Methotraxate-Loaded Hybrid Nanoconstructs Target Vascular Lesions and Inhibit Atherosclerosis Progression in ApoE-/- Mice

Inflammation and immunomodulatory therapies influence the relationship between ATP-binding cassette A1 membrane transporter-mediated cholesterol efflux capacity and coronary atherosclerosis in rheumatoid arthritis

Objectives

High-density lipoprotein (HDL) removes cholesterol from cells in atherosclerotic lesions, a function known as cholesterol efflux capacity (CEC). ATP-binding-cassette A1 (ABCA1) membrane transporter starts cholesterol transfer from macrophages to HDL particles. In rheumatoid arthritis (RA), methotrexate and biologic disease modifying drugs (bDMARDs) are atheroprotective whereas corticosteroids and C-reactive protein (CRP) are proatherogenic. We evaluated the influence of these factors on the relationship of ABCA1-CEC with atherosclerosis and cardiovascular events.

Methods

Atherosclerosis was evaluated with computed tomography angiography in 140 patients with RA and repeated in 99 after 6.9 ± 0.3 years. Events including acute coronary syndromes, stroke, cardiovascular death, claudication, revascularization, and heart failure were recorded. ABCA1-CEC was quantified in J774A.1 murine macrophages and reported as percentage of effluxed over intracellular cholesterol.

Results

Higher ABCA1-CEC associated with (i) more calcified plaques at baseline only in patients with CRP>7 mg/L (median) (p-interaction = 0.001) and methotrexate nonusers (p-interaction = 0.037), and more partially-calcified plaques only in bDMARD nonusers (p-interaction = 0.029); (ii) fewer new calcified plaques in patients with below-median but not higher time-averaged CRP (p-interaction = 0.028); (iii) fewer new total and calcified plaques in prednisone unexposed but not patients exposed to prednisone during follow-up (p-interaction = 0.034 and 0.004) and (iv) more new plaques in baseline bDMARD nonusers and fewer in bDMARD users (p-interaction ≤ 0.001). Also, ABCA1-CEC associated with greater cardiovascular risk only in baseline prednisone users (p-interaction = 0.027).

Conclusion

ABCA1-CEC associated with decreased atherosclerosis in patients with below-median baseline and time-averaged CRP and bDMARD use. Conversely, ABCA1-CEC associated with increased plaque in those with higher CRP, corticosteroid users, methotrexate nonusers, and bDMARD nonusers. While in well-treated and controlled disease ABCA1-CEC appears atheroprotective, in uncontrolled RA its action may be masked or fail to counteract the inflammation-driven proatherogenic state.

Advances in drug delivery to atherosclerosis: Investigating the efficiency of different nanomaterials employed for different type of drugs

Atherosclerosis is the build-up of fatty deposits in the arteries, which is the main underlying cause of cardiovascular diseases and the leading cause of global morbidity and mortality. Current pharmaceutical treatment options are unable to effectively treat the plaque in the later stages of the disease. Instead, they are aimed at resolving the risk factors. Nanomaterials and nanoparticle-mediated therapies have become increasingly popular for the treatment of atherosclerosis due to their targeted and controlled release of therapeutics. In this review, we discuss different types of therapeutics used to treat this disease and focus on the different nanomaterial strategies employed for the delivery of these drugs, enabling the effective and efficient resolution of the atherosclerotic plaque. The ideal nanomaterial strategy for each drug type (e.g. statins, nucleic acids, small molecule drugs, peptides) will be comprehensively discussed.

NLRP3 inflammasome pathway in atherosclerosis: Focusing on the therapeutic potential of non-coding RNAs

NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome pathway has a critical role in the pathogenesis of atherosclerosis. Activation of this pathway is implicated in the subendothelial inflammation and atherosclerosis progression. The NLRP3 inflammasome are cytoplasmic sensors with the distinct capacity to identify a wide range of inflammation-related signals, which enhance NLRP3 inflammasome assembly and allow it to trigger inflammation. This pathway is triggered by a variety of intrinsic signals which exist in atherosclerotic plaques, like cholesterol crystals and oxidized LDL. Further pharmacological findings indicated that NLRP3 inflammasome enhanced caspase-1-mediated secretion of pro-inflammatory mediators like interleukin (IL)- 1β/18. Newly published cutting-edge studies suggested that non-coding RNAs (ncRNAs) including microRNAs (miRNAs, miRs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) are major modulators of NLRP3 inflammasome in atherosclerosis. Therefore, in this review, we aimed to discuss the NLRP3 inflammasome pathway, biogenesis of ncRNAs as well as the modulatory role of ncRNAs in regulating the various mediators of NLRP3 inflammasome pathway including TLR4, NF-kB, NLRP3, and caspase 1. We also discussed the importance of NLRP3 inflammasome pathway-related ncRNAs as a diagnostic biomarker in atherosclerosis and current therapeutics in the modulation of NLRP3 inflammasome in atherosclerosis. Finally, we speak about the limitations and future prospects of ncRNAs in regulating inflammatory atherosclerosis via the NLRP3 inflammasome pathway.

Methotrexate and cardiovascular prevention: an appraisal of the current evidence

New evidence continues to accumulate regarding a significant association between excessive inflammation and dysregulated immunity (local and systemic) and the risk of cardiovascular events in different patient cohorts. Whilst research has sought to identify novel atheroprotective therapies targeting inflammation and immunity, several marketed drugs for rheumatological conditions may serve a similar purpose. One such drug, methotrexate, has been used since 1948 for treating cancer and, more recently, for a wide range of dysimmune conditions. Over the last 30 years, epidemiological and experimental studies have shown that methotrexate is independently associated with a reduced risk of cardiovascular disease, particularly in rheumatological patients, and exerts several beneficial effects on vascular homeostasis and blood pressure control. This review article discusses the current challenges with managing cardiovascular risk and the new frontiers offered by drug discovery and drug repurposing targeting inflammation and immunity with a focus on methotrexate. Specifically, the article critically appraises the results of observational, cross-sectional and intervention studies investigating the effects of methotrexate on overall cardiovascular risk and individual risk factors. It also discusses the putative molecular mechanisms underpinning the atheroprotective effects of methotrexate and the practical advantages of using methotrexate in cardiovascular prevention, and highlights future research directions in this area.

Comparison of Cell-based and Nanoparticle-based Therapeutics in Treating Atherosclerosis

Today, cardiovascular diseases are among the biggest public health threats worldwide. Atherosclerosis, a chronic inflammatory disease with complex aetiology and pathogenesis, predispose many of these conditions, including the high mortality rate-causing ischaemic heart disease and stroke. Nevertheless, despite the alarming prevalence and absolute death rate, established treatments for atherosclerosis are unsatisfactory in terms of efficacy, safety, and patient acceptance. The rapid advancement of technologies in healthcare research has paved new treatment approaches, namely cell-based and nanoparticle-based therapies, to overcome the limitations of conventional therapeutics. This paper examines the different facets of each approach, discusses their principles, strengths, and weaknesses, analyses the main targeted pathways and their contradictions, provides insights on current trends as well as highlights any unique mechanisms taken in recent years to combat the progression of atherosclerosis.

Advances in imaging and treatment of atherosclerosis based on organic nanoparticles

Atherosclerosis, a systemic chronic inflammatory disease, can lead to thrombosis and vascular occlusion, thereby inducing a series of serious vascular diseases. Currently, distinguishing unstable plaques early and achieving more effective treatment are the two main clinical concerns in atherosclerosis. Organic nanoparticles have great potential in atherosclerotic imaging and treatment, showing superior biocompatibility, drug-loading capacity, and synthesis. This article illustrates the process of atherosclerosis onset and the key targeted cells, then systematically summarizes recent progress made in organic nanoparticle-based imaging of different types of targeted cells and therapeutic methods for atherosclerosis, including optical and acoustic-induced therapy, drug delivery, gene therapy, and immunotherapy. Finally, we discuss the major impediments that need to be addressed in future clinical practice. We believe this article will help readers to develop a comprehensive and in-depth understanding of organic nanoparticle-based atherosclerotic imaging and treatment, thus advancing further development of anti-atherosclerosis therapies.

Macrophage-targeted nanomedicine for the diagnosis and management of atherosclerosis

Atherosclerosis is the primary cause of cardiovascular diseases, such as myocardial infarction and stroke, which account for the highest death toll worldwide. Macrophage is the major contributor to atherosclerosis progression, and therefore, macrophage-associated pathological process is considered an extremely important target for the diagnosis and treatment of atherosclerosis. However, the existing clinical strategies still have many bottlenecks and challenges in atherosclerosis’s early detection and management. Nanomedicine, using various nanoparticles/nanocarriers for medical purposes, can effectively load therapeutic agents, significantly improve their stability and accurately deliver them to the atherosclerotic plaques. In this review, we summarized the latest progress of the macrophage-targeted nanomedicine in the diagnosis and treatment of atherosclerosis, and their potential applications and clinical benefits are also discussed.

Nanoparticles in the diagnosis and treatment of vascular aging and related diseases

Aging-induced alternations of vasculature structures, phenotypes, and functions are key in the occurrence and development of vascular aging-related diseases. Multiple molecular and cellular events, such as oxidative stress, mitochondrial dysfunction, vascular inflammation, cellular senescence, and epigenetic alterations are highly associated with vascular aging physiopathology. Advances in nanoparticles and nanotechnology, which can realize sensitive diagnostic modalities, efficient medical treatment, and better prognosis as well as less adverse effects on non-target tissues, provide an amazing window in the field of vascular aging and related diseases. Throughout this review, we presented current knowledge on classification of nanoparticles and the relationship between vascular aging and related diseases. Importantly, we comprehensively summarized the potential of nanoparticles-based diagnostic and therapeutic techniques in vascular aging and related diseases, including cardiovascular diseases, cerebrovascular diseases, as well as chronic kidney diseases, and discussed the advantages and limitations of their clinical applications.

Inflammation and atherosclerosis: signaling pathways and therapeutic intervention

Atherosclerosis is a chronic inflammatory vascular disease driven by traditional and nontraditional risk factors. Genome-wide association combined with clonal lineage tracing and clinical trials have demonstrated that innate and adaptive immune responses can promote or quell atherosclerosis. Several signaling pathways, that are associated with the inflammatory response, have been implicated within atherosclerosis such as NLRP3 inflammasome, toll-like receptors, proprotein convertase subtilisin/kexin type 9, Notch and Wnt signaling pathways, which are of importance for atherosclerosis development and regression. Targeting inflammatory pathways, especially the NLRP3 inflammasome pathway and its regulated inflammatory cytokine interleukin-1β, could represent an attractive new route for the treatment of atherosclerotic diseases. Herein, we summarize the knowledge on cellular participants and key inflammatory signaling pathways in atherosclerosis, and discuss the preclinical studies targeting these key pathways for atherosclerosis, the clinical trials that are going to target some of these processes, and the effects of quelling inflammation and atherosclerosis in the clinic.

LIFU-responsive nanomedicine enables acoustic droplet vaporization-induced apoptosis of macrophages for stabilizing vulnerable atherosclerotic plaques

Due to the high risk of tearing and rupture, vulnerable atherosclerotic plaques would induce serious cardiovascular and cerebrovascular diseases. Despite the available clinical methods can evaluate the vulnerability of plaques and specifically treat vulnerable plaques before a cardiovascular event, but the efficiency is still low and undesirable. Herein, we rationally design and engineer the low-intensity focused ultrasound (LIFU)-responsive FPD@CD nanomedicine for the highly efficient treatment of vulnerable plaques by facilely loading phase transition agent perfluorohexane (PFH) into biocompatible PLGA-PEG-PLGA nanoparticles (PPP NPs) and then attaching dextran sulphate (DS) onto the surface of PPP NPs for targeting delivery. DS, as a typical macrophages-targeted molecule, can achieve the precise vaporization of NPs and subsequently controllable apoptosis of RAW 264.7 macrophages as induced by acoustic droplet vaporization (ADV) effect. In addition, the introduction of DiR and Fe₃O₄ endows nanomedicine with near-infrared fluorescence (NIRF) and magnetic resonance (MR) imaging capabilities. The engineered FPD@CD nanomedicine that uses macrophages as therapeutic targets achieve the conspicuous therapeutic effect of shrinking vulnerable plaques based on in vivo and in vitro evaluation outcomes. A reduction of 49.4% of vascular stenosis degree in gross pathology specimens were achieved throughout the treatment period. This specific, efficient and biosafe treatment modality potentiates the biomedical application in patients with cardiovascular and cerebrovascular diseases based on the relief of the plaque rupture concerns.

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A new nanomedicine-enabled treatment strategy has been developed for treating vulnerable plaques by employing ADV.

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The optimal treatment conditions for ADV have been explored, including LIFU irradiation power intensity and plaque stability.

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The underlying mechanism of nanomedicine-enabled ADV in the treatment of vulnerable plaques has been studied systematically.

Macrophage-targeted nanomedicine for the diagnosis and treatment of atherosclerosis

Nanotechnology could improve our understanding of the pathophysiology of atherosclerosis and contribute to the development of novel diagnostic and therapeutic strategies to further reduce the risk of cardiovascular disease. Macrophages have key roles in atherosclerosis progression and, therefore, macrophage-associated pathological processes are important targets for both diagnostic imaging and novel therapies for atherosclerosis. In this Review, we highlight efforts in the past two decades to develop imaging techniques and to therapeutically manipulate macrophages in atherosclerotic plaques with the use of rationally designed nanoparticles. We review the latest progress in nanoparticle-based imaging modalities that can specifically target macrophages. Using novel molecular imaging technology, these modalities enable the identification of advanced atherosclerotic plaques and the assessment of the therapeutic efficacy of medical interventions. Additionally, we provide novel perspectives on how macrophage-targeting nanoparticles can deliver a broad range of therapeutic payloads to atherosclerotic lesions. These nanoparticles can suppress pro-atherogenic macrophage processes, leading to improved resolution of inflammation and stabilization of plaques. Finally, we propose future opportunities for novel diagnostic and therapeutic strategies and provide solutions to challenges in this area for the purpose of accelerating the clinical translation of nanomedicine for the treatment of atherosclerotic vascular disease.

Nanotechnology for Targeted Therapy of Atherosclerosis

Atherosclerosis is the major cause of heart attack and stroke that are the leading causes of death in the world. Nanomedicine is a powerful tool that can be engineered to target atherosclerotic plaques for therapeutic and diagnosis purposes. In this review, advances in designing nanoparticles with therapeutic effects on atherosclerotic plaques known as atheroprotective nanomedicine have been summarized to stimulate further development and future translation.

Innovative nanotools for vascular drug delivery: the atherosclerosis case study

Cardiovascular diseases are the leading cause of mortality in the Western world. Among them, atherosclerosis represents one of the most common diseases in the modern society due to a common sedentary lifestyle, high-fat diet, and smoking. In the near future, a new approach could potentially improve the therapy of vascular pathologies, where to date the non-specific treatments present several limitations, such as poor biodistribution, quick elimination from the body, and undesired side-effects. In this field, nanotechnology has a great potential for the therapy and diagnosis of atherosclerosis with more and more recent and innovative publications. This review is a critical analysis of the results reported in the literature regarding the different and possible new approaches for the therapy and diagnosis of atherosclerosis.

The role and transformative potential of IL-19 in atherosclerosis

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Traditionally, IL-19 was thought to be expressed in only immune cells, but studies revealed that IL-19 is also expressed in multiple atherosclerotic plaque cell types, but not normal arteries, in humans and mice. IL-19 reduces the development of atherosclerosis via multiple mechanisms, including balancing cholesterol metabolism; enhancing Th2 immune cell polarization; reducing the inflammatory response; and reducing the proliferation, migration and chemotaxis of vascular smooth muscle cells (VSMCs). Clinical and/or animal studies have primarily aimed to achieve regression and/or stabilization of atherosclerotic plaques, with regression in particular indicating a very good drug response. Most antiatherosclerotic drugs in current clinical use, including atorvastatin and alirocumab, target hyperlipidemia. Several other drugs have also been investigated in clinical trials as anti-inflammatory agents; the development of some of these agents has been terminated (canakinumab, darapladib, varespladib, losmapimod, atreleuton, setileuton, PF-04191834, veliflapon, and methotrexate), but others remain in development (ziltivekimab, tocilizumab, Somalix, IFM-2427, anakinra, mesenchymal stem cells (MSCs), colchicine, everolimus, allopurinol, and montelukast). Most of the tested drugs have shown a limited ability to reverse atherosclerosis in animal studies. Interestingly, recombinant IL-19 (rIL-19) was shown to reduce atherosclerosis development in a time- and dose-dependent manner. A low dose of rIL-19 (1 ng/g/day) reduced aortic arch and root plaque areas by 70.1% and 32.1%, respectively, in LDLR^-/- mice. At 10 ng/g/day, rIL-19 completely eliminated atherosclerotic plaques. There were no sex differences in the effects of rIL-19 on atherosclerotic mice. Thus, low-dose rIL-19 is an effective antiatherosclerotic agent, in addition to its efficacy in intimal hyperplasia, spinal cord injury, stroke, and multiple sclerosis. We propose that IL-19 is a promising biomarker and target for the diagnosis and treatment of atherosclerosis. This review considers the role and mechanism of action of IL-19 in atherosclerosis and discusses whether IL-19 is a potential therapeutic target for this condition.

Curcumin-Loaded Nanoparticles Impair the Pro-Tumor Activity of Acid-Stressed MSC in an In Vitro Model of Osteosarcoma

In the tumor microenvironment, mesenchymal stromal cells (MSCs) are key modulators of cancer cell behavior in response to several stimuli. Intratumoral acidosis is a metabolic trait of fast-growing tumors that can induce a pro-tumorigenic phenotype in MSCs through the activation of the NF-κB-mediated inflammatory pathway, driving tumor clonogenicity, invasion, and chemoresistance. Recent studies have indicated that curcumin, a natural ingredient extracted from Curcuma longa, acts as an NF-κB inhibitor with anti-inflammatory properties. In this work, highly proliferating osteosarcoma cells were used to study the ability of curcumin to reduce the supportive effect of MSCs when stimulated by acidosis. Due to the poor solubility of curcumin in biological fluids, we used spherical polymeric nanoparticles as carriers (SPN-curc) to optimize its uptake by MSCs. We showed that SPN-curc inhibited the release of inflammatory cytokines (IL6 and IL8) by acidity-stimulated MSCs at a higher extent than by free curcumin. SPN-curc treatment was also successful in blocking tumor stemness, migration, and invasion that were driven by the secretome of acid-stressed MSCs. Overall, these data encourage the use of lipid–polymeric nanoparticles encapsulating NF-κB inhibitors such as curcumin to treat cancers whose progression is stimulated by an activated mesenchymal stroma.

Molecular and Nonmolecular Imaging of Macrophages in Atherosclerosis

Atherosclerosis is a major cause of ischemic heart disease, and the increasing medical burden associated with atherosclerotic cardiovascular disease has become a major public health concern worldwide. Macrophages play an important role in all stages of the dynamic progress of atherosclerosis, from its initiation and lesion expansion increasing the vulnerability of plaques, to the formation of unstable plaques and clinical manifestations. Early imaging can identify patients at risk of coronary atherosclerotic disease and its complications, enabling preventive measures to be initiated. Recent advances in molecular imaging have involved the noninvasive and semi-quantitative targeted imaging of macrophages and their related molecules in vivo, which can detect atheroma earlier and more accurately than conventional imaging. Multimodal imaging integrates vascular structure, function, and molecular imaging technology to achieve multi-dimensional imaging, which can be used to comprehensively evaluate blood vessels and obtain clinical information based on anatomical structure and molecular level. At the same time, the rapid development of nonmolecular imaging technologies, such as intravascular imaging, which have the unique advantages of having intuitive accuracy and providing rich information to identify macrophage inflammation and inform targeted personalized treatment, has also been seen. In this review, we highlight recent methods and research hotspots in molecular and nonmolecular imaging of macrophages in atherosclerosis that have enormous potential for rapid clinical application.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

Modulating Lipoprotein Transcellular Transport and Atherosclerotic Plaque Formation in ApoE-/- Mice via Nanoformulated Lipid-Methotrexate Conjugates

Macrophage inflammation and maturation into foam cells, following the engulfment of oxidized low-density lipoproteins (oxLDL), are major hallmarks in the onset and progression of atherosclerosis. Yet, chronic treatments with anti-inflammatory agents, such as methotrexate (MTX), failed to modulate disease progression, possibly for the limited drug bioavailability and plaque deposition. Here, MTX-lipid conjugates, based on 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), were integrated in the structure of spherical polymeric nanoparticles (MTX-SPNs) or intercalated in the lipid bilayer of liposomes (MTX-LIP). Although, both nanoparticles were colloidally stable with an average diameter of ∼200 nm, MTX-LIP exhibited a higher encapsulation efficiency (>70%) and slower release rate (∼50% at 10 h) compared to MTX-SPN. In primary bone marrow derived macrophages (BMDMs), MTX-LIP modulated the transcellular transport of oxLDL more efficiently than free MTX mostly by inducing a 2-fold overexpression of ABCA1 (regulating oxLDL efflux), while the effect on CD36 and SRA-1 (regulating oxLDL influx) was minimal. Furthermore, in BMDMs, MTX-LIP showed a stronger anti-inflammatory activity than free MTX, reducing the expression of IL-1β by 3-fold, IL-6 by 2-fold, and also moderately of TNF-α. In 28 days high-fat-diet-fed apoE-/- mice, MTX-LIP reduced the mean plaque area by 2-fold and the hematic amounts of RANTES by half as compared to free MTX. These results would suggest that the nanoenhanced delivery to vascular plaques of the anti-inflammatory DSPE-MTX conjugate could effectively modulate the disease progression by halting monocytes' maturation and recruitment already at the onset of atherosclerosis.

Atheroprotective effects of methotrexate via the inhibition of YAP/TAZ under disturbed flow

Background

Atherosclerosis preferentially develops in regions of disturbed flow (DF). Emerging evidence indicates that yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), which are both effectors of the Hippo pathway, sense different blood flow patterns and regulate atherosclerotic lesions. We previously found that methotrexate (MTX) reduces in-stent neoatherosclerosis, decreases the plaque burden, and has an effect on local fluid shear stress. Here, we investigated the atheroprotective effect of MTX under DF and the mechanisms underlying these properties.

Methods

Human umbilical vein endothelial cells (HUVECs) were subjected to biomechanical stretch using a parallel-plate flow system and treated with or without MTX at therapeutically relevant concentrations. Additionally, an extravascular device was used to induce DF in the left common carotid artery of C57BL/6 mice, followed by treatment with MTX or 0.9% saline. The artery was then assessed histopathologically after 4 weeks on a Western diet.

Results

We observed that MTX significantly inhibited DF-induced endothelial YAP/TAZ activation. Furthermore, it markedly decreased pro-inflammatory factor secretion and monocyte adhesion in HUVECs but had no effect on apoptosis. Mechanistically, AMPKa1 depletion attenuated these effects of MTX. Accordingly, MTX decreased DF-induced plaque formation, which was accompanied by YAP/TAZ downregulation in vivo.

Conclusions

Taken together, we conclude that MTX exerts protective effects via the AMP-dependent kinase (AMPK)-YAP/TAZ pathway. These results provide a basis for the prevention and treatment of atherosclerosis via the inhibition of YAP/TAZ.

The Therapeutic Potential of Nanoparticles to Reduce Inflammation in Atherosclerosis

Chronic inflammation is one of the main determinants of atherogenesis. The traditional medications for treatment of atherosclerosis are not very efficient in targeting atherosclerotic inflammation. Most of these drugs are non-selective, anti-inflammatory and immunosuppressive agents that have adverse effects and very limited anti-atherosclerotic effects, which limits their systemic administration. New approaches using nanoparticles have been investigated to specifically deliver therapeutic agents directly on atherosclerotic lesions. The use of drug delivery systems, such as polymeric nanoparticles, liposomes, and carbon nanotubes are attractive strategies, but some limitations exist. For instance, nanoparticles may alter the drug kinetics, based on the pathophysiological mechanisms of the diseases. In this review, we will update pathophysiological evidence for the use of nanoparticles to reduce inflammation and potentially prevent atherogenesis in different experimental models.

Paramagnetic Clusters of Mn3(O2CCH3)6(Bpy)2 in Polyacrylamide Nanobeads as a New Design Approach to a T1- T2 Multimodal Magnetic Resonance Imaging Contrast Agent

There is an increasing need for gadolinium-free magnetic resonance imaging (MRI) contrast agents, particularly for patients suffering from chronic kidney disease. Using a cluster-nanocarrier combination, we have identified a novel approach to the design of biomedical nanomaterials and report here the criteria for the cluster and the nanocarrier and the advantages of this combination. We have investigated the relaxivity of the following manganese oxo clusters: the parent cluster Mn₃(O₂CCH₃)₆(Bpy)₂ (1) where Bpy = 2,2'-bipyridine and three new analogs, Mn₃(O₂CC₆H₄CH═CH₂)₆(Bpy)₂ (2), Mn₃(O₂CC(CH₃)═CH₂)₆(Bpy)₂ (3), and Mn₃O(O₂CCH₃)₆(Pyr)₂ (4) where Pyr = pyridine. The parent cluster, Mn₃(O₂CCH₃)₆(Bpy)₂ (1), had impressive relaxivity ( r₁ = 6.9 mM^-1 s^-1, r₂ = 125 mM^-1 s^-1) and was found to be the most amenable for the synthesis of cluster-nanocarrier nanobeads. Using the inverse miniemulsion polymerization technique (1) in combination with the hydrophilic monomer acrylamide, we synthesized nanobeads (∼125 nm diameter) with homogeneously dispersed clusters within the polyacrylamide matrix (termed Mn₃Bpy-PAm). The nanobeads were surface-modified by co-polymerization with an amine-functionalized monomer. This enabled various postsynthetic modifications, for example, to attach a near-IR dye, Cyanine7, as well as a targeting agent. When evaluated as a potential multimodal MRI contrast agent, high relaxivity and contrast were observed with r₁ = 54.4 mM^-1 s^-1 and r₂ = 144 mM^-1 s^-1, surpassing T₁ relaxivity of clinically used Gd-DTPA chelates as well as comparable T₂ relaxivity to iron oxide microspheres. Physicochemical properties, cellular uptake, and impacts on cell viability were also investigated.

Targeting Inflammation With Nanosized Drug Delivery Platforms in Cardiovascular Diseases: Immune Cell Modulation in Atherosclerosis

Atherosclerosis (AS) is a disorder of large and medium-sized arteries; it consists in the formation of lipid-rich plaques in the intima and inner media, whose pathophysiology is mostly driven by inflammation. Currently available interventions and therapies for treating atherosclerosis are not always completely effective; side effects associated with treatments, mainly caused by immunodepression for anti-inflammatory molecules, limit the systemic administration of these and other drugs. Given the high degree of freedom in the design of nanoconstructs, in the last decades researchers have put high effort in the development of nanoparticles (NPs) formulations specifically designed for either drug delivery, visualization of atherosclerotic plaques, or possibly the combination of both these and other functionalities. Here we will present the state of the art of these subjects, the knowledge of which is necessary to rationally address the use of NPs for prevention, diagnosis, and/or treatment of AS. We will analyse the work that has been done on: (a) understanding the role of the immune system and inflammation in cardiovascular diseases, (b) the pathological and biochemical principles in atherosclerotic plaque formation, (c) the latest advances in the use of NPs for the recognition and treatment of cardiovascular diseases, (d) the cellular and animal models useful to study the interactions of NPs with the immune system cells.

Repurposing existing drugs for cardiovascular risk management: a focus on methotrexate

About 20% of patients with a history of atherosclerotic cardiovascular disease will experience further cardiovascular events despite maximal pharmacological treatment with cardioprotective drugs. This highlights the presence of residual cardiovascular risk in a significant proportion of patients and the need for novel, more effective therapies. These therapies should ideally target different pathophysiological pathways involved in the onset and the progression of atherosclerosis, particularly the inflammatory and immune pathways. Methotrexate is a first-line disease-modifying antirheumatic drug that is widely used for the management of autoimmune and chronic inflammatory disorders. There is some in vitro and in vivo evidence that methotrexate might exert a unique combination of anti-inflammatory, blood pressure lowering, and vasculoprotective effects. Pending the results of large prospective studies investigating surrogate end-points as well as morbidity and mortality, repurposing methotrexate for cardiovascular risk management might represent a cost-effective strategy with immediate public health benefits. This review discusses the current challenges in the management of cardiovascular disease; the available evidence on the effects of methotrexate on inflammation, blood pressure, and surrogate markers of arterial function; suggestions for future research directions; and practical considerations with the use of methotrexate in this context.

Nanotherapeutics for Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a devastating and fatal chronic lung disease. While current pharmacotherapies have improved patient quality of life, PAH drugs suffer from limitations in the form of short-term pharmacokinetics, instability, and poor organ specificity. Traditionally, nanotechnology-based delivery strategies have proven advantageous at increasing both circulation lifetimes of chemotherapeutics and accumulation in tumors due to enhanced permeability through fenestrated vasculature. Importantly, increased nanoparticle (NP) accumulation in diseased tissues has been observed pre-clinically in pathologies characterized by endothelial dysfunction and remodeled vasculature, including myocardial infarction and heart failure. Recently, this phenomenon has also been observed in preclinical models of PAH, leading to the exploration of NP-based drug delivery as a therapeutic modality in PAH. Herein, we discussed the advantages of NPs for efficacious treatment of PAH, including heightened therapeutic delivery to diseased lungs for increased drug bioavailability, as well as highlighted innovative nanotherapeutic approaches for PAH.

Local Delivery of miR-21 Stabilizes Fibrous Caps in Vulnerable Atherosclerotic Lesions

miRNAs are potential regulators of carotid artery stenosis and concordant vulnerable atherosclerotic plaques. Hence, we analyzed miRNA expression in laser captured micro-dissected fibrous caps of either ruptured or stable plaques (n = 10 each), discovering that miR-21 was significantly downregulated in unstable lesions. To functionally evaluate miR-21 in plaque vulnerability, miR-21 and miR-21/apolipoprotein-E double-deficient mice (Apoe-/-miR-21-/-) were assessed. miR-21-/- mice lacked sufficient smooth muscle cell proliferation in response to carotid ligation injury. When exposing Apoe-/-miR-21-/- mice to an inducible plaque rupture model, they presented with more atherothrombotic events (93%) compared with miR-21+/+Apoe-/- mice (57%). We discovered that smooth muscle cell fate in experimentally induced advanced lesions is steered via a REST-miR-21-REST feedback signaling pathway. Furthermore, Apoe-/-miR-21-/- mice presented with more pronounced atherosclerotic lesions, greater foam cell formation, and substantially higher levels of arterial macrophage infiltration. Local delivery of a miR-21 mimic using ultrasound-targeted microbubbles into carotid plaques rescued the vulnerable plaque rupture phenotype. In the present study, we identify miR-21 as a key modulator of pathologic processes in advanced atherosclerosis. Targeted, lesion site-specific overexpression of miR-21 can stabilize vulnerable plaques.

Ameliorating Amyloid-β Fibrils Triggered Inflammation via Curcumin-Loaded Polymeric Nanoconstructs

Inflammation is a common hallmark in several diseases, including atherosclerosis, cancer, obesity, and neurodegeneration. In Alzheimer's disease (AD), growing evidence directly correlates neuronal damage with inflammation of myeloid brain cells, such as microglia. Here, polymeric nanoparticles were engineered and characterized for the delivery of anti-inflammatory molecules to macrophages stimulated via direct incubation with amyloid-β fibers. 200 nm spherical polymeric nanoconstructs (SPNs) and 1,000 nm discoidal polymeric nanoconstructs (DPNs) were synthesized using poly(lactic-co-glycolic acid) (PLGA), polyethylene glycol (PEG), and lipid chains as building blocks. First, the internalization propensity in macrophages of both nanoparticles was assessed via cytofluorimetric and confocal microscopy analyses, demonstrating that SPNs are by far more rapidly taken up as compared to DPNs (99.6 ± 0.11 vs 14.4 ± 0.06%, within 24 h). Then, Curcumin-loaded SPNs (Curc-SPNs) were realized by encapsulating Curcumin, a natural anti-inflammatory molecule, within the PLGA core of SPNs. Finally, Curc-SPNs were shown to diminish up to 6.5-fold the production of pro-inflammatory cytokines-IL-1β; IL-6, and TNF-α-in macrophages stimulated via amyloid-β fibers. Although more sophisticated in vitro models and systematic analyses on the blood-brain barrier permeability are critically needed, these findings hold potential in the development of nanoparticles for modulating inflammation in AD.