Using near-infrared enhanced thermozyme and scFv dual-conjugated Au nanorods for detection and targeted photothermal 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.

Amyloid-β-targeting immunotherapies for Alzheimer's disease

Recent advances in clinical passive immunotherapy have provided compelling evidence that eliminating amyloid-β (Aβ) slows cognitive decline in Alzheimer's disease (AD). However, the modest benefits and side effects observed in clinical trials indicate that current immunotherapy therapy is not a panacea, highlighting the need for a deeper understanding of AD mechanisms and the significance of early intervention through optimized immunotherapy or immunoprevention. This review focuses on the centrality of Aβ pathology in AD and summarizes recent clinical progress in passive and active immunotherapies targeting Aβ, discussing their lessons and failures to inform future anti-Aβ biotherapeutics design. Various delivery strategies to optimize Aβ-targeting immunotherapies are outlined, highlighting their benefits and drawbacks in overcoming challenges such as poor stability and limited tissue accessibility of anti-Aβ biotherapeutics. Additionally, the perspectives and challenges of immunotherapy and immunoprevention targeting Aβ are concluded in the end, aiming to guide the development of next-generation anti-Aβ immunotherapeutic agents towards improved efficacy and safety.

Nanorod-associated plasmonic circular dichroism monitors the handedness and composition of α-synuclein fibrils from Parkinson's disease models and post-mortem brain

Human full-length (fl) αSyn fibrils, key neuropathological hallmarks of Parkinson's disease (PD), generate intense optical activity corresponding to the surface plasmon resonance of interacting gold nanorods. Herein, we analysed fibril-enriched protein extracts from mouse and human brain samples as well as from SK-N-SH cell lines with or without human fl and C-terminally truncated (Ctt) αSyn overexpression and exposed them to αSyn monomers, recombinant fl αSyn fibrils or Ctt αSyn fibrils. In vitro-generated human recombinant fl and Ctt αSyn fibrils and fibrils purified from SK-N-SH cells with fl or Ctt αSyn overexpression were also analysed using transmission electron microscopy (TEM) to gain insights into the nanorod-fibril complexes. We found that under the same experimental conditions, bisignate circular dichroism (CD) spectra of Ctt αSyn fibrils exhibited a blue-wavelength shift compared to that of fl αSyn fibrils. TEM results supported that this could be attributed to the different properties of nanorods. In our experimental conditions, fibril-enriched PD brain extract broadened the longitudinal surface plasmonic band with a bisignate CD couplet centred corresponding to the absorption band maximum. Plasmonic CD (PCD) couplets of in vivo- and in vitro-generated fibrils displayed sign reversal, suggesting their opposite handedness. Moreover, the incubation of in vitro-generated human recombinant fl αSyn fibrils in mouse brain extracts from αSyn null mice resulted in PCD couplet inversion, indicating that the biological environment may shape the handedness of αSyn fibrils. These findings support that nanorod-based PCD can provide useful information on the composition and features of αSyn fibrils from biological materials.

Research Progress of Novel Inorganic Nanomaterials in the Diagnosis and Treatment of Alzheimer's Disease

The global increase in the number of Alzheimer's disease (AD) patients has posed numerous treatment challenges. Six Food and Drug Administration-approved medications (e.g., donepezil and memantine) have demonstrated some efficacy but are primarily used to alleviate symptoms. The etiology of AD is unknown, and the blood-brain barrier restricts drug penetration, which severely restricts the use of various therapeutic agents. With their high targeting, long-lasting effect, and multifunctionality, inorganic nanomaterials provide a novel approach to the treatment of AD. A review of inorganic nanoparticles in the diagnosis and therapy of AD. This paper reviews the research literature on the use of inorganic nanomaterials in the treatment of AD. Gold nanoparticles, superparamagnetic iron oxide nanoparticles, magnetic nanoparticles, carbon nanotubes, and quantum dots are among the inorganic nanomaterials studied. As knowledge of the origins of AD remains limited, the majority of studies on inorganic nanomaterials have primarily focused on interventions on Aβ proteins. Adjusting and enhancing the properties of these inorganic nanomaterials, such as core-shell structure design and surface modification, confer benefits for the treatment of AD. Inorganic nanoparticles have a wide spectrum of therapeutic potential for AD. Despite their potential benefits, however, the safety and translation of inorganic nanomaterials into clinical applications remain formidable obstacles.

Photobiomodulation in experimental models of Alzheimer's disease: state-of-the-art and translational perspectives

Alzheimer's disease (AD) poses a significant public health problem, affecting millions of people across the world. Despite decades of research into therapeutic strategies for AD, effective prevention or treatment for this devastating disorder remains elusive. In this review, we discuss the potential of photobiomodulation (PBM) for preventing and alleviating AD-associated pathologies, with a focus on the biological mechanisms underlying this therapy. Future research directions and guidance for clinical practice for this non-invasive and non-pharmacological therapy are also highlighted. The available evidence indicates that different treatment paradigms, including transcranial and systemic PBM, along with the recently proposed remote PBM, all could be promising for AD. PBM exerts diverse biological effects, such as enhancing mitochondrial function, mitigating the neuroinflammation caused by activated glial cells, increasing cerebral perfusion, improving glymphatic drainage, regulating the gut microbiome, boosting myokine production, and modulating the immune system. We suggest that PBM may serve as a powerful therapeutic intervention for AD.

Tau- and α-synuclein-targeted gold nanoparticles: applications, opportunities, and future outlooks in the diagnosis and therapy of neurodegenerative diseases

The use of nanomaterials in medicine offers multiple opportunities to address neurodegenerative disorders such as Alzheimer's and Parkinson's disease. These diseases are a significant burden for society and the health system, affecting millions of people worldwide without sensitive and selective diagnostic methodologies or effective treatments to stop their progression. In this sense, the use of gold nanoparticles is a promising tool due to their unique properties at the nanometric level. They can be functionalized with specific molecules to selectively target pathological proteins such as Tau and α-synuclein for Alzheimer's and Parkinson's disease, respectively. Additionally, these proteins are used as diagnostic biomarkers, wherein gold nanoparticles play a key role in enhancing their signal, even at the low concentrations present in biological samples such as blood or cerebrospinal fluid, thus enabling an early and accurate diagnosis. On the other hand, gold nanoparticles act as drug delivery platforms, bringing therapeutic agents directly into the brain, improving treatment efficiency and precision, and reducing side effects in healthy tissues. However, despite the exciting potential of gold nanoparticles, it is crucial to address the challenges and issues associated with their use in the medical field before they can be widely applied in clinical settings. It is critical to ensure the safety and biocompatibility of these nanomaterials in the context of the central nervous system. Therefore, rigorous preclinical and clinical studies are needed to assess the efficacy and feasibility of these strategies in patients. Since there is scarce and sometimes contradictory literature about their use in this context, the main aim of this review is to discuss and analyze the current state-of-the-art of gold nanoparticles in relation to delivery, diagnosis, and therapy for Alzheimer's and Parkinson's disease, as well as recent research about their use in preclinical, clinical, and emerging research areas.

Multifunctional Nanocarriers for Alzheimer's Disease: Befriending the Barriers

Neurodegenerative diseases (NDDs) have been increasing in incidence in recent years and are now widespread worldwide. Neuronal death is defined as the progressive loss of neuronal structure or function which is closely associated with NDDs and represents the intrinsic features of such disorders. Amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's, Parkinson's, and Huntington's diseases (AD, PD, and HD, respectively) are considered neurodegenerative diseases that affect a large number of people worldwide. Despite the testing of various drugs, there is currently no available therapy that can remedy or effectively slow the progression of these diseases. Nanomedicine has the potential to revolutionize drug delivery for the management of NDDs. The use of nanoparticles (NPs) has recently been developed to improve drug delivery efficiency and is currently subjected to extensive studies. Nanoengineered particles, known as nanodrugs, can cross the blood-brain barrier while also being less invasive compared to the most treatment strategies in use. Polymeric, magnetic, carbonic, and inorganic NPs are examples of NPs that have been developed to improve drug delivery efficiency. Primary research studies using NPs to cure AD are promising, but thorough research is needed to introduce these approaches to clinical use. In the present review, we discussed the role of metal-based NPs, polymeric nanogels, nanocarrier systems such as liposomes, solid lipid NPs, polymeric NPs, exosomes, quantum dots, dendrimers, polymersomes, carbon nanotubes, and nanofibers and surfactant-based systems for the therapy of neurodegenerative diseases. In addition, we highlighted nanoformulations such as N-butyl cyanoacrylate, poly(butyl cyanoacrylate), D-penicillamine, citrate-coated peptide, magnetic iron oxide, chitosan (CS), lipoprotein, ceria, silica, metallic nanoparticles, cholinesterase inhibitors, an acetylcholinesterase inhibitors, metal chelators, anti-amyloid, protein, and peptide-loaded NPs for the treatment of AD.

Extremozyme-Based Biosensors for Environmental Pollution Monitoring: Recent Developments

Extremozymes combine high specificity and sensitivity with the ability to withstand extreme operational conditions. This work presents an overview of extremozymes that show potential for environmental monitoring devices and outlines the latest advances in biosensors utilizing these unique molecules. The characteristics of various extremozymes described so far are presented, underlining their stability and operational conditions that make them attractive for biosensing. The biosensor design is discussed based on the detection of photosynthesis-inhibiting herbicides as a case study. Several biosensors for the detection of pesticides, heavy metals, and phenols are presented in more detail to highlight interesting substrate specificity, applications or immobilization methods. Compared to mesophilic enzymes, the integration of extremozymes in biosensors faces additional challenges related to lower availability and high production costs. The use of extremozymes in biosensing does not parallel their success in industrial applications. In recent years, the "collection" of recognition elements was enriched by extremozymes with interesting selectivity and by thermostable chimeras. The perspectives for biosensor development are exciting, considering also the progress in genetic editing for the oriented immobilization of enzymes, efficient folding, and better electron transport. Stability, production costs and immobilization at sensing interfaces must be improved to encourage wider applications of extremozymes in biosensors.

Selective enhanced cytotoxicity of amino acid deprivation for cancer therapy using thermozyme functionalized nanocatalyst

BACKGROUND

Enzyme therapy based on differential metabolism of cancer cells has demonstrated promising potential as a treatment strategy. Nevertheless, the therapeutic benefit of reported enzyme drugs is compromised by their uncontrollable activity and weak stability. Additionally, thermozymes with high thermal-stability suffer from low catalytic activity at body temperature, preventing them from functioning independently.

RESULTS

Herein, we have developed a novel thermo-enzymatic regulation strategy for near-infrared (NIR)-triggered precise-catalyzed photothermal treatment of breast cancer. Our strategy enables efficient loading and delivery of thermozymes (newly screened therapeutic enzymes from thermophilic bacteria) via hyaluronic acid (HA)-coupled gold nanorods (GNRs). These nanocatalysts exhibit enhanced cellular endocytosis and rapid enzyme activity enhancement, while also providing biosafety with minimized toxic effects on untargeted sites due to temperature-isolated thermozyme activity. Locally-focused NIR lasers ensure effective activation of thermozymes to promote on-demand amino acid deprivation and photothermal therapy (PTT) of superficial tumors, triggering apoptosis, G1 phase cell cycle arrest, inhibiting migration and invasion, and potentiating photothermal sensitivity of malignancies.

CONCLUSIONS

This work establishes a precise, remotely controlled, non-invasive, efficient, and biosafe nanoplatform for accurate enzyme therapy, providing a rationale for promising personalized therapeutic strategies and offering new prospects for high-precision development of enzyme drugs.

The use of nanoparticles in the treatment of infectious diseases and cancer, dental applications and tissue regeneration: a review

The emergence of nanotechnology as a field of study can be traced back to the 1980s, at which point the means to artificially produce, control, and observe matter on a nanometer level was made viable. Recent advancements in technology have enabled us to extend our reach to the nanoscale, which has presented an unparalleled opportunity to directly target biomolecular interactions. As a result of these developments, there is a drive to arise intelligent nanostructures capable of overcoming the obstacles that have impeded the progress of conventional pharmacological methodologies. After four decades, the gradual amalgamation of bio- and nanotechnologies is initiating a revolution in the realm of disease detection, treatment, and monitoring, as well as unsolved medical predicaments. Although a significant portion of research in the field is still confined to laboratories, the initial application of nanotechnology as treatments, vaccines, pharmaceuticals, and diagnostic equipment has now obtained endorsement for commercialization and clinical practice. The current issue presents an overview of the latest progress in nanomedical strategies towards alleviating antibiotic resistance, diagnosing and treating cancer, addressing neurodegenerative disorders, and an array of applications, encompassing dentistry and tuberculosis treatment. The current investigation also scrutinizes the deployment of sophisticated smart nanostructured materials in fields of application such as regenerative medicine, as well as the management of targeted and sustained release of pharmaceuticals and therapeutic interventions. The aforementioned concept exhibits the potential for revolutionary advancements within the field of immunotherapy, as it introduces the utilization of implanted vaccine technology to consistently regulate and augment immune functions. Concurrently with the endeavor to attain the advantages of nanomedical intervention, it is essential to enhance the unceasing emphasis on nanotoxicological research and the regulation of nanomedications' safety. This initiative is crucial in achieving the advancement in medicine that currently lies within our reach.

Macrophage membrane-encapsulated nitrogen-doped carbon quantum dot nanosystem for targeted treatment of Alzheimer's disease: Regulating metal ion homeostasis and photothermal removal of β-amyloid

The abnormal aggregation of β-amyloid protein (Aβ) is a major contributor to Alzheimer's disease (AD). Cu2+ homeostasis imbalance can lead to the aggregation of Aβ, resulting in cytotoxic oligomers and fibrous aggregates, causing neuroinflammation and nerve cell damage, ultimately leading to AD. In this study, we synthesized nitrogen-doped carbon quantum dot (CQD), and designed a macrophage membrane (RAW-M) encapsulated CQD nanosystem for the first time. The abundant nitrogen-containing groups on the surface of CQD effectively capture excess Cu2+ and inhibit rapid Aβ aggregation. Additionally, the good photothermal properties of CQD dissolve the formed fiber precipitates under near-infrared light (NIR). In vitro and in vivo studies showed that the nanosystem significantly improved BBB permeability under laser irradiation, enhancing its ability to cross the BBB and overcome traditional anti-AD drug limitations. In vivo investigations conducted on APP/PS1 mice indicate that the nanosystem strongly reduced Aβ deposition, mitigated neuroinflammation, and ameliorates deficits in learning and memory. Overall, our nanocarrier approach adjusts metal ion homeostasis, inhibits abnormal Aβ aggregation, and uses excellent photothermal properties to depolymerize mature Aβ fibrils to protect cells from Aβ neurotoxicity, providing an effective strategy for Aβ-targeted treatment of AD.

Peptide-Functionalized Prussian Blue Nanomaterial for Antioxidant Stress and NIR Photothermal Therapy against Alzheimer's Disease

Excessive accumulations of reactive oxygen species (ROS) and amyloid-β (Aβ) protein are closely associated with the complex pathogenesis of Alzheimer's disease (AD). Therefore, approaches that synergistically exert elimination of ROS and dissociation of Aβ fibrils are effective therapeutic strategies for correcting the AD microenvironment. Herein, a novel near infrared (NIR) responsive Prussian blue-based nanomaterial (PBK NPs) is established with excellent antioxidant activity and photothermal effect. PBK NPs possess similar activities to multiple antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase, which can eliminate massive ROS and relieve oxidative stress. Under the NIR irradiation, PBK NPs can generate local heat to disaggregate Aβ fibrils efficiently. By modifying CKLVFFAED peptide, PBK NPs display obvious targeting ability for blood-brain barrier penetration and Aβ binding. Furthermore, in vivo studies demonstrate that PBK NPs have outstanding ability to decompose Aβ plaques and alleviate neuroinflammation in AD mouse model. Overall, PBK NPs provide evident neuroprotection by reducing ROS levels and regulating Aβ deposition, and may accelerate the development of multifunctional nanomaterials for delaying the progression of AD.

Effect of plasmonic excitation on mature insulin amyloid fibrils

Interactions between amyloid protein structures and nanomaterials have been extensively studied to develop effective inhibitors of amyloid aggregation. Limited investigations are reported on the impact of nanoparticles on mature fibrils. In this work, gold nanoparticles are used as photothermal agents to alter insulin fibrils. To this end, gold colloids bearing a negatively charged capping shell, with an average diameter of 14 nm and a plasmon resonance maximum at 520 nm are synthesized. The effects on mature insulin fibril morphology and structure upon plasmonic excitation of the nanoparticles-fibril samples have been monitored by spectroscopic and microscopic methods. The obtained data indicate that an effective destruction of the amyloid aggregates occur upon irradiation of the plasmonic nanoparticles, allowing the development of emerging strategies to alter the structure of amyloid fibrils.

Mechanism Exploration of Amyloid-β-42 Disaggregation by Single-Chain Variable Fragments of Alzheimer's Disease Therapeutic Antibodies

Alzheimer's disease (AD) is a specific neurodegenerative disease. This study adopts single-chain variable fragments (scFvs) as a potential immunotherapeutic precursor for AD. According to the remarkable effects of monoclonal antibodies, such as the depolymerization or promotion of Aβ42 efflux by Crenezumab, Solanezumab, and 12B4, it is attractive to prepare corresponding scFvs targeting amyloid-β-42 protein (Aβ42) and investigate their biological activities. Crenezumab-like scFv (scFv-C), Solanezumab-like scFv (scFv-S), and 12B4-like scFv (scFv-12B4) were designed and constructed. The thermal stabilities and binding ability to Aβ42 of scFv-C, scFv-S, and scFv-12B4 were evaluated using unfolding profile and enzyme-linked immunosorbent assay. As the results indicated that scFv-C could recognize Aβ42 monomer/oligomer and promote the disaggregation of Aβ42 fiber as determined by the Thioflavin-T assay, the potential mechanism of its interaction with Aβ42 was investigated using molecular dynamics analysis. Interactions involving hydrogen bonds and salt bonds were predicted between scFv-C and Aβ42 pentamer, suggesting the possibility of inhibiting further aggregation of Aβ42. The successfully prepared scFvs, especially scFv-C, with favorable biological activity targeting Aβ42, might be developed for a potentially efficacious clinical application for AD.

Advances in photobiomodulation for cognitive improvement by near-infrared derived multiple strategies

Cognitive function is an important ability of the brain, but cognitive dysfunction can easily develop once the brain is injured in various neuropathological conditions or diseases. Photobiomodulation therapy is a type of noninvasive physical therapy that is gradually emerging in the field of neuroscience. Transcranial photobiomodulation has been commonly used to regulate neural activity in the superficial cortex. To stimulate deeper brain activity, advanced photobiomodulation techniques in conjunction with photosensitive nanoparticles have been developed. This review addresses the mechanisms of photobiomodulation on neurons and neural networks and discusses the advantages, disadvantages and potential applications of photobiomodulation alone or in combination with photosensitive nanoparticles. Photobiomodulation and its associated strategies may provide new breakthrough treatments for cognitive improvement.

An NIR-Driven Upconversion/C3N4/CoP Photocatalyst for Efficient Hydrogen Production by Inhibiting Electron-Hole Pair Recombination for Alzheimer's Disease Therapy

Redox imbalance and abnormal amyloid protein (Aβ) buildup are key factors in the etiology of Alzheimer's disease (AD). As an antioxidant, the hydrogen molecule (H₂) has the potential to cure AD by specifically scavenging highly harmful reactive oxygen species (ROS) such as ^•OH. However, due to the low solubility of H₂ (1.6 ppm), the traditional H₂ administration pathway cannot easily achieve long-term and effective accumulation of H₂ in the foci. Therefore, how to achieve the continuous release of H₂ in situ is the key to improve the therapeutic effect on AD. As a corollary, we designed a rare earth ion doped g-C₃N₄ upconversion photocatalyst, which can respond to NIR and realize the continuous production of H₂ by photocatalytic decomposition of H₂O in biological tissue, which avoids the problem of the poor penetration of visible light. The introduction of CoP cocatalyst accelerates the separation and transfer of photogenerated electrons in g-C₃N₄, thus improving the photocatalytic activity of hydrogen evolution reaction. The morphology of the composite photocatalyst was shown by transmission electron microscopy, and the crystal structure was studied by X-ray diffractometry and Raman analysis. In addition, the ability of g-C₃N₄ to chelate metal ions and the photothermal properties of CoP can inhibit Aβ and reduce the deposition of Aβ in the brain. Efficient in situ hydrogen production therapy combined with multitarget synergism solves the problem of a poor therapeutic effect of a single target. In vivo studies have shown that UCNP@CoP@g-C₃N₄ can reduce Aβ deposition, improve memory impairment, and reduce neuroinflammation in AD mice.

Nanomedicine-based immunotherapy for Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease caused by the deposition of amyloid β (Aβ) fibrils forming extracellular plaques and the development of neurofibrillary tangles (NFT) of intracellular hyperphosphorylated tau protein. Currently, the AD treatments focus on improving cognitive and behavioral symptoms and have limited success. It is imperative to develop novel treatment approaches that can control/inhibit AD progression, especially in the elderly population. Immunotherapy provides a promising and safe treatment option for AD by boosting the patient's immune system. The minimum immune surveillance in the immune-privileged brain, however, makes immunotherapy for AD a challenging endeavor. Therefore, the success of AD immunotherapy depends mainly on the strategy by which therapeutics is delivered to the brain rather than its efficacy. The blood-brain barrier (BBB) is a major obstacle to therapeutic delivery into the brain microenvironment. Various nano-formulations have been exploited to improve the efficacy of AD immunotherapy. In this review, the applications of different types of nano-formulations in augmenting AD immunotherapy have been discussed.

Advanced nanomaterials for modulating Alzheimer's related amyloid aggregation

Alzheimer's disease (AD) is a common neurodegenerative disease that brings about enormous economic pressure to families and society. Inhibiting abnormal aggregation of Aβ and accelerating the dissociation of aggregates is treated as an effective method to prevent and treat AD. Recently, nanomaterials have been applied in AD treatment due to their excellent physicochemical properties and drug activity. As a drug delivery platform or inhibitor, various excellent nanomaterials have exhibited potential in inhibiting Aβ fibrillation, disaggregating, and clearing mature amyloid plaques by enhancing the performance of drugs. This review comprehensively summarizes the advantages and disadvantages of nanomaterials in modulating amyloid aggregation and AD treatment. The design of various functional nanomaterials is discussed, and the strategies for improved properties toward AD treatment are analyzed. Finally, the challenges faced by nanomaterials with different dimensions in AD-related amyloid aggregate modulation are expounded, and the prospects of nanomaterials are proposed.

Surface enhanced fluorescence effect improves the in vivo detection of amyloid aggregates

The β-amyloid (Aβ) peptide is one of the key etiological agents in Alzheimer's disease (AD). The in vivo detection of Aβ species is challenging in all stages of the illness. Currently, the development of fluorescent probes allows the detection of Aβ in animal models in the near-infrared region (NIR). However, considering future applications in biomedicine, it is relevant to develop strategies to improve detection of amyloid aggregates using NIR probes. An innovative approach to increase the fluorescence signal of these fluorophores is the use of plasmonic gold nanoparticles (surface-enhanced fluorescence effect). In this work, we improved the detection of Aβ aggregates in C. elegans and mouse models of AD by co-administering functionalized gold nanorods (GNRs-PEG-D1) with the fluorescent probes CRANAD-2 or CRANAD-58, which bind selectively to different amyloid species (soluble and insoluble). This work shows that GNRs improve the detection of Aβ using NIR probes in vivo.

Recent advancements of nanoparticles application in cancer and neurodegenerative disorders: At a glance

Nanoscale engineering is one of the innovative approaches to heal multitudes of ailments, such as varieties of malignancies, neurological problems, and infectious illnesses. Therapeutics for neurodegenerative diseases (NDs) may be modified in aspect because of their ability to stimulate physiological response while limiting negative consequences by interfacing and activating possible targets. Nanomaterials have been extensively studied and employed for cancerous therapeutic strategies since nanomaterials potentially play a significant role in medical transportation. When compared to conventional drug delivery, nanocarriers drug delivery offers various benefits, such as excellent reliability, bioactivity, improved penetration and retention impact, as well as precise targeting and administering. Upregulation of drug efflux transporters, dysfunctional apoptotic mechanisms, and a hypoxic atmosphere are all elements that lead to cancer treatment sensitivity in humans. It has been possible to target these pathways using nanoparticles and increase the effectiveness of multidrug resistance treatments. As innovative strategies of tumor chemoresistance are uncovered, nanomaterials are being developed to target specific pathways of tumor resilience. Scientists have recently begun investigating the function of nanoparticles in immunotherapy, a field that is becoming increasingly useful in the care of malignancies. Nanoscale therapeutics have been explored in this scientific literature and represent the most current approaches to neurodegenerative illnesses and cancer therapy. In addition, current findings and various biomedical nanomaterials' future promise for tissue regeneration, prospective medication design, and the synthesis of novel delivery approaches have been emphasized.

Dopamine D2 and Serotonin 5-HT1A Dimeric Receptor-Binding Monomeric Antibody scFv as a Potential Ligand for Carrying Drugs Targeting Selected Areas of the Brain

Targeted therapy uses multiple ways of ensuring that the drug will be delivered to the desired site. One of these ways is an encapsulation of the drug and functionalization of the surface. Among the many molecules that can perform such a task, the present work focused on the antibodies of single-chain variable fragments (scFvs format). We studied scFv, which specifically recognizes the dopamine D2 and serotonin 5-HT1A receptor heteromers. The scFvD2-5-HT1A protein was analyzed biochemically and biologically, and the obtained results indicated that the antibody is properly folded and non-toxic and can be described as low-immunogenic. It is not only able to bind to the D2-5-HT1A receptor heteromer, but it also influences the cAMP signaling pathway and-when surfaced on nanogold particles-it can cross the blood-brain barrier in in vitro models. When administered to mice, it decreased locomotor activity, matching the effect induced by clozapine. Thus, we are strongly convinced that scFvD2-5-HT1A, which was a subject of the present investigation, is a promising targeting ligand with the potential for the functionalization of nanocarriers targeting selected areas of the brain.

Current Strategies for Real-Time Enzyme Activation

Enzyme activation is a powerful means of achieving biotransformation function, aiming to intensify the reaction processes with a higher yield of product in a short time, and can be exploited for diverse applications. However, conventional activation strategies such as genetic engineering and chemical modification are generally irreversible for enzyme activity, and they also have many limitations, including complex processes and unpredictable results. Recently, near-infrared (NIR), alternating magnetic field (AMF), microwave and ultrasound irradiation, as real-time and precise activation strategies for enzyme analysis, can address many limitations due to their deep penetrability, sustainability, low invasiveness, and sustainability and have been applied in many fields, such as biomedical and industrial applications and chemical synthesis. These spatiotemporal and controllable activation strategies can transfer light, electromagnetic, or ultrasound energy to enzymes, leading to favorable conformational changes and improving the thermal stability, stereoselectivity, and kinetics of enzymes. Furthermore, the different mechanisms of activation strategies have determined the type of applicable enzymes and manipulated protocol designs that either immobilize enzymes on nanomaterials responsive to light or magnetic fields or directly influence enzymatic properties. To employ these effects to finely and efficiently activate enzyme activity, the physicochemical features of nanomaterials and parameters, including the frequency and intensity of activation methods, must be optimized. Therefore, this review offers a comprehensive overview related to emerging technologies for achieving real-time enzyme activation and summarizes their characteristics and advanced applications.

Gold nanostructures: synthesis, properties, and neurological applications

Recent advances in technology are expected to increase our current understanding of neuroscience. Nanotechnology and nanomaterials can alter and control neural functionality in both in vitro and in vivo experimental setups. The intersection between neuroscience and nanoscience may generate long-term neural interfaces adapted at the molecular level. Owing to their intrinsic physicochemical characteristics, gold nanostructures (GNSs) have received much attention in neuroscience, especially for combined diagnostic and therapeutic (theragnostic) purposes. GNSs have been successfully employed to stimulate and monitor neurophysiological signals. Hence, GNSs could provide a promising solution for the regeneration and recovery of neural tissue, novel neuroprotective strategies, and integrated implantable materials. This review covers the broad range of neurological applications of GNS-based materials to improve clinical diagnosis and therapy. Sub-topics include neurotoxicity, targeted delivery of therapeutics to the central nervous system (CNS), neurochemical sensing, neuromodulation, neuroimaging, neurotherapy, tissue engineering, and neural regeneration. It focuses on core concepts of GNSs in neurology, to circumvent the limitations and significant obstacles of innovative approaches in neurobiology and neurochemistry, including theragnostics. We will discuss recent advances in the use of GNSs to overcome current bottlenecks and tackle technical and conceptual challenges.

Bio-fabrication of thermozyme-based nano-biosensors: their components and present scenario

An amalgamation of microbiology, biocatalysis, recombinant molecular biology, and nanotechnology is crucial for groundbreaking innovation in developing nano-biomedicines and sensoristics. Enzyme-based nano-biosensor finds prospective applications in various sectors (environmental, pharmaceutical, food, biorefineries). These applications demand reliable catalytic efficiency and functionality of the enzyme under an extreme operational environment for a prolonged period. Over the last few years, bio-fabrication of nano-biosensors in conjunction with thermozymes from thermophilic microbes is being sought after as a viable design. Thermozymes are known for their robustness, are chemically resistant toward organic solvents, possess higher durability for constant use, catalytic ability, and stability at elevated temperatures. Additionally, several other attributes of thermozymes like substrate specificity, selectivity, and sensitivity make them desirable in developing a customized biosensor. In this review, crucial designing aspects of enzyme-based nano-biosensors like enzyme immobilization on an electrode surface, new materials derived from microbial sources (biopolymers based nanocomposites), improvisation measures for sensitivity, and selectivity have been addressed. It also covers microbial biosynthesis of nanomaterials used to develop sensoristic devices and its numerous applications such as wastewater treatment, biorefineries, and diagnostics. The knowledge will pave the way toward creating consistent eco-friendly, economically viable nanostructured-based technologies with broad applicability and exploitation for industrial use in the near future.

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.

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.

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.

Application of Antibody Fragments Against Aβ With Emphasis on Combined Application With Nanoparticles in Alzheimer's Disease

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases and accumulating evidences suggest a key role of amyloid-β (Aβ) peptide in the pathogenesis of AD. According to the amyloid cascade hypothesis, the imbalance of producing and clearing Aβ is the beginning of neurodegeneration and dementia. Consequently, immunotherapy becomes popular through using antibodies against Aβ. However, many studies of monoclonal antibodies were stopped because adverse effects appeared or there were no evident benefits observed. Some antibody fragments have many advantages over monoclonal antibodies, such as small sizes, lack of the crystallizable fraction (Fc) and so on. There are three main antibody fragments, including single chain variable fragments (scFvs), Fab fragments and single-domain antibody fragments. Nanoparticles can facilitate the entry of drug molecules across the blood-brain barrier, making them become excellent carriers. Various kinds of nanoparticles have been applied in the treatment of AD. The combination of nanoparticles and antibody fragments against amyloid-β can be used in the diagnosis and treatment of Alzheimer’s disease. In this review, we summarize the progress of antibody fragments against amyloid-β in AD, focusing on the combined application with nanoparticles in the diagnosis and treatment of AD.

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.

Graphene oxide improves postoperative cognitive dysfunction by maximally alleviating amyloid beta burden in mice

Rationale: Graphene oxide (GO) based nanomaterials have shown potential for the diagnosis and treatment of amyloid-β (Aβ)-related diseases, mainly on Alzheimer's disease (AD). However, these nanomaterials have limitations. How GO is beneficial to eliminate Aβ burden, and its physiological function in Aβ-related diseases, still needs to be investigated. Moreover, postoperative cognitive dysfunction (POCD) is an Aβ-related common central nervous system complication, however, nanomedicine treatment is lacking.

Methods: To evaluate the effects of GO on Aβ levels, HEK293T-APP-GFP and SHSY5Y-APP-GFP cells are established. Intramedullary fixation surgery for tibial fractures under inhalation anesthesia is used to induce dysfunction of fear memory in mice. The fear memory of mice is assessed by fear conditioning test.

Results: GO treatment maximally alleviated Aβ levels by simultaneously reducing Aβ generation and enhancing its degradation through inhibiting β-cleavage of amyloid precursor protein (APP) and improving endosomal Aβ delivery to lysosomes, respectively. In postoperative mice, the hippocampal Aβ levels were significantly increased and hippocampal-dependent fear memory was impaired. However, GO administration significantly reduced hippocampal Aβ levels and improved the cognitive function of the postoperative mice.

Conclusion: GO improves fear memory of postoperative mice by maximally alleviating Aβ accumulation, providing new evidence for the application of GO-based nanomedicines in Aβ-related diseases.

Active Cellular and Subcellular Targeting of Nanoparticles for Drug Delivery

Nanoparticle (NP)-mediated drug delivery (NMDD) for active targeting of diseases is a primary goal of nanomedicine. NPs have much to offer in overcoming the limitations of traditional drug delivery approaches, including off-target drug toxicity and the need for the administration of repetitive doses. In the last decade, one of the main foci in NMDD has been the realization of NP-mediated drug formulations for active targeted delivery to diseased tissues, with an emphasis on cellular and subcellular targeting. Advances on this front have included the intricate design of targeted NP-drug constructs to navigate through biological barriers, overcome multidrug resistance (MDR), decrease side effects, and improve overall drug efficacy. In this review, we survey advancements in NP-mediated drug targeting over the last five years, highlighting how various NP-drug constructs have been designed to achieve active targeted delivery and improved therapeutic outcomes for critical diseases including cancer, rheumatoid arthritis, and Alzheimer's disease. We conclude with a survey of the current clinical trial landscape for active targeted NP-drug delivery and how we envision this field will progress in the near future.

Near-Infrared Light-Enhanced Protease-Conjugated Gold Nanorods As A Photothermal Antimicrobial Agent For Elimination Of Exotoxin And Biofilms

Purpose

Treatment strategies to eliminate bacterial infections have long emphasized bacterial killing as a goal. However, bacteria secrete toxins that sustain chronic disease and dead cells release DNA that can promote the spread of antibiotic resistance even when viable cells are eradicated. Meanwhile, biofilms regulated by quorum-sensing system, protect bacteria and promote the development of antibiotic resistance. Thus, all of these factors underscore the need for novel antimicrobial therapeutic treatments as alternatives to traditional antibiotics. Here, a smart material was developed that incorporated gold nanorods and an adsorbed protease (protease-conjugated gold nanorods, PGs). When illuminated with near-infrared (NIR) light, PGs functioned to physically damage bacteria, prevent biofilm and exotoxin production, eliminate pre-existing biofilm and exotoxin, and inhibit bacterial quorum-sensing systems.

Methods

PGs were incubated with suspensions of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria followed by exposure to 808-nm NIR laser irradiation. Bacterial viability was determined using a colony-forming unit assay followed by an exploration of cell-damage mechanisms using transmission electron microscopy, scanning electron microscopy, agarose gel electrophoresis, and SDS-PAGE. Quantification of biofilm mass was performed using crystal violet staining. A commercial enterotoxin ELISA kit was used to test inhibitory and degradative effects of PGs on secreted exotoxin.

Results

Use of the remote-controlled antibacterial system reduced surviving bacterial populations to 3.2% and 2.1% of untreated control numbers for E. coli and S. aureus, respectively, and inhibited biofilm formation and exotoxin secretion even in the absence of NIR radiation. However, enhanced degradation of existing biofilm and exotoxin was observed when PGs were used with NIR laser irradiation.

Conclusion

This promising new strategy achieved both the reduction of viable microorganisms and elimination of biofilm and exotoxin. Thus, this strategy addresses the long-ignored issue of persistence of bacterial residues that perpetuate chronic illness in patients even after viable bacteria have been eradicated.

Multiple Antigenic Peptide System Coupled with Amyloid Beta Protein Epitopes As An Immunization Approach to Treat Alzheimer's Disease

Latest studies suggest that Alzheimer's disease (AD) is one of the "four big killers" that threaten the health of the elderly. AD affects about 46 million people across the world, and there is a critical need for research on new therapies for treating AD. The purpose of the present study was to develop and evaluate immunogens to elicit antibodies against the formation of amyloid beta protein (Aβ), a pathological hallmark of AD, as a therapeutic strategy in AD. In this study, serial potential immunogenic epitopes were screened according to the Aβ sequence. The screened linear epitopes on the Aβ C-terminal fragment were coupled with either the carrier protein keyhole limpet hemocyanin (KLH) or the synthesized 4-branch peptide (MAP₄). MAP₄ immunogens could effectively elicit immunogenicity against Aβ_1-42 monomer and fiber in Balb/C mice. Furthermore, MAP₄ sera could also effectively inhibit the formation of the Aβ_1-42 fiber. Interestingly, one of the MAP₄ sera was able to depolymerize the Aβ_1-42 fibers that had aggregated. The monoclonal antibody, 1H7, was shown to inhibit the formation of Aβ_1-42 fiber. MAP₄ carrier may provide benefits over current immunization strategies, as it does not induce inflammation. In conclusion, the MAP₄-Aβ conjugates offer a promising approach for the development of a safe and effective AD vaccine.