediates mitophagy, which is a specialized form of autophagy. Evidence shows that PINK1 can exert protective effects against stress-induced neuronal cell death. In the present study we investigated the effects of PINK1 overexpression on tau hyperphosphorylation, mitochondrial dysfunction and oxidative stress in a specific rat model of tau hyperphosphorylation. We showed that intracerebroventricular (ICV) microinjection of forskolin (FSK, 80 μmol) induced tau hyperphosphorylation in the rat brain and resulted in significant spatial working memory impairments in Y-maze test, accompanied by synaptic dysfunction (reduced expression of synaptic proteins synaptophysin and postsynaptic density protein 95), and neuronal loss in the hippocampus. Adeno-associated virus (AAV)-mediated overexpression of PINK1 prevented ICV-FSK-induced cognition defect and pathological alterations in the hippocampus, whereas PINK1-knockout significantly exacerbated ICV-FSK-induced deteriorated effects. Furthermore, we revealed that AAV-PINK1-mediated overexpression of PINK1 alleviated ICV-FSK-induced tau hyperphosphorylation by restoring the activity of PI3K/Akt/GSK3β signaling. PINK1 overexpression reversed the abnormal changes in mitochondrial dynamics, defective mitophagy, and decreased ATP levels in the hippocampus. Moreover, PINK1 overexpression activated Nrf2 signaling, thereby increasing the expression of antioxidant proteins and reducing oxidative damage. These results suggest that PINK1 deficiency exacerbates FSK-induced tau pathology, synaptic damage, mitochondrial dysfunction, and antioxidant system defects, which were reversed by PINK1 overexpression. Our data support a critical role of PINK1-mediated mitophagy in controlling mitochondrial quality, tau hyperphosphorylation, and oxidative stress in a rat model of Alzheimer's disease.

Ultrasmall Coordination Polymers for Alleviating ROS-Mediated Inflammatory and Realizing Neuroprotection against Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease globally, and there is currently no effective treatment for this condition. Excessive accumulation of reactive oxygen species (ROS) and neuroinflammation are major contributors to PD pathogenesis. Herein, ultrasmall nanoscale coordination polymers (NCPs) coordinated by ferric ions and natural product curcumin (Cur) were exploited, showing efficient neuroprotection by scavenging excessive radicals and suppressing neuroinflammation. In a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse PD model, such ultrasmall Fe-Cur NCPs with prolonged blood circulation and BBB traversing capability could effectively alleviate oxidative stress, mitochondrial dysfunction, and inflammatory condition in the midbrain and striatum to reduce PD symptoms. Thus, this study puts forth a unique type of therapeutics-based NCPs that could be used for safe and efficient treatment of PD with potential in clinical translation.

"Drug-Carrier" Synergy Therapy for Amyloid-β Clearance and Inhibition of Tau Phosphorylation via Biomimetic Lipid Nanocomposite Assembly

Amyloid-β (Aβ) toxicity is considered to be companioned by Tau phosphorylation in Alzheimer's disease (AD). The clinical AD therapy is usually subjected to low blood-brain barrier (BBB) penetration and complex interaction mechanisms between Aβ and phosphorylated Tau. A "Drug-Carrier" synergy therapy is herein designed to simultaneously target Aβ and Tau-associated pathways for AD treatment. To imitate natural nanoparticle configuration, the endogenous apolipoprotein A-I and its mimicking peptide 4F fused angiopep-2 (Ang) are sequentially grafted onto lipid nanocomposite (APLN), providing liberty of BBB crossing and microglia targeted Aβ clearance. For synergy treatment, methylene blue (MB) is further assembled into APLN (APLN/MB) for Tau aggregation inhibition. After intravenous administration, the optimized density (5 wt%) of Ang ligands dramatically enhances APLN/MB intracerebral shuttling and accumulation, which is 2.15-fold higher than that Ang absent-modification. The site-specific release of MB collaborates APLN to promote Aβ capture for microglia endocytosis clearance and reduce p-Tau level by 25.31% in AD pathogenesis. In AD-Aβ-Tau bearing mouse models, APLN/MB can relieve AD symptoms, rescue neuron viability and cognitive functions. Collectively, it is confirmed that "Drug-Carrier" synergy therapy of APLN/MB is a promising approach in the development of AD treatments.

Anti-Parkinsonian Therapy: Strategies for Crossing the Blood-Brain Barrier and Nano-Biological Effects of Nanomaterials

Parkinson's disease (PD), a neurodegenerative disease that shows a high incidence in older individuals, is becoming increasingly prevalent. Unfortunately, there is no clinical cure for PD, and novel anti-PD drugs are therefore urgently required. However, the selective permeability of the blood-brain barrier (BBB) poses a huge challenge in the development of such drugs. Fortunately, through strategies based on the physiological characteristics of the BBB and other modifications, including enhancement of BBB permeability, nanotechnology can offer a solution to this problem and facilitate drug delivery across the BBB. Although nanomaterials are often used as carriers for PD treatment, their biological activity is ignored. Several studies in recent years have shown that nanomaterials can improve PD symptoms via their own nano-bio effects. In this review, we first summarize the physiological features of the BBB and then discuss the design of appropriate brain-targeted delivery nanoplatforms for PD treatment. Subsequently, we highlight the emerging strategies for crossing the BBB and the development of novel nanomaterials with anti-PD nano-biological effects. Finally, we discuss the current challenges in nanomaterial-based PD treatment and the future trends in this field. Our review emphasizes the clinical value of nanotechnology in PD treatment based on recent patents and could guide researchers working in this area in the future.

Recent Advances in the Treatment of Alzheimer's Disease Using Nanoparticle-Based Drug Delivery Systems

Alzheimer's disease (AD) is an irreversible and progressive neurodegenerative disorder. Most existing treatments only provide symptomatic solutions. Here, we introduce currently available commercial drugs and new therapeutics, including repositioned drugs, to treat AD. Despite tremendous efforts, treatments targeting the hallmarks of AD show limited efficacy. Challenges in treating AD are partly caused by difficulties in penetrating the blood-brain barrier (BBB). Recently, nanoparticle (NP)-based systems have shown promising potential as precision medicines that can effectively penetrate the BBB and enhance the targeting ability of numerous drugs. Here, we describe how NPs enter the brain by crossing, avoiding, or disrupting the BBB. In addition, we provide an overview of the action of NPs in the microenvironment of the brain for the treatment of AD. Diverse systems, including liposomes, micelles, polymeric NPs, solid-lipid NPs, and inorganic NPs, have been investigated for NP drug loading to relieve AD symptoms, target AD hallmarks, and target moieties to diagnose AD. We also highlight NP-based immunotherapy, which has recently gained special attention as a potential treatment option to disrupt AD progression. Overall, this review focuses on recently investigated NP systems that represent innovative strategies to understand AD pathogenesis and suggests treatment and diagnostic modalities to cure AD.

Tau Toxicity in Neurodegeneration

Tau is a microtubule-associated protein widely distributed in the central nervous system (CNS). The main function of tau is to promote the assembly of microtubules and stabilize their structure. After a long period of research on neurodegenerative diseases, the function and dysfunction of the microtubule-associated protein tau in neurodegenerative diseases and tau neurotoxicity have attracted increasing attention. Tauopathies are a series of progressive neurodegenerative diseases caused by pathological changes in tau, such as abnormal phosphorylation. The pathological features of tauopathies are the deposition of abnormally phosphorylated tau proteins and the aggregation of tau proteins in neurons. This article first describes the normal physiological function and dysfunction of tau proteins and then discusses the enzymes and proteins involved in tau phosphorylation and dephosphorylation, the role of tau in cell dysfunction, and the relationships between tau and several neurodegenerative diseases. The study of tau neurotoxicity provides new directions for the treatment of tauopathies.

Gold Nanorods with Spatial Separation of CeO2 Deposition for Plasmonic-Enhanced Antioxidant Stress and Photothermal Therapy of Alzheimer's Disease

Activities of catalase (CAT) and superoxide dismutase (SOD) of ceria nanoparticles (CeO₂ NPs) provide the possibility for their application in nervous system oxidative stress diseases including Alzheimer's disease (AD). The addition of hot electrons produced by a plasma photothermal effect can expand the photocatalytic activity of CeO₂ to the near-infrared region (NIR), significantly improving its redox performance. Therefore, we coated both ends of gold nanorods (Au NRs) with CeO₂ NPs, and photocatalysis and photothermal therapy in the NIR are introduced into the treatment of AD. Meanwhile, the spatially separate structure enhances the catalytic performance and photothermal conversion efficiency. In addition, the photothermal effect significantly improves the permeability of the blood-brain barrier (BBB) and overcomes the shortcomings of traditional anti-AD drugs. To further improve the therapeutic efficiency, Aβ-targeted inhibitory peptides were modified on the middle surface of gold nanorods to synthesize KLVFF@Au-CeO₂ (K-CAC) nanocomposites. We have verified their biocompatibility and therapeutic effectiveness at multiple levels in vitro and in vivo, which have a profound impact on the research and clinical transformation of nanotechnology in AD therapy.

Nano-Honokiol ameliorates the cognitive deficits in TgCRND8 mice of Alzheimer's disease via inhibiting neuropathology and modulating gut microbiota

Introduction

Honokiol (HO) exerts neuroprotective effects in several animal models of Alzheimer's disease (AD), but the poor dissolution hampers its bioavailability and therapeutic efficacy.

Objectives

A novel honokiol nanoscale drug delivery system (Nano-HO) with smaller size and excellent stability was developed in this study to improve the solubility and bioavailability of HO. The anti-AD effects of Nano-HO was determined.

Methods

Male TgCRND8 mice were daily orally administered Nano-HO or HO at the same dosage (20 mg/kg) for 17 consecutive weeks, followed by assessment of the spatial learning and memory functions using the Morris Water Maze test (MWMT).

Results

Our pharmacokinetic study indicated that the oral bioavailability was greatly improved by Nano-HO. In addition, Nano-HO significantly improved cognitive deficits and inhibited neuroinflammation via suppressing the levels of TNF-α, IL-6 and IL-1β in the brain, preventing the activation of microglia (IBA-1) and astrocyte (GFAP), and reducing β-amyloid (Aβ) deposition in the cortex and hippocampus of TgCRND8 mice. Moreover, Nano-HO was more effective than HO in modulating amyloid precursor protein (APP) processing via suppressing β-secretase, as well as enhancing Aβ-degrading enzymes like neprilysin (NEP). Furthermore, Nano-HO more markedly inhibited tau hyperphosphorylation via decreasing the ratio of p-Tau (Thr 205)/tau and regulating tau-related apoptosis proteins (caspase-3 and Bcl-2). In addition, Nano-HO more markedly attenuated the ratios of p-JNK/JNK and p-35/CDK5, while enhancing the ratio of p-GSK-3β (Ser9)/GSK-3β. Finally, Nano-HO prevented the gut microflora dysbiosis in TgCRND8 mice in a more potent manner than free HO.

Conclusion

Nano-HO was more potent than free HO in improving cognitive impairments in TgCRND8 mice via inhibiting Aβ deposition, tau hyperphosphorylation and neuroinflammation through suppressing the activation of JNK/CDK5/GSK-3β signaling pathway. Nano-HO also more potently modulated the gut microbiota community to protect its stability than free HO. These results suggest that Nano-HO has good potential for further development into therapeutic agent for AD treatment.

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.

Large Amino Acid Mimicking Selenium-Doped Carbon Quantum Dots for Multi-Target Therapy of Alzheimer's Disease

Multi-target intervention and synergistic treatment are critical for the drug development of Alzheimer’s disease (AD) due to its complex and multifactional nature. Oxidative stress and amyloid β peptides (Aβ) accumulation have been recognized as therapeutic targets for AD. Herein, with ability to inhibit Aβ aggregation and the broad-spectrum antioxidant properties, the large amino acid mimicking selenium-doped carbon quantum dots (SeCQDs) are presented as novel nanoagents for multi-target therapy of AD. Compared with the precursor, selenocystine, SeCQDs which maintain the intrinsic properties of both selenium and carbon quantum dots (CQDs) possess good biocompatibility and a remarkable ROS-scavenging activity. Moreover, the functionalized α-carboxyl and amino groups on edge of SeCQDs can trigger multivalent interactions with Aβ, leading to the ability of SeCQDs to inhibit Aβ aggregation. In vivo study demonstrated that SeCQDs can significantly ameliorate the Aβ induced memory deficits, reduce Aβ accumulation and inhibit neuron degeneration in AD model rats. The versatility of functionalization and potential ability to cross the blood-brain barrier (BBB) make SeCQDs as prospective nanodrugs for treating AD.

Anisotropic scaffolds for peripheral nerve and spinal cord regeneration

The treatment of long-gap (>10 mm) peripheral nerve injury (PNI) and spinal cord injury (SCI) remains a continuous challenge due to limited native tissue regeneration capabilities. The current clinical strategy of using autografts for PNI suffers from a source shortage, while the pharmacological treatment for SCI presents dissatisfactory results. Tissue engineering, as an alternative, is a promising approach for regenerating peripheral nerves and spinal cords. Through providing a beneficial environment, a scaffold is the primary element in tissue engineering. In particular, scaffolds with anisotropic structures resembling the native extracellular matrix (ECM) can effectively guide neural outgrowth and reconnection. In this review, the anatomy of peripheral nerves and spinal cords, as well as current clinical treatments for PNI and SCI, is first summarized. An overview of the critical components in peripheral nerve and spinal cord tissue engineering and the current status of regeneration approaches are also discussed. Recent advances in the fabrication of anisotropic surface patterns, aligned fibrous substrates, and 3D hydrogel scaffolds, as well as their in vitro and in vivo effects are highlighted. Finally, we summarize potential mechanisms underlying the anisotropic architectures in orienting axonal and glial cell growth, along with their challenges and prospects.

Oral Administration of Resveratrol-Selenium-Peptide Nanocomposites Alleviates Alzheimer's Disease-like Pathogenesis by Inhibiting Aβ Aggregation and Regulating Gut Microbiota

Alzheimer's disease (AD) is a neurodegenerative disease associated with amyloid-β (Aβ) deposition, leading to neurotoxicity (oxidative stress and neuroinflammation) and gut microbiota imbalance. Resveratrol (Res) has neuroprotective properties, but its bioavailability in vivo is very low. Herein, we developed a small Res-selenium-peptide nanocomposite to enable the application of Res for eliminating Aβ aggregate-induced neurotoxicity and mitigating gut microbiota disorder in aluminum chloride (AlCl3) and d-galactose(d-gal)-induced AD model mice. Res functional selenium nanoparticles (Res@SeNPs) (8 ± 0.34 nm) were prepared first, after which the surface of Res@SeNPs was decorated with a blood-brain barrier transport peptide (TGN peptide) to generate Res-selenium-peptide nanocomposites (TGN-Res@SeNPs) (14 ± 0.12 nm). Oral administration of TGN-Res@SeNPs improves cognitive disorder through (1) interacting with Aβ and decreasing Aβ aggregation, effectively inhibiting Aβ deposition in the hippocampus; (2) decreasing Aβ-induced reactive oxygen species (ROS) and increasing activity of antioxidation enzymes in PC12 cells and in vivo; (3) down-regulating Aβ-induced neuroinflammation via the nuclear factor kappa B/mitogen-activated protein kinase/Akt signal pathway in BV-2 cells and in vivo; and (4) alleviating gut microbiota disorder, particularly with respect to oxidative stress and inflammatory-related bacteria such as Alistipes, Helicobacter, Rikenella, Desulfovibrio, and Faecalibaculum. Thus, we anticipate that Res-selenium-peptide nanocomposites will offer a new potential strategy for the treatment of AD.

Peony seed oil ameliorates neuroinflammation-mediated cognitive deficits by suppressing microglial activation through inhibition of NF-κB pathway in presenilin 1/2 conditional double knockout mice

Chronic neuroinflammation has been shown to exert adverse influences on the pathology of Alzheimer's disease (AD), associated with the release of abundant proinflammatory mediators by excessively activated microglia, causing synaptic dysfunction, neuronal degeneration, and memory deficits. Thus, the prevention of microglial activation-associated neuroinflammation is important target for deterring neurodegenerative disorders. Peony seed oil (PSO) is a new food resource, rich in α-linolenic acid, the precursor of long chain omega-3 polyunsaturated fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, which exhibit anti-inflammatory properties by altering cell membrane phospholipid fatty acid compositions, disrupting lipid rafts, and inhibiting the activation of the proinflammatory transcription factor NF-κB. However, few studies have examined the anti-neuroinflammatory effects of PSO in AD, and the relevant molecular mechanisms remain unclear. Presenilin1/2 conditional double knockout (PS cDKO) mice display obvious AD-like phenotypes, such as neuroinflammatory responses, synaptic dysfunction, and cognitive deficits. Here, we assessed the potential neuroprotective effects of PSO against neuroinflammation-mediated cognitive deficits in PS cDKO using behavioral tests and molecular biologic analyses. Our study demonstrated that PSO suppressed microglial activation and neuroinflammation through the down-regulation of proinflammatory mediators, such as inducible NOS, COX-2, IL-1β, and TNF-α, in the prefrontal cortex and hippocampus of PS cDKO mice. Further, PSO significantly lessened memory impairment by reversing hyperphosphorylated tau and synaptic proteins deficits in PS cDKO mice. Importantly, PSO's therapeutic effects on cognitive deficits were due to inhibiting neuroinflammatory responses mediated by NF-κB signaling pathway. Taken together, PSO may represent an effective dietary supplementation to restrain the neurodegenerative processes of AD.

Near-Infrared Radiation-Assisted Drug Delivery Nanoplatform to Realize Blood-Brain Barrier Crossing and Protection for Parkinsonian Therapy

Mitochondrial dysfunction, which is directly involved in Parkinson's disease (PD), is characterized by the production of reactive oxygen species (ROS) and aberrant energy metabolism. Thus, regulating mitochondrial function might be an effective strategy to treat PD. However, the blood-brain barrier (BBB) presents a significant challenge for the intracerebral delivery of drugs. Here, we synthesized a zeolitic imidazolate framework 8-coated Prussian blue nanocomposite (ZIF-8@PB), which was encapsulated with quercetin (QCT), a natural antioxidant, to treat PD. ZIF-8@PB-QCT exhibited superior near-infrared radiation (NIR) response and penetrated through the BBB to the site of mitochondrial damage guided by the photothermal effect. In the mice model of PD, the QCT released from ZIF-8@PB-QCT significantly increased the adenosine triphosphate levels, reduced the oxidative stress levels, and reversed dopaminergic neuronal damage as well as PD-related behavioral deficits without any damage to the normal tissues. Furthermore, we explored the underlying neuroprotective mechanism of ZIF-8@PB-QCT that was mediated by activating the PI3K/Akt signaling pathway. Thus, combined with noninvasive NIR radiation, the biocompatible ZIF-8@PB-QCT nanocomposite could be used to treat neurodegenerative diseases.

Nanoparticles with Multiple Enzymatic Activities Purified from Groundwater Efficiently Cross the Blood-Brain Barrier, Improve Memory, and Provide Neuroprotection

Many engineered nanomaterials (ENMs) and drugs have been fabricated to improve memory and promote neuroprotection, but their use remains challenging due to their high cost, poor ability to penetrate the blood-brain barrier (BBB), and many side effects. Herein, we found that nanoparticles with multiple enzymatic activities purified from groundwater (NMEGs) can efficiently cross the BBB and present memory-enhancing and neuroprotective effects in vitro and in vivo. In contrast to the adverse effects of chemicals and ENMs, NMEGs are able to cross the BBB by endocytosis without damaging the BBB and even possibly promote BBB integrity. NMEGs-treated normal mice were smarter and better behaved than saline-treated normal mice in the open-field test and Morris water maze test. NMEGs can enhance synaptic transmission by increasing neurotransmitter production and activating nicotinic acetylcholine receptors (nAChRs), activate the antioxidant enzyme system, and increase the number of mitochondria and ribosomes in cells. Intravenous NMEGs injection also rescued memory deficits and increased antioxidant capacity in Parkinson's disease (PD) mice due to the antioxidant activity caused by the presence of conjugated double bonds and abundant phenolic -OH groups. This study is a proof-of-principle demonstration that natural products are less expensive, more easily available, safer, and more effective ways to improve memory and promote neuroprotection than ENMs and reported drugs. Our article also shows the potential of NMEGs as a PD treatment in patients via intravenous injection, as they avoid the complex modifications of ENMs. In the future, it will be possible to treat PD by intravenously injecting NMEGs in patients.

Photothermal and Photodynamic Therapies via NIR-Activated Nanoagents in Combating Alzheimer's Disease

It is well established that the polymerization of amyloid-β peptides into fibrils/plaques is a critical step during the development of Alzheimer's disease (AD). Phototherapy, which includes photodynamic therapy and photothermal therapy, is a highly attractive strategy in AD treatment due to its merits of operational flexibility, noninvasiveness, and high spatiotemporal resolution. Distinct from traditional chemotherapies or immunotherapies, phototherapies capitalize on the interaction between photosensitizers or photothermal transduction agents and light to trigger photochemical reactions to generate either reactive oxygen species or heat effects to modulate Aβ aggregation, ultimately restoring nerve damage and ameliorating memory deficits. In this Review, we provide an overview of the recent advances in the development of near-infrared-activated nanoagents for AD phototherapies and discuss the potential challenges of and perspectives on this emerging field with a special focus on how to improve the efficiency and utility of such treatment. We hope that this Review will spur preclinical research and the clinical translation of AD treatment through phototherapy.

Integrated nanomaterials for non-invasive photothermal therapy of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease that causes swelling, redness, and arthralgia of multiple joints. Despite significant research and development on the treatment modalities for RA, there is still no established effective treatment option for eradicating joint damage and inflammation. In recent years, photothermal therapy (PTT) has emerged as a practical approach to treat RA. In this review, we outline various factors that affect the effective treatment of RA. Moreover, we discuss various PTT-based nanomaterials that can be used to treat RA.

Mitochondrial dysfunction: A potential target for Alzheimer's disease intervention and treatment

Alzheimer's disease (AD) is an irreversible neurodegenerative brain disorder which manifests as a progressive decline in cognitive function. Mitochondrial dysfunction plays a critical role in the early stages of AD, and advances the progression of this age-related neurodegenerative disorder. Therefore, it can be a potential target for interventions to treat AD. Several therapeutic strategies to target mitochondrial dysfunction have gained significant attention in the preclinical stage, but the clinical trials performed to date have shown little progress. Thus, we discuss the mechanisms and strategies of different therapeutic agents for targeting mitochondrial dysfunction in AD. We hope that this review will inspire and guide the development of efficient AD drugs in the future.

Photoresponsive materials for intensified modulation of Alzheimer's amyloid-β protein aggregation: A review

The abnormal self-assembly of amyloid-β protein (Aβ) into toxic aggregates is a major pathological hallmark of Alzheimer's disease (AD). Modulation of Aβ fibrillization with pharmacological modalities has become an active field of research, which aims to mitigate Aβ-induced neurotoxicity and ameliorate impaired recognition. Among the various strategies for AD treatment, phototherapy, including photothermal therapy (PTT), photodynamic therapy (PDT), and photoresponsive release systems have attracted increased attention because of the spatiotemporal controllability. Under the irradiation of light, the heat or reactive oxygen species generated by photothermal or photodynamic processes significantly enhances the efficacy of the inhibitor or modulator, and the "caged" drug can be accurately released at the intended site, thus avoiding adverse effects. This review, from a viewpoint of materials, focuses on the recent advances in modulating Aβ aggregation by light that irradiates on the materials that function on modulating Aβ aggregation. Representative examples of PTT, PDT, and photoresponsive drug release systems are discussed in terms of inhibitory mechanism, the unique properties of materials, and the design of modulators. The major challenges of phototherapy against AD are addressed and the promising prospects are proposed. It is concluded that the noninvasive light-assisted approaches will become a promising strategy for intensifying the modulation of Aβ aggregation and thus facilitating AD treatment. STATEMENT OF SIGNIFICANCE: Alzheimer's disease (AD) with the hallmark of amyloid-β protein (Aβ) deposition is affecting more than 50 million people globally. It is urgent to explore intelligent materials to modulate Aβ aggregation. This review summarizes the intensified modulation of Aβ aggregation by a variety of photoresponsive materials including photothermal, photosensitizing and photoresponsive release materials, focusing on their characteristics and functionalities. We believe this review would arouse more interest in the research field of stimuli-responsive materials and promote their clinical applications in AD therapy.

Biomaterials in treatment of Alzheimer's disease

Alzheimer's disease (AD) is a non-recoverable progressive neurodegenerative disorder most prevalent but not limited to the old age population. After all the scientific efforts, there are still many unmet criteria and loopholes in available treatment and diagnostic strategies, limiting their efficacy. The poor drug efficacy is attributed to various biological hurdles, including blood-brain barrier (BBB) and peripheral side effects as most prominent ones and the lack of promising carriers to precisely deliver the drug to the brain by conserving its therapeutic potency. The increasing disease prevalence and unavailability of effective therapy calls for developing a more innovative, convenient and affordable way to treat AD. To fulfill such need, researchers explored various biomaterials to develop potential vectors or other forms to target the bioactives in the brain by preserving their inherent properties, improving the existing lacuna like poor solubility, permeability and bioavailability etc. and minimize the side effect. The unique characteristic properties of biomaterials are used to develop different drug carriers, surface modifying target active ligands, functional carriers, drug conjugate, biosensing probe, diagnostic tool and many more. The nanoparticulate system and other colloidal carriers like hydrogel and biodegradable scaffold can effectively target the drug moieties to the brain. Also, the use of different target-acting ligands and stimuli-responsive carriers assures the site-specificity and controlled release at the desired site by interaction with receptors and various exo- and endogenous stimuli. This review article has highlighted the application of biomaterials for targeting the drug to the brain and as promising diagnostic tools to detect the markers for better AD management. The work particularly focuses on the use of biomaterials as smart drug carriers including pH, thermo, photo, electro and magnetically triggered system; novel drug carriers for brain targeting including polymeric carriers (polymeric nanoparticle, dendrimer and polymeric micelle); lipid carrier (liposome, nanoemulsion, NLC and SLN); inorganic nanoparticles (quantum dots, gold nanoparticles etc.); and other drug vectors (hydrogel, biodegradable scaffold, and carbon nanotube) in treatment of AD. It also highlighted the application of some novel carrier systems and biomaterials as biosensor and other diagnostic tools for early and precise AD diagnosis.

BAY 73-6691 Alters Neuron Plasticity and Phosphorylation of Tau Through Regulation of Cyclic Guanosine Monophosphate/Protein Kinase G/Cyclic Adenosine Monophosphate Response Element-Binding Protein Pathway

Alzheimer’s disease (AD) is one of neurodegenerative diseases characterized by cognitive and memory decline, accompanying with neurofibrillary tangles (NFTs) made of hyperphosphorylated tau protein and senile plaques (SP) accumulated by β-amyloid protein (Aβ). BAY 73-6691, an inhibitor of phosphodiesterase-9 (PDE-9), can improve learning and memory of elderly rats. However, the effects of BAY 73-6691 on neuroapoptotic and neuroinflammatory events, as well as synaptic plasticity of differentiated PC12 cells are remain unclear. In this work, we screened apoptotic cells induced by Aβ25-35 via flow cytometry. TNF-α, IL-1β, IL-6 secreted by PC12 cells were estimated by ELISA kits. The levels of cGMP, PKG and CREB mediated by BAY 73-6691 were assessed. Moreover, we conducted western blots analysis to evaluate the phosphorylation of tau and synaptic related proteins. Results showed that BAY 73-6691 could reduce Aβ25-35-triggered neuroapoptosis and neuroinflammation. Phosphorylation of tau was inhibited by BAY 73-6691, whereas sildenafil citrate (SC, an inhibitor of cGMP) partially weakened the effect of BAY 73-6691. Additionally, synaptic plasticity restored by BAY 73-6691 was also suppressed via SC. Taken together, BAY 73-6691 exhibited neuro protective effects, and altered tau phosphorylation as well as synaptic related proteins through cGMP/PKG/CREB pathway.

Advances in Hollow Inorganic Nanomedicines for Photothermal-Based Therapies

Nanotechnology has prompted the development of hollow inorganic nanomedicine. These medicines are now widely investigated as photothermal-based therapies for various diseases due to their high loading capacity, tuneable wavelength, relatively small size and low density. We begin this review with a brief introduction, followed by a summary of the development of imaging-guided photothermal therapy (PTT) for cancer treatment during the last three years (from 2017 to 2020). We then introduce the antibacterial effects of these medicines on some bacterial infections, in which the pathogenic bacteria can be killed by mild photothermal effects, ions and antibiotic release. Other diseases can also be treated using hollow inorganic photothermal agents. Specifically, we discuss the use of PTT for treating Alzheimer's disease, obesity and endometriosis. Finally, we share our perspectives on the current challenges and future prospects of using hollow inorganic materials in clinical PTT for various diseases.

Functional nanoassemblies for the diagnosis and therapy of Alzheimer's diseases

Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects populations around the world. Many therapeutics have been investigated for AD diagnosis and/or therapy, but the efficacy is largely limited by the poor bioavailability of drugs and by the presence of the blood-brain barrier. Recently, the development of nanomedicines enables efficient drug delivery to the brain, but the complex pathological mechanism of AD prevents them from successful treatment. As a type of advanced nanomedicine, multifunctional nanoassemblies self-assembled from nanoscale imaging or therapeutic agents can simultaneously target multiple pathological factors, showing great potential in the diagnosis and therapy of AD. To help readers better understand this emerging field, in this review, we first introduce the pathological mechanisms and the potential drug candidates of AD, as well as the design strategies of nanoassemblies for improving AD targeting efficiency. Moreover, the progress of dynamic nanoassemblies that can diagnose and/or treat AD in response to the endogenous or exogenous stimuli will be described. Finally, we conclude with our perspectives on the future development in this field. The objective of this review is to outline the latest progress of using nanoassemblies to overcome the complex pathological environment of AD for improved diagnosis and therapy, in hopes of accelerating the future development of intelligent AD nanomedicines. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Diagnostic Tools > in vivo Nanodiagnostics and Imaging.