Nanotechnology for Targeted Therapy of Atherosclerosis

Current targeting strategies and advanced nanoplatforms for atherosclerosis therapy

Atherosclerosis is one of the major causes of death worldwide, and it is closely related to many cardiovascular diseases, such as stroke, myocardial infraction and angina. Although traditional surgical and pharmacological interventions can effectively retard or slow down the progression of atherosclerosis, it is very difficult to prevent or even reverse this disease. In recent years, with the rapid development of nanotechnology, various nanoagents have been designed and applied to different diseases including atherosclerosis. The unique atherosclerotic microenvironment with signature biological components allows nanoplatforms to distinguish atherosclerotic lesions from normal tissue and to approach plaques specifically. Based on the process of atherosclerotic plaque formation, this review summarises the nanodrug delivery strategies for atherosclerotic therapy, trying to provide help for researchers to understand the existing atherosclerosis management approaches as well as challenges and to reasonably design anti-atherosclerotic nanoplatforms.

The role of nanosystems in the delivery of glucose-lowering drugs for the preemption and treatment of diabetes-associated atherosclerosis

Diabetes is one of the most prevalent diseases worldwide. In recent decades, type-2 diabetes has become increasingly common, particularly in younger individuals. Diabetes leads to many vascular complications, including atherosclerosis. Atherosclerosis is a cardiovascular disease characterized by lipid-rich plaques within the vasculature. Plaques develop over time, restricting blood flow, and can, therefore, be the underlying cause of major adverse cardiovascular events, including myocardial infarction and stroke. Diabetes and atherosclerosis are intrinsically linked. Diabetes is a metabolic syndrome that accelerates atherosclerosis and increases the risk of developing other comorbidities, such as diabetes-associated atherosclerosis (DAA). Gold standard antidiabetic medications focus on attenuating hyperglycemia. Though recent evidence suggests that glucose-lowering drugs may have broader applications, beyond diabetes management. This review mainly evaluates the role of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), such as liraglutide and semaglutide in DAA. These drugs mimic gut hormones (incretins), which inhibit glucagon secretion while stimulating insulin secretion, thus improving insulin sensitivity. This facilitates delayed gastric emptying and increased patient satiety; hence, they are also indicated for the treatment of obesity. GLP-1 RAs have significant cardioprotective effects, including decreasing low-density lipoprotein (LDL) cholesterol and triglycerides levels. Liraglutide and semaglutide have specifically been shown to decrease cardiovascular risk. Liraglutide has displayed a myriad of antiatherosclerotic properties, with the potential to induce plaque regression. This review aims to address how glucose-lowering medications can be applied to treat diseases other than diabetes. We specifically focus on how nanomedicines can be used for the site-specific delivery of antidiabetic medicines for the treatment of diabetes-associated atherosclerosis.

A multiscale modeling study of nanoparticle-based targeting therapy against atherosclerosis

Although researches on nanoparticle-based (NP-based) drug delivery system for atherosclerosis treatment have grown rapidly in recent years, there are limited studies in quantifying the effects of targeting drugs on plaque components and microenvironment. The purpose of the present study was to quantitatively assess the targeting therapeutic effects against atherosclerosis by establishing a multiscale mathematical model. The multiscale model involved subcellular, cellular and microenvironmental scales to simulate lipid catabolism, macrophage behaviors and dynamics of microenvironmental components, respectively. In vitro and in vivo experimental data were integrated into the mathematical model according to Bayesian statistics, in order to evaluate the therapeutic effects of a proposed NP-based platform for macrophage-specific delivery to simultaneously deliver SR-A siRNA (to reduce LDL uptake) and LXR-L (to stimulate cholesterol efflux). Dosage variation analysis was then performed to investigate the drug efficacy under varied dosage combinations of SR-A siRNA and LXR-L. The simulation results demonstrated that the dynamics of the microenvironmental components presented different developments in Untreated and Treated groups. We also found that the balance of lipid metabolism between uptake and efflux resulted in the improvement of lipid and inflammatory microenvironment, consequently in the plaque regression. In addition, the model predicted optimized dosage combinations according to the co-effect analysis of the two drugs on the lipid microenvironment. This study suggests that multiscale modeling can be a powerful quantitative tool for estimating the therapeutic effects of targeting drugs for plaque regression and designing the enhanced treatment strategies against atherosclerosis.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

Cardiovascular Tissue Engineering Models for Atherosclerosis Treatment Development

In the early years of tissue engineering, scientists focused on the generation of healthy-like tissues and organs to replace diseased tissue areas with the aim of filling the gap between organ demands and actual organ donations. Over time, the realization has set in that there is an additional large unmet need for suitable disease models to study their progression and to test and refine different treatment approaches. Increasingly, researchers have turned to tissue engineering to address this need for controllable translational disease models. We review existing and potential uses of tissue-engineered disease models in cardiovascular research and suggest guidelines for generating adequate disease models, aimed both at studying disease progression mechanisms and supporting the development of dedicated drug-delivery therapies. This involves the discussion of different requirements for disease models to test drugs, nanoparticles, and drug-eluting devices. In addition to realistic cellular composition, the different mechanical and structural properties that are needed to simulate pathological reality are addressed.

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.

Constructing Lipoparticles Capable of Endothelial Cell-Derived Exosome-Mediated Delivery of Anti-miR-33a-5p to Cultured Macrophages

Atherosclerosis is driven by intimal arterial macrophages accumulating cholesterol. Atherosclerosis also predominantly occurs in areas consisting of proinflammatory arterial endothelial cells. At time of writing, there are no available clinical treatments that precisely remove excess cholesterol from lipid-laden intimal arterial macrophages. Delivery of anti-miR-33a-5p to macrophages has been shown to increase apoAI-mediated cholesterol efflux via ABCA1 upregulation but delivering transgenes to intimal arterial macrophages is challenging due to endothelial cell barrier integrity. In this study, we aimed to test whether lipoparticles targeting proinflammatory endothelial cells can participate in endothelial cell-derived exosome exploitation to facilitate exosome-mediated transgene delivery to macrophages. We constructed lipoparticles that precisely target the proinflammatory endothelium and contain a plasmid that expresses XMOTIF-tagged anti-miR-33a-5p (LP-pXMoAntimiR33a5p), as XMOTIF-tagged small RNA demonstrates the capacity to be selectively shuttled into exosomes. The cultured cells used in our study were immortalized mouse aortic endothelial cells (iMAECs) and RAW 264.7 macrophages. From our results, we observed a significant decrease in miR-33a-5p expression in macrophages treated with exosomes released basolaterally by LPS-challenged iMAECs incubated with LP-pXMoAntimiR33a5p when compared to control macrophages. This decrease in miR-33a-5p expression in the treated macrophages caused ABCA1 upregulation as determined by a significant increase in ABCA1 protein expression in the treated macrophages when compared to the macrophage control group. The increase in ABCA1 protein also simulated ABCA1-dependent cholesterol efflux in treated macrophages-as we observed a significant increase in apoAI-mediated cholesterol efflux-when compared to the control group of macrophages. Based on these findings, strategies that involve combining proinflammatory-targeting lipoparticles and exploitation of endothelial cell-derived exosomes appear to be promising approaches for delivering atheroprotective transgenes to lipid-laden arterial intimal macrophages.

Scavenger receptor-AI targeted theranostic nanoparticles for regression of atherosclerotic plaques via ABCA1 modulation

ATP-binding cassette transporter A1 (ABCA1) plays a crucial role in atherosclerotic formation through mediated cholesterol efflux in macrophage-derived foam cells. In this study, a scavenger receptors AI (SR-AI) targeted theranostic nanoparticles was constructed for atherosclerosis regression via ABCA1 activation in foam cells. ABCA1-upregulator 5242331 and IR780 were encapsulated in PLGA-PEG micelles which were conjugated with SR-AI targeting peptide (PP1) to formulate the nanoparticles (SAU-NPs). Immunostaining revealed that SR-AI was highly expressed both in macrophage foam cells and in atherosclerotic plaque of ApoE^-/- mice. The SAU-NPs have shown more active targeting to plaque lesion with higher stability compared with non-SR-AI targeted nanoparticles. The transformation from macrophage to foam cells was inhibited by SAU-NPs carried 5242331. Cholesterol deposition was effectively reduced in foam cells by SAU-NPs through activating the LXRα-ABCA1/ABCG1/SR-BI pathway. In conclusion, theranostic SAU-NPs which carried ABCA1-upregulator 5242331 exert beneficial effects on atherosclerosis regression via LXRα activation.

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.

Dysregulation of mTOR Signaling after Brain Ischemia

In this review, we provide recent data on the role of mTOR kinase in the brain under physiological conditions and after damage, with a particular focus on cerebral ischemia. We cover the upstream and downstream pathways that regulate the activation state of mTOR complexes. Furthermore, we summarize recent advances in our understanding of mTORC1 and mTORC2 status in ischemia–hypoxia at tissue and cellular levels and analyze the existing evidence related to two types of neural cells, namely glia and neurons. Finally, we discuss the potential use of mTORC1 and mTORC2 as therapeutic targets after stroke.

Nanoparticle-Based Modification of the DNA Methylome: A Therapeutic Tool for Atherosclerosis?

Cardiovascular epigenomics is a relatively young field of research, yet it is providing novel insights into gene regulation in the atherosclerotic arterial wall. That information is already pointing to new avenues for atherosclerosis (AS) prevention and therapy. In parallel, advances in nanoparticle (NP) technology allow effective targeting of drugs and bioactive molecules to the vascular wall. The partnership of NP technology and epigenetics in AS is just beginning and promises to produce novel exciting candidate treatments. Here, we briefly discuss the most relevant recent advances in the two fields. We focus on AS and DNA methylation, as the DNA methylome of that condition is better understood in comparison with the rest of the cardiovascular disease field. In particular, we review the most recent advances in NP-based delivery systems and their use for DNA methylome modification in inflammation. We also address the promises of DNA methyltransferase inhibitors for prevention and therapy. Furthermore, we emphasize the unique challenges in designing therapies that target the cardiovascular epigenome. Lastly, we touch the issue of human exposure to industrial NPs and its impact on the epigenome as a reminder of the undesired effects that any NP-based therapy must avoid to be apt for secondary prevention of AS.