Near-Infrared Light-Powered Janus Nanomotor Significantly Facilitates Inhibition of Amyloid-β Fibrillogenesis

Micro/nanomotors for neuromodulation

Micro-nanomotors (MNMs) are micro/nanoscale intelligent devices with vast potential in the fields of drug delivery, precision medicine, biosensing, and environmental remediation. Their primary advantage lies in their ability to convert various forms of external energy (such as magnetic, ultrasonic, and light energy) into their own propulsive force. Additionally, MNMs offer high controllability and modifiability, enabling them to navigate in the microscopic world. Importantly, recent research has harnessed the unique advantages of MNMs to synergize their capabilities in neuromodulation. This mini-review presents the significant progress and pioneering achievements in the use of MNMs for neuromodulation, with the aim of inspiring readers to explore the broader biomedical applications of these MNMs. Through continuous innovation and diligent exploration, MNMs show promise to have a profound impact on the field of biomedicine.

In-situ growth of CeO2 on biofilms: Innovative nanoparticles for photothermal therapy & multi-pronged attack on Alzheimer's disease

Alzheimer's disease (AD) is complex and multifactorial, and its pathogenesis involves multiple factors and processes. This study pioneered the in situ growth of cerium oxide nanoparticles on macrophage membranes (Ce-RAW). Further, carbon quantum dots (CQD) were biomimetically modified by Ce-RAW, leading to the synthesis of a multifunctional nanocomposite (CQD-Ce-RAW). Within the framework of this research, CQD-Ce-RAW was strategically combined with photothermal therapy (PTT), aiming to achieve a more significant therapeutic effect. The macrophage membrane confers the system with anti-phagocytic and anti-inflammatory biological functions. More importantly, the ultra-small size of cerium oxide grown on the membrane acts as a reactive oxygen species (ROS) scavenger and alleviates the degree of oxidative stress. Meanwhile, CQD as a photosensitizer helps dissociate amyloid-β (Aβ) aggregates and chelates excess copper ions, thus further inhibiting Aβ aggregation. Cell experiments showed that CQD-Ce-RAW combined with PTT could effectively degrade and inhibit the aggregation of Aβ, remove ROS, and improve cell survival rate. The results of in vivo photothermal experiments demonstrated that near-infrared light enhanced the efficiency of drug penetration through the blood-brain barrier and facilitated its accumulation in brain tissue. This comprehensive therapeutic approach can intervene in the disease progression from multiple pathways, providing a new prospect for treating AD.

Putting Hybrid Nanomaterials to Work for Biomedical Applications

Hybrid nanomaterials have found use in many biomedical applications. This article provides a comprehensive review of the principles, techniques, and recent advancements in the design and fabrication of hybrid nanomaterials for biomedicine. We begin with an introduction to the general concept of material hybridization, followed by a discussion of how this approach leads to materials with additional functionality and enhanced performance. We then highlight hybrid nanomaterials in the forms of nanostructures, nanocomposites, metal-organic frameworks, and biohybrids, including their fabrication methods. We also showcase the use of hybrid nanomaterials to advance biomedical engineering in the context of nanomedicine, regenerative medicine, diagnostics, theranostics, and biomanufacturing. Finally, we offer perspectives on challenges and opportunities.

Transthyretin-Penetratin: A Potent Fusion Protein Inhibitor against Alzheimer's Amyloid-β Fibrillogenesis with High Blood Brain Barrier Crossing Capability

The design of a potent amyloid-β protein (Aβ) inhibitor plays a pivotal role in the prevention and treatment of Alzheimer's disease (AD). Despite endogenous transthyretin (TTR) being recognized as an Aβ inhibitor, the weak inhibitory and blood brain barrier (BBB) crossing capabilities hinder it for Aβ aggregation inhibition and transport. Therefore, we have herein designed a recombinant TTR by conjugating a cationic cell penetrating peptide (penetratin, Pen), which not only enabled the fusion protein, TTR-Pen (TP), to present high BBB penetration but also greatly enhanced the potency of Aβ inhibition. Namely, the protein fusion made TP positively charged, leading to a potent suppression of Aβ40 fibrillization at a low concentration (1.5 μM), while a TTR concentration as high as 12.5 μM was required to gain a similar function. Moreover, TP could mitigate Aβ-induced neuronal death, increase cultured cell viability from 72% to 92% at 2.5 μM, and extend the lifespan of AD nematodes from 14 to 18 d. Thermodynamic studies revealed that TP, enriched in positive charges, presented extensive electrostatic interactions with Aβ40. Importantly, TP showed excellent BBB penetration performance, with a 10 times higher BBB permeability than TTR, which would allow TP to enter the brain of AD patients and participate in the transport of Aβ species out of the brain. Thus, it is expected that the fusion protein has great potential for drug development in AD treatment.

Engineered platelet cell motors for boosted cancer radiosensitization

Design of engineered cells to target and deliver nanodrugs to the hard-to-reach regions has become an exciting research area. However, the limited penetration and retention of cell-based carriers in tumor tissue restricted their therapeutic efficiency. Inspired by the enhanced delivery behavior of mobile micro/nanomotors, herein, urease-powered platelet cell motors (PLT@Au@Urease) capable of active locomotion, tumor targeting, and radiosensitizers delivery were designed for boosting radiosensitization. The engineered platelet cell motors were constructed by in situ synthesis and loading of radiosensitizers gold nanoparticles in platelets, and then conjugation with urease as the engine. Under physiological concentration of urea, thrust around PLT@Au@Urease motors can be generated via the biocatalytic reactions of urease, leading to rapid tumor cell targeting and enhanced cellular uptake of radiosensitizers. Encouragingly, in comparison with engineered PLT without propulsion capability (PLT@Au), the self-propelled PLT@Au@Urease motors could significantly increase intracellular ROS level and exacerbate nuclear DNA damage induced by γ-radiation, resulting in a remarkably high sensitization enhancement rate (1.89) than that of PLT@Au (1.08). In vivo experiments with 4 T1-bearing mice demonstrated that PLT@Au@Urease in combination with radiation therapy possessed good antitumor performance. Such an intelligent cell motor would provide a promising approach to enhance radiosensitization and broaden the applications of cell motor-based delivery systems.

Recent Advances in Light-Driven Semiconductor-Based Micro/Nanomotors: Optimization Strategies and Emerging Applications

Micro/nanomotors represent a burgeoning field of research featuring small devices capable of autonomous movement in liquid environments through catalytic reactions and/or external stimuli. This review delves into recent advancements in light-driven semiconductor-based micro/nanomotors (LDSM), focusing on optimized syntheses, enhanced motion mechanisms, and emerging applications in the environmental and biomedical domains. The survey commences with a theoretical introduction to micromotors and their propulsion mechanisms, followed by an exploration of commonly studied LDSM, emphasizing their advantages. Critical properties affecting propulsion, such as surface features, morphology, and size, are presented alongside discussions on external conditions related to light sources and intensity, which are crucial for optimizing the propulsion speed. Each property is accompanied by a theoretical background and conclusions drawn up to 2018. The review further investigates recent adaptations of LDSM, uncovering underlying mechanisms and associated benefits. A brief discussion is included on potential synergistic effects between different external conditions, aiming to enhance efficiency-a relatively underexplored topic. In conclusion, the review outlines emerging applications in biomedicine and environmental monitoring/remediation resulting from recent LDSM research, highlighting the growing significance of this field. The comprehensive exploration of LDSM advancements provides valuable insights for researchers and practitioners seeking to leverage these innovative micro/nanomotors in diverse applications.

Photothermal-driven micro/nanomotors: From structural design to potential applications

Micro/nanomotors (MNMs) that accomplish autonomous movement by transforming external energy into mechanical work are attractive cargo delivery vehicles. Among various propulsion mechanisms of MNMs, photothermal propulsion has gained considerable attention because of their unique advantages, such as remote, flexible, accurate, biocompatible, short response time, etc. Moreover, besides as a propulsion source, the light has been extensively investigated as an excitation source in bioimaging, photothermal therapy (PTT), photodynamic therapy (PDT) and so on. Furthermore, the geometric topology and morphology of MNMs have a tremendous impact on improving their performance in motion behavior under NIR light propulsion, environmental suitability and functional versatility. Hence, this review article provides a comprehensive overview of structural design principles and construction strategies of photothermal-driven MNMs, and their emerging nanobiomedical applications. Finally, we further provide an outlook towards prospects and challenges during the development of photothermal-driven MNMs in the future. STATEMENT OF SIGNIFICANCE: Photothermal-driven micro/nanomotors (MNMs) that are regarded as functional cargo delivery tools have gained considerable attention because of unique advantages in propulsion mechanisms, such as remote, flexible, accurate and fully biocompatible light manipulation and extremely short light response time. The geometric topology and morphology of MNMs have a tremendous impact on improving their performance in motion behavior under NIR light propulsion, environmental suitability and functional versatility of MNMs. There are no reports about the review focusing on photothermal-driven MNMs up to now. Herein, we systematically review the latest progress of photothermal-driven MNMs including design principle, fabrication strategy of various MNMs with different structures and nanobiomedical applications. Moreover, the summary and outlook on the development prospects and challenges of photothermal-driven MNMs are proposed, hoping to provide new ideas for the future design of photothermal-driven MNMs with efficient propulsion, multiple functions and high biocompatibility.

Light-driven micro/nanomotors in biomedical applications

Nanotechnology brings hope for targeted drug delivery. However, most current drug delivery systems use passive delivery strategies with limited therapeutic efficiency. Over the past two decades, research on micro/nanomotors (MNMs) has flourished in the biomedical field. Compared with other driven methods, light-driven MNMs have the advantages of being reversible, simple to control, clean, and efficient. Under light irradiation, the MNMs can overcome several barriers in the body and show great potential in the treatment of various diseases, such as tumors, and gastrointestinal, cardiovascular and cerebrovascular diseases. Herein, the classification and mechanism of light-driven MNMs are introduced briefly. Subsequently, the applications of light-driven MNMs in overcoming physiological and pathological barriers in the past five years are highlighted. Finally, the future prospects and challenges of light-driven MNMs are discussed as well. This review will provide inspiration and direction for light-driven MNMs to overcome biological barriers in vivo and promote the clinical application of light-driven MNMs in the biomedical field.

Progress on Physical Field-Regulated Micro/Nanomotors for Cardiovascular and Cerebrovascular Disease Treatment

Cardiovascular and cerebrovascular diseases (CCVDs) are two major vasculature-related diseases that seriously affect public health worldwide, which can cause serious death and disability. Lack of targeting effect of the traditional CCVD treatment drugs may damage other tissues and organs, thus more specific methods are needed to solve this dilemma. Micro/nanomotors are new materials that can convert external energy into driving force for autonomous movement, which can not only enhance the penetration depth and retention rates, but also increase the contact areas with the lesion sites (such as thrombus and inflammation sites of blood vessels). Physical field-regulated micro/nanomotors using the physical energy sources with deep tissue penetration and controllable performance, such as magnetic field, light, and ultrasound, etc. are considered as the emerging patient-friendly and effective therapeutic tools to overcome the limitations of conventional CCVD treatments. Recent efforts have suggested that physical field-regulated micro/nanomotors on CCVD treatments could simultaneously provide efficient therapeutic effect and intelligent control. In this review, various physical field-driven micro/nanomotors are mainly introduced and their latest advances for CCVDs are highlighted. Last, the remaining challenges and future perspectives regarding the physical field-regulated micro/nanomotors for CCVD treatments are discussed and outlined.

Methylene Blue-Doped Carbonized Polymer Dots: A Potent Photooxygenation Scavenger Targeting Alzheimer's β-Amyloid

The abnormal aggregation of β-amyloid protein (Aβ) is one of the main pathological hallmarks of Alzheimer's disease (AD), and thus development of potent scavengers targeting Aβ is considered an effective strategy for AD treatment. Herein, photosensitizer-doped carbonized polymer dots (PS-CPDs) were synthesized by a one-step hydrothermal method using photosensitizer (PS) and o-phenylenediamine (oPD) as precursors, and furtherly applied to inhibit Aβ aggregation via photooxygenation. The inhibition efficiency of such PS-CPDs can be adjusted by varying the type of photosensitizer, and among them, methylene blue-doped carbonized polymer dots (MB-CPDs) showed the strongest photooxygenation inhibition capability. The results demonstrated that under 650 nm NIR light irradiation, MB-CPDs (2 μg/mL) produced reactive oxygen species (ROS) to efficiently inhibit Aβ fibrillization and disaggregate mature Aβ fibrils and increased the cultured cell viability from 50% to 83%. In vivo studies confirmed that MB-CPDs extended the lifespan of AD nematodes by 4 days. Notably, the inhibitory capability of MB-CPDs is much stronger than that of MB and previously reported carbonized polymer dots. This work indicated that potent photooxygenation carbon dots can be obtained by using a photosensitizer as one of the precursors, and the results have provided new insights into the design of potent photooxygenation carbon nanomaterials targeting Aβ in AD treatment.

Light-driven MOF-based micromotors with self-floating characteristics for water sterilization

Three-dimensional motion (especially in the Z-axis direction) of metal-organic frameworks (MOFs)-based micromotors (MOFtors) is essential but still in its infancy. Herein, we propose a simple strategy for designing light-driven MOFtors that move in the Z-axis direction and efficiently kill Staphylococcus aureus (S. aureus). The as-prepared polypyrrole nanoparticles (PPy NPs) with excellent photothermal properties are combined with ZIF-8 through a simple in situ encapsulation method, resulting in multi-wavelength photothermally-responsive MOFtors (PPy/ZIF-8). Under the irradiation of near-infrared (NIR)/ultraviolet (UV)/blue light, the MOFtors all exhibited negative phototaxis and high-speed motion behaviour with the highest speed of 2215 ± 338 μm s-1. In addition, it is proved that these MOFtors can slowly self-float up in an aqueous environment. The light irradiation will accelerate the upward movement of the MOFtors, and the time required for the MOFtors to move to the top is negatively correlated with the light intensity. Finally, efficient antibacterial performances (up to 98.89% against S. aureus) are achieved with these light-driven MOFtors owing to the boosted Zn2+ release by vigorous stirring motion and physical entrapment by the upward motion under light irradiation.

GOx-Powered Janus Platelet Nanomotors for Targeted Delivery of Thrombolytic Drugs in Treating Thrombotic Diseases

Low efficiency of targeting and delivery toward the thrombus site poses challenges to using thrombolytic drugs. Inspired by the biomimetic system of platelet membranes (PMs) and glucose oxidase (GOx) modification technologies, we develop a novel GOx-powered Janus nanomotor by asymmetrically attaching the GOx to polymeric nanomotors coated with the PMs. Then the PM-coated nanomotors were conjugated with urokinase plasminogen activators (uPAs) on their surfaces. The PM-camouflaged design conferred excellent biocompatibility to the nanomotors and improved their targeting ability to thrombus. The Janus distribution of GOx also allows the uneven decomposition of glucose in biofluids to produce a chemophoretic motion, increasing the drug delivery efficiency of nanomotors. In addition, these nanomotors are located at the lesion site due to the mutual adhesion and aggregation of platelet membranes. Furthermore, thrombolysis effects of nanomotors are enhanced in static and dynamic thrombus as well as in mouse models. It is believed that the novel PM-coated enzyme-powered nanomotors represent a great value for thrombolysis treatment.

Photooxidative inhibition and decomposition of β-amyloid in Alzheimer's by nano-assemblies of transferrin and indocyanine green

Photoinduced modulation of Aβ₄₂ aggregation has emerged as a therapeutic option for treating Alzheimer's disease (AD) due to its high spatiotemporal controllability, noninvasive nature, and low systemic toxicity. However, existing photo-oxidants have the poor affinity for Aβ₄₂, low depolymerization efficiency, and difficulty in crossing the blood-brain barrier (BBB), hindering their application in the treatment of AD. Here, through hydrophobic interactions and hydrogen bonding, we integrated the near-infrared (NIR) photosensitizer indocyanine green with transferrin (denoted as TF-ICG), a protein with a high affinity for Aβ₄₂, and demonstrated its anti-amyloid activity in vitro. TF-ICG was shown to bind to Aβ₄₂ residues via hydrophobic interaction, impeding π-π stacking of Aβ₄₂ peptide monomers and disassembling mature Aβ₄₂ protofibrils in a concentration-dependent manner. More importantly, under NIR (808 nm, 0.6w/cm²) irradiation, TF-ICG completely inhibited the fibrillation process of Aβ₄₂ to generate amorphous aggregates, with an inhibition rate of 96 % at only 65 nM. Meanwhile, TF-ICG could photo-oxidize rigid Aβ₄₂ aggregates and break them down into small amorphous structures. Tyrosine fluorescence assay further demonstrated the intrinsic affinity and targeting of TF-ICG to Aβ₄₂ fibrils. In vitro studies validated the anti-amyloid activity of TF-ICG, which provided a theoretical basis for further in vivo application as a BBB-penetrating nanotherapeutic platform.

A Biomolecular Toolbox for Precision Nanomotors

The application of nanomotors for cancer diagnosis and therapy is a new and exciting area of research, which when combined with precision nanomedicine, promises to solve many of the issues encountered by previous development of passive nanoparticles. The goal of this article is to introduce nanomotor and nanomedicine researchers to the deep pool of knowledge available regarding cancer cell biology and biochemistry, as well as provide a greater appreciation of the complexity of cell membrane compositions, extracellular surfaces, and their functional consequences. A short description of the nanomotor state-of-art for cancer therapy and diagnosis is first provided, as well as recommendations for future directions of the field. Then, a biomolecular targeting toolbox has been collated for researchers looking to apply their nanomaterial of choice to a biological setting, as well as providing a glimpse into currently available clinical therapies and technologies. This toolbox contains an overview of different classes of targeting molecules available for high affinity and specific targeting and cell surface targets to aid researchers in the selection of a clinical disease model and targeting methodology. It is hoped that this review will provide biological context, inspiration, and direction to future nanomotor and nanomedicine research.

On Nanomachines and Their Future Perspectives in Biomedicine

Nano/micromotors are a class of active matter that can self-propel converting different types of input energy into kinetic energy. The huge efforts that are made in this field over the last years result in remarkable advances. Specifically, a high number of publications have dealt with biomedical applications that these motors may offer. From the first attempts in 2D cell cultures, the research has evolved to tissue and in vivo experimentation, where motors show promising results. In this Perspective, an overview over the evolution of motors with focus on bio-relevant environments is provided. Then, a discussion on the advances and challenges is presented, and eventually some remarks and perspectives of the field are outlined.

NIR-II Light Powered Asymmetric Hydrogel Nanomotors for Enhanced Immunochemotherapy

Nanomotors are appealing drug carriers, and the strength of the propelling force is important for their motion capability. Though high motion efficiency has been achieved with 808 nm light driven Janus-structured noble metal nanomotors, the NIR-I light penetration depth and material biocompatibility limit their broad application. Herein, we develop a 1064 nm NIR-II light driven asymmetric hydrogel nanomotor (AHNM) with high motion capability and load it with doxorubicin for enhanced immunochemotherapy. Magnetic field assisted photopolymerization generates an asymmetric distribution of Fe₃ O₄ @Cu₉ S₈ nanoparticles in the AHNM, producing self-thermophoresis as driving force under NIR-II irradiation. The AHNM is also functionalized with dopamine for the capture and retention of tumor-associated antigens to boost immune activation. The as-obtained NIR-II light driven AHNM has a high tumor tissue penetration capability and enhances immunochemotherapy, providing a promising strategy for cancer therapy.

NIR light-propelled bullet-shaped carbon hollow nanomotors with controllable shell thickness for the enhanced dye removal

Materials with asymmetric nanostructures have attracted tremendous research attention due to their unique structural characteristics, excellent physicochemical properties, and promising prospects. However, it is still difficult to design and fabricate bullet-shaped nanostructure due to its structural complexity. Herein, for the first time, we successfully constructed NIR light-propelled bullet-shaped hollow carbon nanomotors (BHCNs) with an open mouth on the bottom of nano-bullet for the enhanced dye removal, by employing bullet-shaped silica nanoparticles (B-SiO₂ NPs) as a hard template. BHCNs were formed by the growth of polydopamine (PDA) layer on the heterogeneous surface of B-SiO₂ NPs, followed by the carbonization of PDA and subsequent selective etching of SiO₂. The shell thickness of BHCNs was able to be facilely controlled from ≈ 14 to 30 nm by tuning the added amount of dopamine. The combination of streamlined bullet-shaped nanostructure with good photothermal conversion efficiency of carbon materials facilitated the generation of asymmetric thermal gradient field around itself, thus driving the motion of BHCNs by self-thermophoresis. Noteworthily, the diffusion coefficient (De) and velocity of BCHNs with shell thickness of 15 nm (BHCNs-15) reached to 43.8 μm⋅cm^-2 and 11.4 μm⋅s^-1, respectively, under the illumination of 808 nm NIR laser with the power density of 1.5 W⋅cm^-2. The NIR laser propulsion caused BCHNs-15 to enhance the removal efficiency (53.4% vs. 25.4%) of methylene blue (MB) as a typical dye because the faster velocity could produce the higher micromixing role between carbon adsorbent and MB. Such a smart design of the streamlined nanomotors may provide a promising potential in environmental treatment, biomedical and biosensing applications.

Dual-Mode-Driven Micromotor Based on Foam-like Carbon Nitride and Fe3O4 with Improved Manipulation and Photocatalytic Performance

Micro/nanomotors have emerged as a vibrant research topic in biomedical and environmental fields due to their attractive self-propulsion as well as small-scale functionalities. However, single actuated micro/nanomotors are not adaptive in facing intricate natural and industrial environments. Herein, we propose a new dual-mode-driven micromotor based on foam-like carbon nitride (f-C₃N₄) with precipitated Fe₃O₄ nanoparticles, namely, Fe₃O₄/f-C₃N₄, powered by chemical/magnetic stimuli for rapid reduction of organic pollutants. The Fe₃O₄/f-C₃N₄ motor composed of a three-dimensional (3D) porous "foam-like" structure and precipitated Fe₃O₄ nanoparticles (ca. 50 nm) not only exhibits efficient photocatalytic performance under visible light but also shows versatile and programmable motion behavior under the control of external magnetic fields. The aggregation of the micromotor under an external rotating magnetic field further enhances the catalytic activity by the increased local catalyst concentration. Furthermore, the magnetic property endows the micromotor with easy recyclability. This study provides a novel dual-mode-driven micromotor for antibiotics removal with magnetic field and light-enhanced performance in industrial wastewater treatment at a low cost.

Enzyme-Free Liposome Active Motion via Asymmetrical Lipid Efflux

As a class of biocompatible, water-dispersed colloids, liposomes have found widespread applications ranging from food to drug delivery. Adding mobility to these colloids, i.e., liposome micromotors, represents an attractive approach to next-generation liposome carriers with enhanced functionality and effectiveness. Currently, it remains unclear as to the scope of material features useful for building liposome micromotors or how they may differ functionally from their inorganic/polymer counterparts. In this work, we demonstrate liposome active motion taking advantage of mainly a pair of intrinsic material properties associated with these assemblies: lipid phase separation and extraction. We show that global phase separation of ternary lipid systems (such as DPPC/DOPC/cholesterol) within individual liposomes yields stable Janus particles with two distinctive liquid domains. While these anisotropic liposomes undergo pure Brownian diffusion in water, similar to their homogeneous analogues, adding extracting agents, cyclodextrins, to the system triggers asymmetrical cholesterol efflux about the liposomes, setting the latter into active motion. We present detailed analyses of liposome movement and cholesterol extraction kinetics to establish their correlation. We explore various experimental parameters as well as mechanistic details to account for such motion. Our results highlight the rich possibility to hierarchically design lipid-based artificial motors, from individual lipids, to their organization, surface chemistry, and interfacial mechanics.

Nontoxic silicene photothermal agents with high near-infrared absorption for disassembly of Alzheimer's amyloid‑β fibrils

The disassembly and eliminating the amyloid-β (Aβ) aggregates has become an effective way to treat Alzheimer's disease (AD). Herein, for the first time, the near-infrared (NIR) activated silicene nanosheets (SNSs) have been identified as an effective nontoxic photothermal conversion agent for irreversibly disassembly of the Aβ_33-42 aggregates. The SNSs synthesized by a combination of mild oxidation method and liquid exfoliation method possess good biocompatibility and biodegradability, and high near-infrared photothermal conversion capabilities. Under NIR light, the SNSs could disassemble the large and dense Aβ_33-42 mature fibrils into short fibrils and even form thin films, leading to the degradation rate of 96.47%. The circular dichroism spectrum, fluorescent spectra, and nanostructure were analyzed to monitor the photothermal degradation of mature Aβ_33-42 fibrils for elaborating the mechanism beneath. This study might provide a clue for developing potential therapeutic strategy for AD and related neurodegenerative diseases.

Composite of gold nanoclusters and basified human serum albumin significantly boosts the inhibition of Alzheimer's β-amyloid by photo-oxygenation

Photo-oxygenation has become an effective way to inhibit Alzheimer's β-amyloid protein (Aβ) fibrillogenesis, which involves oxidative modification of Aβ by photo-oxidants. However, limitations of the current photo-oxidants, such as low biocompatibility and low affinity for Aβ, hinder the progression of the photo-oxygenation strategy. Herein, using human serum albumins (HSA) with binding affinity for Aβ as a platform, we have fabricated HSA-stabilized gold nanoclusters (AuNCs@HSA) and further modified the AuNCs@HSA with ethylenediamine to create basified HSA (HSA-B)-stabilized AuNCs. The basified composite, AuNCs@HSA-B, showed significantly higher potency on the inhibition of β-amyloid formation and capability of reactive oxidative species generation than AuNCs@HSA. In addition to the inhibition effect, under near-infrared (NIR) laser irradiation, AuNCs@HSA-B generated singlet oxygen to oxygenate Aβ monomers, distinctly alleviating Aβ-mediated neurotoxicity at a low concentration. In vivo studies demonstrated that NIR-activated AuNCs@HSA-B promoted the lifespan extension of transgenic C. elegans strain CL2006 by decreasing the Aβ burden. This well-designed AuNCs@HSA-B integrates inhibition, Aβ targeting, and photo-oxygenation, providing new insights into the development of protein-based photo-oxidant against Alzheimer's β-amyloid. STATEMENT OF SIGNIFICANCE: Alzheimer's disease (AD) has been threatening human health for more than 100 years. Recently, researchers have focused on inhibiting β-amyloid protein (Aβ) aggregation by exploring photo-excited biomaterials, which enable modulation of Aβ fibrillization with high spatiotemporal controllability. The present work demonstrates the fabrication of basified human serum albumins (HSA-B)-stabilized gold nanoclusters (AuNCs@HSA-B), and shows the potential of this near-infrared (NIR) laser-activated AuNCs@HSA-B as a photo-oxidant against Aβ aggregation by photo-oxygenation. Our work should open a new horizon in the design of protein-based photo-oxidant for treating AD 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.

Magnetic Nanomotors in Emulsions for Locomotion of Microdroplets

The locomotion of droplets in emulsions is of practical significance for fields related to medicine and chemical engineering, which can be done with a magnetic field to move droplets containing magnetic materials. Here, we demonstrate a new method of droplet locomotion in the oil-in-water emulsion with the help of a nonuniform magnetic field in the case where magnetic nanoparticles (MNPs) are dispersed in the continuous phase of the emulsion. The paper analyses the motion of the droplets in a liquid film and in a capillary for various diameters of droplets, their number density, and viscosity of the continuous phase of the emulsion. It is established that the mechanism of droplet locomotion in the emulsion largely depends on the wettability of MNPs. Hydrophobic nanoparticles are adsorbed on the droplet surfaces, forming the agglomerates of MNPs with the droplets. Such agglomerates move at much higher velocities than passive droplets. Hydrophilic nanoparticles are not adsorbed at the surfaces of the droplets but form mobile magnetic clusters dispersed in the continuous phase of the emulsion. Mobile magnetic clusters set the surrounding liquid and droplets in motion. The results obtained in this paper can be used in drug delivery.

Powering bioanalytical applications in biomedicine with light-responsive Janus micro-/nanomotors

Possessing both unique asymmetric structures and remote-controlled active movement, light-responsive Janus micro-/nanomotors offer the possibility of breaking through the limitations of traditional biomedicine, and have fascinated and inspired researchers. Despite many obstacles toward the clinical application, impressive progress of light-responsive Janus micro-/nanomotors for bioanalytical applications has been made over the past decades. In this review, we first briefly introduced several main light-driven Janus micro-/nanomotors, then focused on their typical bioanalytical applications such as biosensing, bioimaging, and theranostic. In the end, we summarized the remaining challenges of light-responsive Janus micro-/nanomotors in the practical application and also proposed potential solutions in the future.

Near-infrared Irradiation Controlled Thermo-Switchable Polymeric Photosensitizer against β-Amyloid Fibrillation

Photothermal therapy (PTT) as an emerging paradigm toward degradation of amyloid-β (Aβ) aggregations has become an effective way of treating Alzheimer’s disease (AD). A promising PTT therapeutic option requires control...

Coassembled Chitosan-Hyaluronic Acid Nanoparticles as a Theranostic Agent Targeting Alzheimer's β-Amyloid

β-Amyloid (Aβ) fibrillogenesis is closely associated with the pathogenesis of Alzheimer's disease (AD), so detection and inhibition of Aβ aggregation are of significance for the theranostics of AD. In this work, the coassembled nanoparticles of chitosan and hyaluronic acid cross-linked with glutaraldehyde (CHG NPs) were found to work as a theranostic agent for imaging/probing and inhibition of Aβ fibrillization both in vitro and in vivo. The biomass-based CHG NPs of high stability exhibited a wide range of excitation/emission wavelengths and showed binding affinity toward Aβ aggregates, especially for soluble Aβ oligomers. CHG NPs displayed weak emission in the monodispersed state, while they remarkably emitted increased red fluorescence upon interacting with Aβ oligomers and fibrils, showing high sensitivity with a detection limit of 0.1 nM. By comparing the different fluorescence responses of CHG NPs and Thioflavin T to Aβ aggregation, the Aβ oligomerization rate during nucleation can be determined. Moreover, the fluorescence recognition behavior of CHG NPs was selective. CHG NPs specifically bind to negatively charged amyloid aggregates but not to positively charged amyloids and negatively charged soluble proteins. Such enhancement in fluorescence emission is attributed to the clustering-triggered emission effect of CHG NPs after interaction with Aβ aggregates via various electronic conjugations and hydrogen bonding, electrostatic, and hydrophobic interactions. Besides fluorescent imaging/probing, CHG NPs over 360 μg/mL could almost completely inhibit the formation of Aβ fibrils, exhibiting the capability of regulating Aβ aggregation. In-vivo assays with Caenorhabditis elegans CL2006 demonstrated the potency of CHG NPs as an effective theranostic nanoagent for imaging Aβ plaques and inhibiting Aβ deposition. The findings proved the potential of CHG NPs for development as a potent agent for the diagnosis and treatment of AD.

General Thermodynamic-Controlled Coating Method to Prepare Janus Mesoporous Nanomotors for Improving Tumor Penetration

Artificial nanomotors are undergoing significant developments in several biomedical applications. However, current experimental strategies for producing nanomotors still have inherent drawbacks such as the requirement for expensive equipment, strict controlling of experimental conditions, and strenuous processes with several complex procedures. In this study, we describe for the first time a facile single-step thermodynamic-controlled coating method to prepare Janus mesoporous organosilica nanomotors. By controlling the total free energy of organosilica oligomers (G) from a low development level to a high level in the reaction system, the nonspontaneous nucleation on the platinum (Pt) nanosurface and the spontaneous nucleation in a solvent can be controlled, respectively. More importantly, we reveal that the molecular arrangement and contact angle of deposited organosilica on Pt cores vary with the total free energy of organosilica oligomers (G). Different values of θ would change the trend of detachment from Pt for organosilica nucleated cores and carry out diverse coating modes. These are indicated by the morphology evolution of platinum/organosilica hybrids, from naked platinum nanoparticles, evenly distributed organosilica shell/core, nonconcentric to typical Janus nanomotor. The prepared Janus mesoporous nanomotor (JMN) showed typical mesopore structures and active propelling behaviors under H₂O₂ stimulation. In addition, the JMN modified with hyaluronic acid exhibited excellent biocompatibility and improved tumor penetration under H₂O₂ stimulation. The successful construction of other nanomotor frameworks based on a gold-templated core proves the perfect applicability of the thermodynamic-coating method for the production of nanomotors. In conclusion, this work establishes a manufacturing methodology for nanomotors and drives nanomotors for promising biomedical applications.

Multifunctional micro/nanomotors as an emerging platform for smart healthcare applications

Self-propelling micro- and nano-motors (MNMs) are emerging as a multifunctional platform for smart healthcare applications such as biosensing, bioimaging, and targeted drug delivery with high tissue penetration, stirring effect, and rapid drug transport. MNMs can be propelled and/or guided by chemical substances or external stimuli including ultrasound, magnetic field, and light. In addition, enzymatically powered MNMs and biohybrid micromotors have been developed using the biological components in the body. In this review, we describe emerging MNMs focusing on their smart propulsion systems, and diagnostic and therapeutic applications. Finally, we highlight several MNMs for in vivo applications and discuss the future perspectives of MNMs on their current limitations and possibilities toward further clinical applications.

A Practical Guide to Analyzing and Reporting the Movement of Nanoscale Swimmers

The recent invention of nanoswimmers-synthetic, powered objects with characteristic lengths in the range of 10-500 nm-has sparked widespread interest among scientists and the general public. As more researchers from different backgrounds enter the field, the study of nanoswimmers offers new opportunities but also significant experimental and theoretical challenges. In particular, the accurate characterization of nanoswimmers is often hindered by strong Brownian motion, convective effects, and the lack of a clear way to visualize them. When coupled with improper experimental designs and imprecise practices in data analysis, these issues can translate to results and conclusions that are inconsistent and poorly reproducible. This Perspective follows the course of a typical nanoswimmer investigation from synthesis through to applications and offers suggestions for best practices in reporting experimental details, recording videos, plotting trajectories, calculating and analyzing mobility, eliminating drift, and performing control experiments, in order to improve the reliability of the reported results.

Precise Control of Customized Macrophage Cell Robot for Targeted Therapy of Solid Tumors with Minimal Invasion

Injecting micro/nanorobots into the body to kill tumors is one of the ultimate ambitions for medical nanotechnology. However, injecting current micro/nanorobots based on 3D-printed biocompatible materials directly into blood vessels for targeted therapy is often difficult, and mistakes in targeting can cause serious side effects, such as blood clots, oxidative stress, or inflammation. The natural affinity of macrophages to tumors, and their natural phagocytosis and ability to invade tumors, make them outstanding drug delivery vehicles for targeted tumor therapy. Hence, a magnetically controlled cell robot (MCR) based on a macrophage drug carrier is proposed. Here, living macrophages are converted into MCRs through endocytosis of specially-designed magnetic nanoparticles loaded with doxorubicin and indocyanine green. Following this, the MCRs can be transported to tumors through the blood vessels using external magnetic fields, and penetrate the blood vessels into the interior of the tumor due to their deformability. With the MCR's cascaded drug release, targeted killing of tumors in mice is demonstrated, with minimal effects on the normal surrounding tissue. The ability to impart precise drug doses onto natural cells, such as macrophages, and load various functional components into the MCRs, offers an efficient method for precise targeted therapy.

Biosafety, Functionalities, and Applications of Biomedical Micro/nanomotors

Due to their unique ability to actively move, micro/nanomotors offer the possibility of breaking through the limitations of traditional passive drug delivery systems for the treatment of many diseases, and have attracted the increasing attention of researchers. However, at present, the realization of many advantages of micro/nanomotors in disease treatment in vivo is still in its infancy, because of the complexity and particularity of diseases in different parts of human body. In this Minireview, we first focus on the biosafety and functionality of micro/nanomotors as a biomedical treatment system. Then, we address the treatment difficulties of various diseases in vivo (such as ophthalmic disease, orthopedic disease, gastrointestinal disease, cardiovascular disease, and cancer), and then review the research progress of biomedical micro/nanomotors in the past 20 years, Finally, we propose the challenges in this field and possible future development directions.

Janus Nanoparticles: From Fabrication to (Bio)Applications

Janus nanoparticles (JNPs) refer to the integration of two or more chemically discrepant composites into one structure system. Studies into JNPs have been of significant interest due to their interesting characteristics stemming from their asymmetric structures, which can integrate different functional properties and perform more synergetic functions simultaneously. Herein, we present recent progress of Janus particles, comprehensively detailing fabrication strategies and applications. First, the classification of JNPs is divided into three blocks, consisting of polymeric composites, inorganic composites, and hybrid polymeric/inorganic JNPs composites. Then, the fabrication strategies are alternately summarized, examining self-assembly strategy, phase separation strategy, seed-mediated polymerization, microfluidic preparation strategy, nucleation growth methods, and masking methods. Finally, various intriguing applications of JNPs are presented, including solid surfactants agents, micro/nanomotors, and biomedical applications such as biosensing, controlled drug delivery, bioimaging, cancer therapy, and combined theranostics. Furthermore, challenges and future works in this field are provided.

Polypyrrole-Based Nanorobots Powered by Light and Glucose for Pollutant Degradation in Water

Novel photoactive and enzymatically active nanomotors were developed for efficient organic pollutant degradation. The developed preparation route is simple and scalable. Light-absorbing polypyrrole nanoparticles were equipped with a bi-enzyme [glucose oxidase/catalase (GOx/Cat)] system enabling the simultaneous utilization of light and glucose as energy sources for jet-induced nanoparticle movement and active radical production. The GOx utilizes glucose to produce hydrogen peroxide, which is subsequently degraded by Cat, resulting in the generation of active radicals and/or oxygen bubbles that propel the particles. Uneven grafting of GOx/Cat molecules on the nanoparticle surface ensures inhomogeneity of peroxide creation/degradation, providing the nanomotor random propelling. The nanomotors were tested for their ability to degrade chlorophenol, under various experimental conditions, that is, with and without simulated sunlight illumination or glucose addition. In all cases, degradation was accelerated by the presence of the self-propelled nanoparticles or light illumination. Light-induced heating also positively affects enzymatic activity, further accelerating nanomotor diffusion and pollutant degradation. In fact, the chemical and photoactivities of the nanoparticles led to more than 95% removal of chlorophenol in 1 h, without any external stirring. Finally, the quality of the purified water and the extent of pollutant removal were checked using an eco-toxicological assay, with demonstrated significant synergy between glucose pumping and sunlight illumination.

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.

Gastric Acid Powered Nanomotors Release Antibiotics for In Vivo Treatment of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection has ≈75% probability of causing gastric cancer, so it is considered to be the strongest single risk factor for gastric malignancies. However, the harsh gastric acid environment has created obstacles to medical treatment. This work reports a nanomotor with a bottle-shaped container that can be loaded with small molecules of clarithromycin, nano calcium peroxide (CaO₂ ), and Pt nanoparticles (Pt NPs) by ultrasound. Nanomotors can quickly consume gastric acid through the chemical reaction of CaO₂ to temporarily neutralize gastric acid. The product hydrogen peroxide (H₂ O₂ ) is catalytically decomposed into a large amount of oxygen (O₂ ) by Pt NPs. The local concentration gradient of O₂ bubbles causes it to be expelled from the nanobottles through a narrow opening, and then push the nanobottles forward to provide maximum release and prodrug efficacy. Experiments in animal models show that 15 mg nanomotors can safely and quickly neutralize gastric acid in the stomach and simultaneously release prodrugs to achieve good therapeutic effects without causing acute toxicity. H. pylori burden in mice was 2.6 orders of magnitude lower than that in the control group. The stomach returns to normal pH within 1 d after administration.

A Journey of Nanomotors for Targeted Cancer Therapy: Principles, Challenges, and a Critical Review of the State-of-the-Art

A nanomotor is a miniaturized device that converts energy stored in the environment into mechanical motion. The last two decades have witnessed a surge of research interests in the biomedical applications of nanomotors, but little clinical translation. To accelerate this process, targeted cancer therapy is used as an example to describe a "survive, locate, operate, and terminate" (SLOT) mission of a nanomotor, where it must 1) survive in the unfriendly in vivo environment, 2) locate its target as well as be located by human operators, 3) carry out specific operations, and 4) terminate after the mission is completed. Along this journey, the challenges presented to a nanomotor, including to power, navigate, steer, target, release, control, image, and communicate are discussed, and how state-of-the-art nanomotors meet or fall short of these requirements is critically reviewed. These discussions are then condensed into a table for easy reference. In particular, it is argued that chemically powered nanomotors are intrinsically ill-positioned for targeted cancer therapy, while nanomotors powered by magnetic fields or ultrasound show more promises. Following this argument, a tentative nanomotor design is then presented in the end to conform to the SLOT guideline, and to inspire practical, functional nanorobots that are yet to come.

Self-Propelled Micro/Nanomotors for Tumor Targeting Delivery and Therapy

Cancer is still one of the most serious diseases with threats to health and life. Although some advances have been made in targeting delivery of antitumor drugs over the past number of years, there are still many problems needing to be solved, such as poor efficacy and high systemic toxicity. Micro/nanomotors capable of self-propulsion in fluid provide promising platforms for improving the efficiency of tumor delivery. Herein, the recent progress in micro/nanomotors for tumor targeting delivery and therapy is reviewed, with special focus on the contributions of micro/nanomotors to the different stages of tumor targeting delivery as well as the combination therapy by micro/nanomotors. The present limitations and future directions are also put forward for further development.

Fast green FCF inhibits Aβ fibrillogenesis, disintegrates mature fibrils, reduces the cytotoxicity, and attenuates Aβ-induced cognitive impairment in mice

Fast green FCF (FGF) is often used in foods, pharmaceuticals, and cosmetics. However, little is known about the interactions of FGF with amyloid-β protein (Aβ) associated with Alzheimer's disease. In this study, the inhibitory effects of FGF on Aβ fibrillogenesis, the disruption of preformed Aβ fibrils, the reduction of Aβ-induced cytotoxicity, and the attenuation of Aβ-induced learning and memory impairments in mice were investigated. FGF significantly inhibited Aβ fibrillogenesis and disintegrated the mature fibrils as evidenced by thioflavin T fluorescence and atomic force microscopy studies. Co-incubation of Aβ with FGF greatly reduced Aβ-induced cytotoxicity in vitro. Moreover, FGF showed a protective effect against cognitive impairment in Aβ-treated mice. Molecular dynamics simulations further showed that FGF could synergistically interact with the Aβ17-42 pentamer via electrostatic interactions, hydrogen bonds and π-π interactions, which reduced the β-sheet content, and disordered random coils and bend structures of the Aβ17-42 pentamer. This study offers a comprehensive understanding of the inhibitory effects of FGF against Aβ neurotoxicity, which is critical for the search of effective food additives that can combat amyloid-associated disease.

Target-driven supramolecular self-assembly for selective amyloid-β photooxygenation against Alzheimer's disease

Photo-oxygenation of β-amyloid (Aβ) has been considered an efficient way to inhibit Aβ aggregation in Alzheimer's disease (AD). However, current photosensitizers cannot simultaneously achieve enhanced blood-brain barrier (BBB) permeability and selective photooxygenation of Aβ, leading to poor therapeutic efficacy, severe off-target toxicity, and substandard bioavailability. Herein, an Aβ target-driven supramolecular self-assembly (PKNPs) with enhanced BBB penetrability and switchable photoactivity is designed and demonstrated to be effective in preventing Aβ aggregation in vivo. PKNPs are prepared by the self-assembly of the Aβ-targeting peptide KLVFF and an FDA-approved porphyrin derivative (5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin). Due to the photothermal effect of PKNPs, the BBB permeability of PKNPs under irradiation is 8.5-fold higher than that of porphyrin alone. Moreover, upon selective interaction with Aβ, PKNPs undergo morphological change from the spherical to the amorphous form, resulting in a smart transformation from photothermal activity to photodynamic activity. Consequently, the disassembled PKNPs can selectively oxygenate Aβ without affecting off-target proteins (insulin, bovine serum albumin, and human serum albumin). The well-designed PKNPs exhibit not only improved BBB permeability but also highly selective Aβ photooxygenation. Furthermore, in vivo experiments demonstrate that PKNPs can alleviate Aβ-induced neurotoxicity and prolong the life span of the commonly used AD transgenic Caenorhabditis elegans CL2006. Our work may open a new path for using supramolecular self-assemblies as switchable phototheranostics for the selective and effective prevention of Aβ aggregation and related neurotoxicity in AD.

Redox-Responsive Nanobiomaterials-Based Therapeutics for Neurodegenerative Diseases

Redox regulation has recently been proposed as a critical intracellular mechanism affecting cell survival, proliferation, and differentiation. Redox homeostasis has also been implicated in a variety of degenerative neurological disorders such as Parkinson's and Alzheimer's disease. In fact, it is hypothesized that markers of oxidative stress precede pathologic lesions in Alzheimer's disease and other neurodegenerative diseases. Several therapeutic approaches have been suggested so far to improve the endogenous defense against oxidative stress and its harmful effects. Among such approaches, the use of artificial antioxidant systems has gained increased popularity as an effective strategy. Nanoscale drug delivery systems loaded with enzymes, bioinspired catalytic nanoparticles and other nanomaterials have emerged as promising candidates. The development of degradable hydrogels scaffolds with antioxidant effects could also enable scientists to positively influence cell fate. This current review summarizes nanobiomaterial-based approaches for redox regulation and their potential applications as central nervous system neurodegenerative disease treatments.

Light-driven nanomotors and micromotors: envisioning new analytical possibilities for bio-sensing

The aim of this conceptual review is to cover recent developments of light-propelled micromotors for analytical (bio)-sensing. Challenges of self-propelled light-driven micromotors in complex (biological) media and potential solutions from material aspects and propulsion mechanism to achieve final analytical detection for in vivo and in vitro applications will be comprehensively covered. Graphical abstract.

Molecular Mediation of Prion-like α-Synuclein Fibrillation from Toxic PFFs to Nontoxic Species

Braak's theory described Parkinson's disease (PD) progression as prion-like α-synuclein (αSyn) spreading, which fundamentally subverts the understanding of pathogenesis. The pathological αSyn spreading pathway includes uptake, propagation, and release. However, the previous disease models were limitedly focusing on amyloid propagation/aggregation, which significantly impedes the mechanism exploration in spreading pathways and related therapeutic development. The spreading model can be achieved using recombinant αSyn preformed fibrils (PFFs), which seeds endogenous αSyn monomer to aggregation and causes substantial pathology and neurotoxicity. Here, we determined that dihydromyricetin (DHM), a natural flavonoid extracted from Ampelopsis grossedentata, can promote the fibrillization of prion-like PFF and induce propagation to form a distinct strain. Furthermore, administration of DHM significantly reduced prion-like PFF-induced propagation and neurotoxicity. The discovery of inducing infectious and neurotoxic PFF to a nontoxic strain resulting in neuron protection via promoting the fibrillization of PFF rather than inhibiting advances the understanding of the prion-like spreading mechanism and helps in developing treatments against PD and related α-synucleinopathies.

Multiwavelength Phototactic Micromotor with Controllable Swarming Motion for "Chemistry-on-the-Fly"

Artificial nano/micromotors that represent the next-generation automotive microdevices hold considerable promise in various potential applications. However, it is a great challenge to design light-powered micro/nanomotors with effective propulsion that can fulfill diverse tasks. Herein, a multilight-responsive micromotor is fabricated by in situ precipitation of photothermal Fe₃O₄ nanoparticles (NPs) onto different microparticles. The composites exhibit phototactic swarming movement by irradiation at 320-550 nm, which can be reversibly and remotely manipulated by irradiation position, "on/off" switch, and light intensity. The micromotor made of Fe₃O₄@poly(glycidyl methacrylate)/polystyrene (Fe₃O₄@PGS) core-shell particles presents a propulsion speed as high as 270 μm/s under ultraviolet (UV) irradiation. Using an array of experimental methods and numerical simulations, thermal convection mechanism is proposed for the propulsion. Namely, under light irradiation, the photogenerated heat on Fe₃O₄ NPs decreases the density of the irradiated spot, leading to the swarming motion of the composite particles propelled by a "hydrodynamic drag" toward the light spot. Then, Fe₃O₄@PGS is exploited as a platform for performing "chemistry-on-the-fly" using both the catalytic efficiency of Fe₃O₄ NPs and an immobilized enzyme (lipase). It is found that the propulsion increases the catalytic efficiency of Fe₃O₄ NPs for rhodamine B degradation by over 10 times under sunlight. Moreover, it is proved to accelerate the enzymatic reactions of lipase on Fe₃O₄@PGS in both aqueous and organic systems by more than 50%. Such a multiwavelength phototactic swimmer paves the way to the design of advanced micromotors for various applications, such as drug delivery, microsurgery, and sensing.

Innovative Therapies and Nanomedicine Applications for the Treatment of Alzheimer's Disease: A State-of-the-Art (2017-2020)

The field of nanomedicine is constantly expanding. Since the first work dated in 1999, almost 28 thousand articles have been published, and more and more are published every year: just think that only in the last five years 20,855 have come out (source PUBMED) including original research and reviews. The goal of this review is to present the current knowledge about nanomedicine in Alzheimer’s disease, a widespread neurodegenerative disorder in the over 60 population that deeply affects memory and cognition. Thus, after a brief introduction on the pathology and on the state-of-the-art research for NPs passing the BBB, special attention is placed to new targets that can enter the interest of nanoparticle designers and to new promising therapies. The authors performed a literature review limited to the last three years (2017–2020) of available studies with the intention to present only novel formulations or approaches where at least in vitro studies have been performed. This choice was made because, while limiting the sector to nanotechnology applied to Alzheimer, an organic census of all the relevant news is difficult to obtain.