Stepwise Coordination-Driven Metal-Phenolic Nanoparticle as a Neuroprotection Enhancer for Alzheimer's Disease Therapy

Fe-Doped Carbon Dots Alleviated Rheumatoid Arthritis by Inhibiting Neutrophil NETosis and Autophagy

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disorder primarily affecting joints, characterized by high incidence rates and significantly impairing patients' quality of life. Neutrophils play a pivotal role in RA pathogenesis, making therapeutic interventions targeting neutrophil-mediated inflammatory cascades a promising strategy for RA treatment.

METHODS

Inspired by traditional Tibetan medicinal formulations, which typically combine metallic minerals and organic components, this study developed iron-doped carbon dots (MM-CDs) via a facile one-pot synthesis approach using magnetite (Cishi) and medicated leaven (Shenqu). The therapeutic efficacy of MM-CDs was subsequently evaluated in a mouse model of RA. The results indicated that MM-CDs effectively alleviated RA by disrupting neutrophil-induced inflammatory cascades. Specifically, MM-CDs inhibited NETosis, significantly downregulated myeloperoxidase (MPO), citrullinated histone H3 (Cit-H3), and peptidyl arginine deiminase 4 (PAD-4) in joint tissues (P < 0.05). Furthermore, MM-CDs modulated autophagy pathways, suppressing LC3B and Beclin-1 expression, thereby reducing neutrophil survival. Additionally, MM-CDs promoted apoptosis in neutrophils, evidenced by increased cleaved caspase-3/PARP expression and decreased Bcl-2 levels in LPS-stimulated neutrophils.

CONCLUSION

This study demonstrates that MM-CDs represent a novel and effective therapeutic strategy for RA. Importantly, the treatment exhibited no liver or kidney toxicity in the RA mouse model, highlighting its potential for safe clinical translation.

Chryxanthone A, an extracted substance from endophytic fungal Aspergillus versicolor, produces anti-oxidant neuroprotection possibly via the action on mTOR/CREB axis

BACKGROUND

Neurons are susceptible to oxidative stress due to the elevated reactive oxygen species (ROS) production and the limited antioxidant defense mechanisms. Therefore, it is possible to treat oxidative stress-related neurological disorders via the inhibition of oxidative stress. Chryxanthone A is an extracted substance derived from the endophytic fungal Aspergillus versicolor, with an atypical dihydropyran ring. However, it is unknown whether and how chryxanthone A could produce anti-oxidant protection.

PURPOSES

The activity and mechanisms underlying the anti-oxidant protection of chryxanthone A were explored in the study.

STUDY DESIGN AND METHODS

HT22 neuronal cells were used to evaluate the anti-oxidant protection of chryxanthone A. Comprehensive bioinformatic methods, including RNA-seq analysis, transcription factor prediction, CMap prediction and molecular docking analysis, were utilized to explore the molecular mechanisms how chryxanthone A prevented oxidative stress, which was confirmed by Western blotting analysis.

RESULTS

Chryxanthone A concentration-dependently prevented H2O2-induced cell death and increase in intracellular ROS in HT22 cells. Results from RNA-seq and bioinformatic analysis indicated that chryxanthone A might act on mTOR/CREB axis, possibly via binding to the Val2227 site within ATP binding pocket of mTOR. The action of chryxanthone A on H2O2-induced alteration of mTOR/CREB axis were further confirmed in HT22 cells.

CONCLUSION

These results suggested that chryxanthone A produced anti-oxidant protection via the action on mTOR/CREB axis, providing a support that chryxanthone A might be developed as a novel drug candidate for the treatment of oxidative stress-related disorders.

Nanoscale drug formulations for the treatment of Alzheimer's disease progression

Alzheimer's disease (AD) is a devastating neurodegenerative disorder with no effective disease-modifying treatments. The blood-brain barrier hinders drug delivery to the brain, limiting therapeutic efficacy. Nanoparticle-based systems have emerged as promising tools to overcome these challenges. This review highlights recent advances in nanoparticle technologies for AD treatment, including liposomes, polymeric, inorganic, and biomimetic nanoparticles. These nanoparticles improve drug delivery across the blood-brain barrier, improve stability and bioavailability, and enable targeted delivery to affected brain regions. Functionalization strategies further enhance their therapeutic potential. Multifunctional nanoparticles combining therapeutic and diagnostic properties offer theranostic approaches. While progress has been made, challenges related to safety, targeting precision, and clinical translation remain. Future perspectives emphasize the need for collaborative efforts to optimize nanoparticle design, conduct rigorous studies, and accelerate the development of effective nanotherapeutics. With continued innovation, nanoparticle-based delivery systems hold great promise for revolutionizing AD treatment.

Highly BBB-permeable nanomedicine reverses neuroapoptosis and neuroinflammation to treat Alzheimer's disease

The prevalence of Alzheimer's disease (AD) is increasing globally due to population aging. However, effective clinical treatment strategies for AD still remain elusive. The mechanisms underlying AD onset and the interplay between its pathological factors have so far been unclear. Evidence indicates that AD progression is ultimately driven by neuronal loss, which in turn is caused by neuroapoptosis and neuroinflammation. Therefore, the inhibition of neuroapoptosis and neuroinflammation could be a useful anti-AD strategy. Nonetheless, the delivery of active drug agents into the brain parenchyma is hindered by the blood-brain barrier (BBB). To address this challenge, we fabricated a black phosphorus nanosheet (BP)-based methylene blue (MB) delivery system (BP-MB) for AD therapy. After confirming the successful preparation of BP-MB, we proved that its BBB-crossing ability was enhanced under near-infrared light irradiation. In vitro pharmacodynamics analysis revealed that BP and MB could synergistically scavenge excessive reactive oxygen species (ROS) in okadaic acid (OA)-treated PC12 cells and lipopolysaccharide (LPS)-treated BV2 cells, thus efficiently reversing neuroapoptosis and neuroinflammation. To study in vivo pharmacodynamics, we established a mouse model of AD mice, and behavioral tests confirmed that BP-MB treatment could successfully improve cognitive function in these animals. Notably, the results of pathological evaluation were consistent with those of the in vitro assays. The findings demonstrated that BP-MB could scavenge excessive ROS and inhibit Tau hyperphosphorylation, thereby alleviating downstream neuroapoptosis and regulating the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Overall, this study highlights the therapeutic potential of a smart nanomedicine with the capability of reversing neuroapoptosis and neuroinflammation for AD treatment.

Cationic Surface Charge Engineering of Recombinant Transthyretin Remarkably Increases the Inhibitory Potency Against Amyloid β-Protein Fibrillogenesis

The deposition of amyloid β-protein (Aβ) in the brain is the main pathogenesis of Alzheimer's disease (AD). The development of potent inhibitors against Aβ aggregation is one of the effective strategies to combat AD. Endogenous transthyretin (TTR) can inhibit Aβ fibrillization via hydrophobic interactions, but its weak inhibitory potency hinders its application in AD therapy. Here, different recombinant TTRs were designed by cationic surface charge engineering. Compared with TTR, all positively charged recombinant TTRs showed enhanced capability in inhibiting Aβ aggregation, especially the recombinant protein obtained by mutating the acidic amino acid in TTR to arginine (TTR-nR) exhibited excellent inhibitory effect. Among them, TTR-7R remarkably increased the inhibitory potency against Aβ, which could effectively inhibit Aβ40 fibrillization at a very low concentration (0.5 μM). In addition, TTR-7R increased cultured cell viability from 62% to 89%, scavenged amyloid plaques in AD nematodes, and prolonged nematode lifespan by 5 d at 2 μM. Thermodynamic studies demonstrated that TTR-7R, enriching in positive charges, presented hydrophobic interactions and enhanced electrostatic interactions with Aβ40, leading to a significantly enhanced inhibitory capacity of TTR-7R. The research provided insights into the development of efficient recombinant protein inhibitors for AD treatment.

Di-caffeoylquinic acid: a potential inhibitor for amyloid-beta aggregation

Alzheimer's disease (AD) remains a challenging neurodegenerative disorder with limited therapeutic success. Traditional Chinese Medicine (TCM), as a promising new source for AD, still requires further exploration to understand its complex components and mechanisms. Here, focused on addressing Aβ (1-40) aggregation, a hallmark of AD pathology, we employed a Thioflavin T fluorescence labeling method for screening the active molecular library of TCM which we established. Among the eight identified, 1,3-di-caffeoylquinic acid emerged as the most promising, exhibiting a robust binding affinity with a KD value of 26.7 nM. This study delves into the molecular intricacies by utilizing advanced techniques, including two-dimensional (2D) 15N-1H heteronuclear single quantum coherence nuclear magnetic resonance (NMR) and molecular docking simulations. These analyses revealed that 1,3-di-caffeoylquinic acid disrupts Aβ (1-40) self-aggregation by interacting with specific phenolic hydroxyl and amino acid residues, particularly at Met-35 in Aβ (1-40). Furthermore, at the cellular level, the identified compounds, especially 1,3-di-caffeoylquinic acid, demonstrated low toxicity and exhibited therapeutic potential by regulating mitochondrial membrane potential, reducing cell apoptosis, and mitigating Aβ (1-40)-induced cellular damage. This study presents a targeted exploration of catechol compounds with implications for effective interventions in AD and sheds light on the intricate molecular mechanisms underlying Aβ (1-40) aggregation disruption.

Multifunctional Nanocarrier for Synergistic Treatment of Alzheimer's Disease by Inhibiting β-Amyloid Aggregation and Scavenging Reactive Oxygen Species

The excessive depositions of β-amyloid (Aβ) and abnormal level of reactive oxygen species (ROS) are considered as the important pathogenic factors of Alzheimer's disease (AD). Strategies targeting only one of them have no obvious effects in clinic. In this study, a multifunctional nanocarrier CICe@M-K that crosses the blood-brain barrier (BBB) efficiently was developed for inhibiting Aβ aggregation and scavenging ROS synchronously. Antioxidant curcumin (Cur) and photosensitizer IR780 were loaded in mesoporous silica nanomaterials (MSNs). Their surfaces were grafted with cerium oxide nanoparticles (CeO2 NPs) and a short peptide K (CKLVFFAED). Living imaging showed that CICe@M-K was mainly distributed in the brain, liver, and kidneys, indicating CICe@M-K crossed BBB efficiently and accumulated in brain. After the irradiation of 808 nm laser, Cur was continuously released. Both of Cur and the peptide K can recognize and bind to Aβ through multiple interaction including π-π stacking interaction, hydrophobic interaction, and hydrogen bond, inhibiting Aβ aggregation. On the other hand, Cur and CeO2 NPs cooperate to relieve the oxidative stress in the brains by scavenging ROS. In vivo assays showed that the CICe@M-K could diminish Aβ depositions, alleviate oxidative stress, and improve cognitive ability of the APP/PS1 AD mouse model, which demonstrated that CICe@M-K is a potential agent for AD treatment.

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

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

Interactions between nanoparticles and pathological changes of vascular in Alzheimer's disease

Emerging evidence suggests that vascular pathological changes play a pivotal role in the pathogenesis of Alzheimer's disease (AD). The dysfunction of the cerebral vasculature occurs in the early course of AD, characterized by alterations in vascular morphology, diminished cerebral blood flow (CBF), impairment of the neurovascular unit (NVU), vasculature inflammation, and cerebral amyloid angiopathy. Vascular dysfunction not only facilitates the influx of neurotoxic substances into the brain, triggering inflammation and immune responses but also hampers the efflux of toxic proteins such as Aβ from the brain, thereby contributing to neurodegenerative changes in AD. Furthermore, these vascular changes significantly impact drug delivery and distribution within the brain. Therefore, developing targeted delivery systems or therapeutic strategies based on vascular alterations may potentially represent a novel breakthrough in AD treatment. This review comprehensively examines various aspects of vascular alterations in AD and outlines the current interactions between nanoparticles and pathological changes of vascular.

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.

Lead Identification Through In Silico Studies: Targeting Acetylcholinesterase Enzyme Against Alzheimer's Disease

AIMS

In this work, we aimed to acquire the best potential small molecule for Alzheimer's disease (AD) treatment using different models in Biovia Discovery Studio to identify new potential inhibitors of acetylcholinesterase (AChE) via in silico studies.

BACKGROUND

The prevalence of cognitive impairment-related neurodegenerative disorders, such as AD, has been observed to escalate rapidly. However, we still know little about the underlying functions, outcome predictors, or intervention targets causing AD.

OBJECTIVES

The objective of the study was to optimize and identify the lead compound to target AChE against Alzheimer's disease.

METHODS

Different in silico studies were employed, including the pharmacophore model, virtual screening, molecular docking, de novo evolution model, and molecular dynamics.

RESULTS

The pharmacophoric features of AChE inhibitors were determined by ligand-based pharmacophore models and 3D QSAR pharmacophore generation. Further validation of the best pharmacophore model was done using the cost analysis method, Fischer's randomization method, and test set. The molecules that harmonized the best pharmacophore model with the estimated activity < 1 nM and ADMET parameters were filtered, and 12 molecules were subjected to molecular docking studies to obtain binding energy. 3vsp_EK8_1 secured the highest binding energy of 65.60 kcal/mol. Further optimization led to a 3v_Evo_4 molecule with a better binding energy of 70.17 kcal/mol. The molecule 3v_evo_4 was subjected to 100 ns molecular simulation compared to donepezil, which showed better stability at the binding site.

CONCLUSION

A lead compound, 3v_Evo_4 molecule, was identified to inhibit AChE, and it could be further studied to develop as a drug with better efficacy than the existing available drugs for treating AD.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Retinal Microenvironment-Protected Rhein-GFFYE Nanofibers Attenuate Retinal Ischemia-Reperfusion Injury via Inhibiting Oxidative Stress and Regulating Microglial/Macrophage M1/M2 Polarization

Retinal ischemia is involved in the occurrence and development of various eye diseases, including glaucoma, diabetic retinopathy, and central retinal artery occlusion. To the best of our knowledge, few studies have reported self-assembling peptide natural products for the suppression of ocular inflammation and oxidative stress. Herein, a self-assembling peptide GFFYE is designed and synthesized, which can transform the non-hydrophilicity of rhein into an amphiphilic sustained-release therapeutic agent, and rhein-based therapeutic nanofibers (abbreviated as Rh-GFFYE) are constructed for the treatment of retinal ischemia-reperfusion (RIR) injury. Rh-GFFYE significantly ameliorates oxidative stress and inflammation in an in vitro oxygen-glucose deprivation (OGD) model of retinal ischemia and a rat model of RIR injury. Rh-GFFYE also significantly enhances retinal electrophysiological recovery and exhibits good biocompatibility. Importantly, Rh-GFFYE also promotes the transition of M1-type macrophages to the M2 type, ultimately altering the pro-inflammatory microenvironment. Further investigation of the treatment mechanism indicates that Rh-GFFYE activates the PI3K/AKT/mTOR signaling pathway to reduce oxidative stress and inhibits the NF-κB and STAT3 signaling pathways to affect inflammation and macrophage polarization. In conclusion, the rhein-loaded nanoplatform alleviates RIR injury by modulating the retinal microenvironment. The findings are expected to promote the clinical application of hydrophobic natural products in RIR injury-associated eye diseases.

Design of aggregation-induced emission-active fluorogen-based nanoparticles for imaging and scavenging Alzheimer's β-amyloid by photo-oxygenation

Photo-oxygenation has emerged as an effective modality for scavenging Alzheimer's amyloid-β (Aβ) plaques. However, limitations of the current photo-oxidants, such as low Aβ-targeting and single functionality, hinder the scavenging of Aβ plaques via photo-oxygenation. Herein, based on an aggregation-induced emission (AIE)-active fluorogen (named TPMD), we designed AIE photo-oxidant nanoparticles (T-LD NPs) for Aβ imaging, inhibition, and disaggregation. The T-LD NPs were prepared by the assembly of hydrophobic TPMD with an Aβ-targeting peptide (LPPFD, L) conjugated amphiphilic polymer (DSPE-PEG). Such T-LD NPs could specifically label Aβ plaques for image-guided therapy. Under laser irradiation, T-LD NPs generated a plethora of reactive oxygen species (ROS), including 1O2, ˙OH, and O2˙-, to oxygenate Aβ species, leading to the potent inhibition of Aβ fibrillization, and significant alleviation of Aβ-mediated neurotoxicity (36% to 10% at 20 μg mL-1). Notably, T-LD NPs could rapidly disaggregate mature Aβ fibrils into fractured β-sheet rich aggregates via photo-oxygenation, resulting in alleviated cytotoxicity. In vivo studies revealed that the photo-activated T-LD NPs scavenged amyloid plaques in the transgenic C. elegans strain CL2006 and extended the lifespan by 4 days. Taken together, this multifunctional T-LD NP integrated Aβ-targeting, near-infrared fluorescence imaging, and photo-oxygenation, provides a new strategy for the development of multifunctional AIE photo-oxidants for the treatment of Alzheimer's disease.

Functionalization of and through Melanin: Strategies and Bio-Applications

A unique feature of nanoparticles for bio-application is the ease of achieving multi-functionality through covalent and non-covalent functionalization. In this way, multiple therapeutic actions, including chemical, photothermal and photodynamic activity, can be combined with different bio-imaging modalities, such as magnetic resonance, photoacoustic, and fluorescence imaging, in a theragnostic approach. In this context, melanin-related nanomaterials possess unique features since they are intrinsically biocompatible and, due to their optical and electronic properties, are themselves very efficient photothermal agents, efficient antioxidants, and photoacoustic contrast agents. Moreover, these materials present a unique versatility of functionalization, which makes them ideal for the design of multifunctional platforms for nanomedicine integrating new functions such as drug delivery and controlled release, gene therapy, or contrast ability in magnetic resonance and fluorescence imaging. In this review, the most relevant and recent examples of melanin-based multi-functionalized nanosystems are discussed, highlighting the different methods of functionalization and, in particular, distinguishing pre-functionalization and post-functionalization. In the meantime, the properties of melanin coatings employable for the functionalization of a variety of material substrates are also briefly introduced, especially in order to explain the origin of the versatility of melanin functionalization. In the final part, the most relevant critical issues related to melanin functionalization that may arise during the design of multifunctional melanin-like nanoplatforms for nanomedicine and bio-application are listed and discussed.