Rapid reduction in plaque inflammation by sonodynamic therapy inpatients with symptomatic femoropopliteal peripheral artery disease:A randomized controlled trial

Arterial Adventitial Vasa Vasorum Density Reflects The Progression Of Unstable Plaques: A Retrospective Clinical Study

OBJECTIVE

Arterial adventitial vasa vasorum (AVV) plays an important role in the occurrence and development of atherosclerotic (AS) disease. AS is a systemic disease, and plaque is not only a local vascular event, but also occurs at multiple sites throughout the vascular bed. Currently, effective anti-AVV therapies are lacking. Therefore, we posed the following scientific questions: "does human carotid adventitial vasa vasorum density reflect plaque neovascularization and intimal-media hyperplasia in carotid?"; and "is it possible to reduce human AVV density by sonodynamic therapy (SDT)?"

METHODS

A retrospective study was conducted on 160 patients with carotid atherosclerosis. Duplex ultrasound scanning (DUS), contrast-enhanced ultrasound (CEUS), coronary angiography, and coronary CT angiography (CTA) were used for diagnosis and screening. Pearson correlation tests and Receiver operating characteristic (ROC) curve were used to analyze the relationships between AVV hyperplasia, vasa vasorum (VV) hyperplasia and the intima-media thickness (IMT). SDT was developed for the treatment of arterial AVV hyperplasia and AS plaques.

RESULTS

The presence of local AVV in carotid unstable plaques correlated with the echogenic properties of the carotid plaque and the extent of plaque progression; Furthermore local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with acute coronary syndrome (ACS) events; Local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with coronary artery stenosis. Notably, SDT reduced local AVV hyperplasia and shrank the plaques in human femoral and carotid atherosclerotic lesions.

CONCLUSIONS

The presence of AVV in human carotid arteries reflects the severity of carotid and coronary artery AS. Further, SDT can reduce the hyperplasia of local AVV in human femoral and carotid plaques.

Sonodynamic therapy for the treatment of atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease of large and medium-sized arteries that leads to ischemic heart disease, stroke, and peripheral vascular disease. Despite the current treatments, mortality and disability still remain high. Sonodynamic therapy (SDT), a non-invasive and localized methodology, has been developed as a promising new treatment for inhibiting atherosclerotic progression and stabilizing plaques. Promising progress has been made through cell and animal assays, as well as clinical trials. For example, the effect of SDT on apoptosis and autophagy of cells in AS, especially macrophages, and the concept of non-lethal SDT has also been proposed. In this review, we summarize the ultrasonic parameters and known sonosensitizers utilized in SDT for AS; we elaborate on SDT's therapeutic effects and mechanisms in terms of macrophages, T lymphocytes, neovascularization, smooth muscle cells, lipid, extracellular matrix and efferocytosis within plaques; additionally, we discuss the safety of SDT. A comprehensive summary of the confirmed effects of SDT on AS is conducted to establish a framework for future researchers.

Macrophage-targeted ultrasound nanobubbles for highly efficient sonodynamic therapy of atherosclerotic plaques by modulating M1-to-M2 polarization

BACKGROUND AND AIMS

Sonodynamic therapy (SDT) is a new approach for the treatment of atherosclerosis (AS), yet the poor targeting ability of sonosensitizers limits its therapeutic efficacy. Herein, we reported a plaque-targeted nanoplatform modified with macrophage type A scavenger receptor (SR-A)-targeted peptide (designated as SR-A-Ce6NB) to augment the efficacy of low-intensity pulsed ultrasound (LIPUS)-mediated SDT of atherosclerotic plaque.

METHODS

SR-A-Ce6NB was fabricated by thin hydration method and biotin-avidin system, and its physicochemical properties, biocompatibility and plaque-targeting ability were investigated. RAW 264.7 cells were used for in vitro experimental studies. Male 6-week-old apolipoprotein E-deficient mice were fed a high-fat diet for 16 weeks to induce aortic atherosclerotic plaques. Plaque-bearing mice were randomly allocated into five groups (n = 6): control group, Ce6 + LIPUS group, Ce6NB + LIPUS group, SR-A-Ce6NB + LIPUS group and atorvastatin group. After treatment in each group, the aortic artery was harvested for Oil red O, H&E, Masson's trichrome staining, immunohistochemical and immunofluorescent staining.

RESULTS

SR-A-Ce6NB with high stability and excellent biocompatibility was successfully fabricated. SR-A-Ce6NB could actively target activated macrophages and selectively accumulate in the plaque. SR-A-Ce6NB could be triggered by LIPUS and had a more potent sonodynamic effect than free Ce6 to potentiate SDT. SR-A-Ce6NB-mediated SDT enhanced the anti-atherogenic effect via modulating M1-to-M2 macrophage polarization and had an earlier onset of action on plaque than the statin-mediated effect. No apparent side effect was observed after intravenous SR-A-Ce6NB injection and LIPUS exposure.

CONCLUSIONS

Macrophage-targeted nanoplatform SR-A-Ce6NB-mediated SDT provides a safe, effective and preferable anti-atherogenic therapy by mediating M1-to-M2 macrophage polarization.

Recent Advances for Dynamic-Based Therapy of Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease, which may lead to high morbidity and mortality. Currently, the clinical treatment strategy for AS is administering drugs and performing surgery. However, advanced therapy strategies are urgently required because of the deficient therapeutic effects of current managements. Increased number of energy conversion-based organic or inorganic materials has been used in cancer and other major disease treatments, bringing hope to patients with the development of nanomedicine and materials. These treatment strategies employ specific nanomaterials with specific own physiochemical properties (external stimuli: light or ultrasound) to promote foam cell apoptosis and cholesterol efflux. Based on the pathological characteristics of vulnerable plaques, energy conversion-based nano-therapy has attracted increasing attention in the field of anti-atherosclerosis. Therefore, this review focuses on recent advances in energy conversion-based treatments. In addition to summarizing the therapeutic effects of various techniques, the regulated pathological processes are highlighted. Finally, the challenges and prospects for further development of dynamic treatment for AS are discussed.

Multi-Modality Imaging of Atheromatous Plaques in Peripheral Arterial Disease: Integrating Molecular and Imaging Markers

Peripheral artery disease (PAD) is a common and debilitating condition characterized by the narrowing of the limb arteries, primarily due to atherosclerosis. Non-invasive multi-modality imaging approaches using computed tomography (CT), magnetic resonance imaging (MRI), and nuclear imaging have emerged as valuable tools for assessing PAD atheromatous plaques and vessel walls. This review provides an overview of these different imaging techniques, their advantages, limitations, and recent advancements. In addition, this review highlights the importance of molecular markers, including those related to inflammation, endothelial dysfunction, and oxidative stress, in PAD pathophysiology. The potential of integrating molecular and imaging markers for an improved understanding of PAD is also discussed. Despite the promise of this integrative approach, there remain several challenges, including technical limitations in imaging modalities and the need for novel molecular marker discovery and validation. Addressing these challenges and embracing future directions in the field will be essential for maximizing the potential of molecular and imaging markers for improving PAD patient outcomes.

Spotlight on porphyrins: Classifications, mechanisms and medical applications

Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are non-invasive treatment methods with obvious inhibitory effect on tumors and have few side effects, which have been widely concerned and explored by researchers. Sensitizer is the main factor in determining the therapeutic effect of PDT and SDT. Porphyrins, a group of organic compounds widespread in nature, can be activated by light or ultrasound and produce reactive oxygen species. Therefore, porphyrins as sensitizers in PDT have been widely explored and investigated for many years. Herein, we summarize the classical porphyrin compounds and their applications and mechanisms in PDT and SDT. The application of porphyrin in clinical diagnosis and imaging is also discussed. In conclusion, porphyrins have good application prospects in disease treatment as an important part of PDT or SDT, and in clinical diagnosis and imaging.

Sonodynamic therapy suppresses matrix collagen degradation in vulnerable atherosclerotic plaque by modulating caspase 3 - PEDF/HIF-1α - MMP-2/MMP-9 signaling in macrophages

BACKGROUND

The rupture of vulnerable atherosclerotic plaque is the main cause of acute ischemic vascular events, and is characterized by pathological degradation of matrix collagen in the fibrous cap. In a previous study, we reported that 5-aminolevulinic acid-mediated sonodynamic therapy suppressed collagen degradation in rabbit plaque. However, the underlying molecular mechanism has yet to be fully elucidated.

METHODS

We applied sinoporphyrin sodium-mediated sonodynamic therapy (DVDMS-SDT) to balloon-denuded rabbit and apolipoprotein E-deficient (ApoE-/-) mouse models to observe collagen content in plaque. Cultured human THP-1 and mouse peritoneal macrophage-derived foam cells were used for in vitro mechanistic studies.

RESULTS

We observed that DVDMS-SDT decreased plaque area and increased the percentages of collagen and smooth muscle cells and reduced the percentage of macrophages in rabbit and ApoE-/- mouse advanced plaques. In vitro, DVDMS-SDT modulated the caspase 3-pigment epithelium-derived factor/hypoxia-inducible factor-1α (PEDF/HIF-1α)-matrix metalloprotease-2/9 (MMP-2/MMP-9) signaling in macrophage foam cells.

CONCLUSIONS

Our findings show that DVDMS-SDT effectively inhibits matrix collagen degradation in advanced atherosclerotic plaque by modulating caspase 3-PEDF/HIF-1α-MMP-2/MMP-9 signaling in macrophage foam cells and therefore represents a suitable and promising clinical regimen to stabilize vulnerable plaques.

Molecular Imaging of Lower Extremity Peripheral Arterial Disease: An Emerging Field in Nuclear Medicine

Peripheral arterial disease (PAD) is an atherosclerotic disorder of non-coronary arteries that is associated with vascular stenosis and/or occlusion. PAD affecting the lower extremities is characterized by a variety of health-related consequences, including lifestyle-limiting intermittent claudication, ulceration of the limbs and/or feet, increased risk for lower extremity amputation, and increased mortality. The diagnosis of lower extremity PAD is typically established by using non-invasive tests such as the ankle-brachial index, toe-brachial index, duplex ultrasound, and/or angiography imaging studies. While these common diagnostic tools provide hemodynamic and anatomical vascular assessments, the potential for non-invasive physiological assessment of the lower extremities has more recently emerged through the use of magnetic resonance- and nuclear medicine-based approaches, which can provide insight into the functional consequences of PAD-related limb ischemia. This perspectives article specifically highlights and discusses the emerging applications of clinical nuclear medicine techniques for molecular imaging investigations in the setting of lower extremity PAD.

Patient-Reported Outcome Measures in Symptomatic, Non-Limb-Threatening Peripheral Artery Disease: A State-of-the-Art Review

Patient-reported outcome measures (PROMs) are health outcomes directly reported by the patient that can be used to measure the effect of disease and treatments on patient perceived well-being. This review summarizes current evidence regarding the validation of PROMs in people with symptomatic, nonlimb-threatening peripheral artery disease. A literature search was conducted to identify studies of symptomatic peripheral artery disease without limb-threatening ischemia that included PROMs and had sample sizes ≥25. PROMs were summarized along a continuum of validation using classical test theory framework and according to whether they fulfilled defined criteria for (1) content validity; (2) psychometric validation; and (3) further validation evidence base expansion. Of 2198 articles identified, 157 (7.1%) met inclusion criteria. Twenty-four PROMs in patients with symptomatic peripheral artery disease were reviewed. Among disease-specific PROMs, 8 of 15 had excellent reliability as measured by a Cronbach alpha ≥0.80. Based on established criteria for PROM responsiveness, 6 of 15 disease-specific PROMs demonstrated excellent sensitivity to change. Of these, the disease-specific peripheral artery questionnaire, vascular quality of life questionnaire, and walking impairment questionnaire met criteria for validation at each stage of the continuum. For generic (nondisease specific) PROMs, the European Quality of Life 5-Dimension and SF-36 had the most extensive evidence of validation. Evidence from this review can inform selection of PROMs aligned with scientific and clinical goals, given the variable degree of validation and potential complementary nature of the measures.

Organic Sonosensitizers for Sonodynamic Therapy: From Small Molecules and Nanoparticles toward Clinical Development

Sonodynamic therapy (SDT) is a novel noninvasive therapeutic modality that combines low-intensity ultrasound and sonosensitizers. Versus photo-mediated therapy, SDT has the advantages of deeper tissue penetration, high accuracy, and less side effects. Sonosensitizers are critical for therapeutic efficacy during SDT and organic sonosensitizers are important because of their clear structure, easy monitoring, evaluation of drug metabolism, and clinical transformation. Notably, nanotechnology can be used in the field of sonosensitizers and SDT to overcome the inherent obstacles and achieve sustainable innovation. This review introduces organic small molecule sonosensitizers, nano organic sonosensitizers, and their clinical translation by providing ideas and references for the design of sonosensitizers and SDT so as to promote its transformation to clinical applications in the future.

Low-Intensity Focused Ultrasound-Responsive Ferrite-Encapsulated Nanoparticles for Atherosclerotic Plaque Neovascularization Theranostics

Pathological angiogenesis is a crucial factor that causes atherosclerotic plaque rupture. Sinoporphyrin sodium-mediated sonodynamic therapy (DVDMS-SDT) induces regression of plaque neovascularization in humans without causing obvious side effects. However, a clinical noninvasive theranostic strategy for atherosclerotic plaque neovascularization is urgently needed. A nanoplatform designed for multimodality imaging-guided SDT in plaque angiogenesis theranostics, termed PFP-HMME@PLGA/MnFe2 O4 -ramucirumab nanoparticles (PHPMR NPs), is fabricated. It encapsulates manganese ferrite (MnFe2 O4 ), hematoporphyrin monomethyl ether (HMME), and perfluoropentane (PFP) stabilized by polylactic acid-glycolic acid (PLGA) shells and is conjugated to an anti-VEGFR-2 antibody. With excellent magnetic resonance imaging (MRI)/photoacoustic/ultrasound imaging ability, the distribution of PHPMR NPs in plaque can be observed in real time. Additionally, they actively accumulate in the mitochondria of rabbit aortic endothelial cells (RAECs), and the PHPMR NP-mediated SDT promotes mitochondrial-caspase apoptosis via the production of reactive oxygen species and inhibits the proliferation, migration, and tubulogenesis of RAECs. On day 3, PHPMR NP-mediated SDT induces apoptosis in neovessel endothelial cells and improves hypoxia in the rabbit advanced plaque. On day 28, PHPMR NP-mediated SDT reduces the density of neovessels, subsequently inhibiting intraplaque hemorrhage and inflammation and eventually stabilizing the plaque. Collectively, PHPMR NP-mediated SDT presents a safe and effective theranostic strategy for inhibiting plaque angiogenesis.

Sonodynamic therapy for gliomas

INTRODUCTION

Glioma remains incurable and a life limiting disease with an urgent need for effective therapies. Sonodynamic therapy (SDT) involves systemic delivery of non-toxic chemical agents (sonosensitizers) that accumulate in tumor cells or environment and are subsequently activated by exposure to low-frequency ultrasound to become cytotoxic agents. Herein, we discuss proposed mechanisms of action of SDT and provide recommendation for future research and clinical applications of SDT for gliomas.

METHODS

Review of literature of SDT in glioma cell cultures and animal models published in Pubmed/MEDLINE before January, 2021.

RESULTS

Different porphyrin and xanthene derivatives have proven to be effective sonosensitizers. Generation of reactive oxygen species and free radicals from water pyrolysis or sonosensitizers, or physical destabilization of cell membrane, have been identified as mechanisms of SDT leading to cell death. Numerous studies across glioma cell lines using various sonosensitizers and ultrasound parameters have documented tumoricidal effects of SDT. Studies in small animal glioma xenograft models have also consistently documented that SDT is associated with improved tumor control and longer survival of animals treated with SDT while avoiding damage of surrounding brain. There are no clinical trials completed to date regarding safety and efficacy of SDT in patients harboring gliomas, but some are beginning.

CONCLUSIONS

Pre-clinical studies cell cultures and animal models indicate that SDT is a promising treatment approach for gliomas. Further studies should define optimal sonication parameters and sonosensitizers for gliomas. Clinical trials of SDT in patients harboring gliomas and other malignant brain tumors are currently underway.

Sonodynamic therapy reduces iron retention of hemorrhagic plaque

Intraplaque hemorrhage (IPH) plays a major role in the aggressive progression of vulnerable plaque, leading to acute cardiovascular events. We previously demonstrated that sonodynamic therapy (SDT) inhibits atherosclerotic plaque progression. In this study, we investigated whether SDT could also be applied to treat more advanced hemorrhagic plaque and addressed the underlying mechanism. SDT decreased atherosclerotic burden, positively altered atherosclerotic lesion composition, and alleviated iron retention in rabbit hemorrhagic plaques. Furthermore, SDT reduced iron retention by stimulating ferroportin 1 (Fpn1) expression in apolipoprotein E (ApoE)-/- mouse plaques with high susceptibility to IPH. Subsequently, SDT inhibited iron-overload-induced foam-cell formation and pro-inflammatory cytokines secretion in vitro. Moreover, SDT reduced levels of the labile iron pool and ferritin expression via the reactive oxygen species (ROS)-nuclear factor erythroid 2-related factor 2 (Nrf2)-FPN1 pathway. SDT exerted therapeutic effects on hemorrhagic plaques and reduced iron retention via the ROS-Nrf2-FPN1 pathway in macrophages, thereby suggesting that it is a potential translational strategy for patients with advanced atherosclerosis in clinical practice.