Ultrasmall superparamagnetic iron oxide nanoparticles coated with fucoidan for molecular MRI of intraluminal thrombus

Nanocurcumin in myocardial infarction therapy: emerging trends and future directions

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Curcumin has been observed to significantly reduce pathological processes associated with MI. Its clinical application is limited due to its low bioavailability, rapid degradation, and poor solubility. Advancements in nanotechnology can be used to enhance its therapeutic potentials in MI. Curcumin nano-formulation enhances its solubility, stability, and bioavailability, allowing more precise delivery to ischemic cardiac tissue. Curcumin nanoparticles have been observed to successfully reduce infarct size, maintain heart function by modulating essential molecular pathways in MI. Its liposomal formulations provide sustained release and higher tissue penetration with improved pharmacokinetics and enhanced therapeutic efficacy. Preclinical studies revealed that nanocurcumin drastically lower oxidative stress indicators, inflammatory cytokines, and cardiac damage. Micelles composed of polymers have demonstrated high biocompatibility and targeting capabilities with increased cardio-protective effects. Research and clinical trials are essential for comprehensive analysis and efficacy of curcumin-based nano-therapeutics in cardiovascular condition and lowering risk of MI.

First-in-human study of 99mTc-labeled fucoidan, a SPECT tracer targeting P-selectin

BACKGROUND

Activation of endothelial cells and platelets in atherothrombosis is characterized by upregulation of P-selectin. As a consequence, P-selectin represents a potential target for molecular imaging to identify thrombosis at an early stage. Fucoidan is a polysaccharide ligand extracted from brown algae with nanomolar affinity for P-selectin. This first-in-human study evaluated in healthy volunteers the safety, whole-body biodistribution, and dosimetry of 99mTc-fucoidan (Good Manufacturing Practices grade). We also investigated whether we could observe binding of 99mTc-fucoidan to human thrombi ex vivo and in vivo. In ten healthy volunteers, conjugate whole-body scans were performed up to 24 h following intravenous injection of 99mTc-fucoidan (370 MBq). Moreover, 99mTc-fucoidan uptake in ex vivo human thrombi (n = 11) was measured by gamma counting. Additionally, three patients with a newly diagnosed deep vein thrombosis (DVT) were subjected to 99mTc-fucoidan SPECT/CT imaging.

RESULTS

99mTc-fucoidan was well tolerated in all participants without any drug-related adverse events. The total-body absorbed dose in males was comparable to females (0.012 ± 0.004 vs. 0.011 ± 0.005 mSv/MBq; p = 0.97). Gamma counting experiments demonstrated binding of tracer to ex vivo human thrombi that was 16% lower after blocking with a natural P-selectin ligand, Sialyl Lewis X. 99mTc-fucoidan demonstrated specific uptake at the thrombus site in one out of three scanned patients with DVT.

CONCLUSIONS

99mTc-Fucoidan has a favorable biodistribution and safety profile. 99mTc-fucoidan exhibited specific binding to human thrombi in both in vivo and ex vivo settings. Nonetheless, the in vivo results do not support further clinical investigation of 99mTc-fucoidan as an imaging modality for DVT. Other clinical implementations of a technetium- 99m-labeled P-selectin tracer should be considered.

TRIAL REGISTRATION

Clinicaltrials,NCT03422055.Registered 01/15/2018. URL: https://clinicaltrials.gov/study/NCT03422055 Landelijk Trial Register, NL7739. Registered 4/2/2019 . https://onderzoekmetmensen.nl/en/trial/26785.

Controlled Drug Release Systems for Cerebrovascular Diseases

This review offers a comprehensive exploration of optimized drug delivery systems tailored for controlled release and their crucial role in addressing cerebrovascular diseases. Through an in‐depth analysis, various controlled release methods, including nanoparticles, liposomes, hydrogels, and other emerging technologies are examined. Highlighting the importance of precise drug targeting, it is delved into the underlying mechanisms of these delivery systems and their potential to improve therapeutic outcomes while minimizing adverse effects. Additionally, the specific applications of these optimized drug delivery systems in treating cerebrovascular disorders such as ischemic stroke, cerebral aneurysms, and intracranial hemorrhage are discussed. By shedding light on the advancements in drug delivery techniques and their implications in cerebrovascular medicine, this review offers valuable insights into the future of therapeutic interventions in neurology.

Potential role of Chinese medicine nanoparticles to treat coronary artery disease

Coronary artery disease (CAD) is a leading cause of death worldwide, while conventional treatments such as percutaneous coronary intervention (PCI) have limitations. This review aims to explore the potential of nanoparticles loaded with Chinese medicine in the treatment of CAD. We conducted a comprehensive literature search to summarize the characteristics of nanovehicle systems, targeting strategies, and administration methods of various nanoparticles containing Chinese medicine for CAD treatment. Nanoparticle-based drug delivery systems, capable of delivering Chinese medicine, offer several advantages, including high targeting efficiency, prolonged half-life, and low systemic toxicity, making them promising for CAD treatment. Overall, nanoparticles containing Chinese medicine present a promising approach for the treatment of CAD.

Application of Nanotechnology in Thrombus Therapy

A thrombus is a blood clot that forms in the lumen of an artery or vein, restricting blood flow and causing clinical symptoms. Thrombosis is associated with many life-threatening cardiovascular diseases. However, current clinical therapeutic technologies still have many problems in targeting, enrichment, penetration, and safety to meet the thrombosis treatment needs. Therefore, researchers devote themselves to developing nanosystems loaded with antithrombotic drugs to address this paradox in recent years. Herein, the existing thrombosis treatment technologies are first reviewed; and then, their advantages and disadvantages are outlined based on a brief discussion of thrombosis's definition and formation mechanism. Furthermore, the need and application cases for introducing nanotechnology are discussed, focusing on thrombus-specific targeted ligand modification technology and microenvironment-triggered responsive drug release technology. Then, nanomaterials that can be used to design antithrombotic nanotherapeutic systems are summarized. Moreover, a variety of drug delivery technologies driven by nanomotors in thrombosis therapy is also introduced. Last of all, a prospective discussion on the future development of nanotechnology for thrombosis therapy is highlighted.

MRI Contrast Agents in Glycobiology

Molecular recognition involving glycoprotein-mediated interactions is ubiquitous in both normal and pathological natural processes. Therefore, visualization of these interactions and the extent of expression of the sugars is a challenge in medical diagnosis, monitoring of therapy, and drug design. Here, we review the literature on the development and validation of probes for magnetic resonance imaging using carbohydrates either as targeting vectors or as a target. Lectins are important targeting vectors for carbohydrate end groups, whereas selectins, the asialoglycoprotein receptor, sialic acid end groups, hyaluronic acid, and glycated serum and hemoglobin are interesting carbohydrate targets.

Fucoidan-based nanomaterial and its multifunctional role for pharmaceutical and biomedical applications

Fucoidans are promising sulfated polysaccharides isolated from marine sources that have piqued the interest of scientists in recent years due to their widespread use as a bioactive substance. Bioactive coatings and films, unsurprisingly, have seized these substances to create novel, culinary, therapeutic, and diagnostic bioactive nanomaterials. The applications of fucoidan and its composite nanomaterials have a wide variety of food as well as pharmacological properties, including anti-oxidative, anti-inflammatory, anti-cancer, anti-thrombic, anti-coagulant, immunoregulatory, and anti-viral properties. Blends of fucoidan with other biopolymers such as chitosan, alginate, curdlan, starch, etc., have shown promising coating and film-forming capabilities. A blending of biopolymers is a recommended approach to improve their anticipated properties. This review focuses on the fundamental knowledge and current development of fucoidan, fucoidan-based composite material for bioactive coatings and films, and their biological properties. In this article, fucoidan-based edible bioactive coatings and films expressed excellent mechanical strength that can prolong the shelf-life of food products and maintain their biodegradability. Additionally, these coatings and films showed numerous applications in the biomedical field and contribute to the economy. We hope this review can deliver the theoretical basis for the development of fucoidan-based bioactive material and films.

Prodigious therapeutic effects of combining mesenchymal stem cells with magnetic nanoparticles

Mesenchymal stem cells (MSCs) have gained wide-ranging reputation in the medical research community due to their promising regenerative abilities. MSCs can be isolated from various resources mostly bone marrow, Adipose tissues and Umbilical cord. Huge advances have been achieved in comprehending the possible mechanisms underlying the therapeutic functions of MSCs. Despite the proven role of MSCs in repairing and healing of many disease modalities, many hurdles hinder the transferring of these cells in the clinical settings. Among the most reported problems encountering MSCs therapy in vivo are loss of tracking signal post-transplantation, insufficient migration, homing and engraftment post-infusion, and undesirable differentiation at the site of injury. Magnetic nano particles (MNPs) have been used widely for various biomedical applications. MNPs have a metallic core stabilized by an outer coating material and their ma gnetic properties can be modulated by an external magnetic field. These magnetic properties of MNPs were found to enhance the quality of diagnostic imaging procedures and can be used to create a carrying system for targeted delivery of therapeutic substances mainly drug, genes and stem cells. Several studies highlighted the advantageous outcomes of combining MSCs with MNPs in potentiating their tracking, monitoring, homing, engraftment and differentiation. In this review, we will discuss the role of MNPs in promoting the therapeutic profile of MSCs which may improve the success rate of MSCs transplantation and solve many challenges that delay their clinical applicability.

Fucoidan-based nanoparticles: Preparations and applications

Nanoparticle-based therapy has gained much attention in the pharmaceutical industry. Fucoidan is a sulfated polysaccharide naturally derived from marine brown algae and is widely used for medical applications. We explore preparation of fucoidan-based nanoparticles and their biomedical applications in the current review. The fucoidan-based nanoparticles have been synthesized using microwave, emulsion, solvent evaporation, green synthesis, polyelectrolyte self-assembly, precipitation, and ultrasonication methods. The synthesized nanoparticles have particle sizes ranging from 100 to 400 nm. Therefore, fucoidan-based nanoparticles have a variety of potential therapeutic applications, including drug delivery, cancer therapies, tissue engineering, antimicrobial applications, magnetic resonance imaging contrast, and atherothrombosis imaging. For example, fucoidan nanoparticles have been used to deliver curcumin, dextran, gentamicin, epigallocatechin gallate, and cisplatin for cancer therapies. Furthermore, fucoidan nanoparticles coupled with metal nanoparticles have been used to target and recognize clinical conditions for diagnostic purposes. Hence, fucoidan-based nanoparticles have been helpful for biomedical applications.

Theranostic Nanomedicines for the Treatment of Cardiovascular and Related Diseases: Current Strategies and Future Perspectives

Cardiovascular and related diseases (CVRDs) are among the most prevalent chronic diseases in the 21st century, with a high mortality rate. This review summarizes the various nanomedicines for diagnostic and therapeutic applications in CVRDs, including nanomedicine for angina pectoris, myocarditis, myocardial infarction, pericardial disorder, thrombosis, atherosclerosis, hyperlipidemia, hypertension, pulmonary arterial hypertension and stroke. Theranostic nanomedicines can prolong systemic circulation, escape from the host defense system, and deliver theranostic agents to the targeted site for imaging and therapy at a cellular and molecular level. Presently, discrete non-invasive and non-surgical theranostic methodologies are such an advancement modality capable of targeted diagnosis and therapy and have better efficacy with fewer side effects than conventional medicine. Additionally, we have presented the recent updates on nanomedicine in clinical trials, targeted nanomedicine and its translational challenges for CVRDs. Theranostic nanomedicine acts as a bridge towards CVRDs amelioration and its management.

Nanocarrier-Based Management of Venous and Arterial Thrombosis

Cardiovascular diseases represent the leading cause of mortality worldwide, with recent epidemiological studies revealing an increasing trend of prevalence and incidence globally. Among cardiovascular disorders, both arterial and venous thrombosis and particularly their acute life-threating complications such as ischemic stroke, acute myocardial infarction, deep venous thrombosis and pulmonary embolism are responsible for more than 25% of all deaths worldwide. The modern approach following progresses in anticoagulant, thrombolytic and antiaggregant therapies has significantly improved the prognoses of these conditions in the last past decades. However, several challenges still remain such as achieving the optimal drug concentration at the injured site, reducing the shortcomings of drug resistance and the incidence of life-threatening hemorrhages. Nanomedicine is a well-known field of medicine in which atomic and molecular structures ranging between 0.1–100 nm are used in various domains due to their specific mechanical, electrical, thermal and magnetic properties. Recent experimental and clinical evidence have shown that nanotechnology could be a safe, effective and an appealing approach for various non-cardiovascular and cardiovascular diseases such as thromboembolic conditions. In this review, we have described the most promising nanotechnology-based approaches not only for the diagnosis, but also for the treatment of vascular thrombotic diseases.

Coagulation System Activation for Targeting of COVID-19: Insights into Anticoagulants, Vaccine-Loaded Nanoparticles, and Hypercoagulability in COVID-19 Vaccines

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, is currently developing into a rapidly disseminating and an overwhelming worldwide pandemic. In severe COVID-19 cases, hypercoagulability and inflammation are two crucial complications responsible for poor prognosis and mortality. In addition, coagulation system activation and inflammation overlap and produce life-threatening complications, including coagulopathy and cytokine storm, which are associated with overproduction of cytokines and activation of the immune system; they might be a lead cause of organ damage. However, patients with severe COVID-19 who received anticoagulant therapy had lower mortality, especially with elevated D-dimer or fibrin degradation products (FDP). In this regard, the discovery of natural products with anticoagulant potential may help mitigate the numerous side effects of the available synthetic drugs. This review sheds light on blood coagulation and its impact on the complication associated with COVID-19. Furthermore, the sources of natural anticoagulants, the role of nanoparticle formulation in this outbreak, and the prevalence of thrombosis with thrombocytopenia syndrome (TTS) after COVID-19 vaccines are also reviewed. These combined data provide many research ideas related to the possibility of using these anticoagulant agents as a treatment to relieve acute symptoms of COVID-19 infection.

Bioactive Compounds and Nanodelivery Perspectives for Treatment of Cardiovascular Diseases

Bioactive compounds are comprised of small quantities of extra nutritional constituents providing both health benefits and enhanced nutritional value, based on their ability to modulate one or more metabolic processes. Plant-based diets are being thoroughly researched for their cardiovascular properties and effectiveness against cancer. Flavonoids, phytoestrogens, phenolic compounds, and carotenoids are some of the bioactive compounds that aim to work in prevention and treating the cardiovascular disease in a systemic manner, including hypertension, atherosclerosis, and heart failure. Their antioxidant and anti-inflammatory properties are the most important characteristics that make them favorable candidates for CVDs treatment. However, their low water solubility and stability results in low bioavailability, limited accessibility, and poor absorption. The oral delivery of bioactive compounds is constrained due to physiological barriers such as the pH, mucus layer, gastrointestinal enzymes, epithelium, etc. The present review aims to revise the main bioactive compounds with a significant role in CVDs in terms of preventive, diagnostic, and treatment measures. The advantages of nanoformulations and novel multifunctional nanomaterials development are described in order to overcome multiple obstacles, including the physiological ones, by summarizing the most recent preclinical data and clinical trials reported in the literature. Nanotechnologies will open a new window in the area of CVDs with the opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues.

Theranostic nanobubbles towards smart nanomedicines

Targeted therapy and early accurate detection of malignant lesions are essential for the effectiveness of treatment and prognosis in cancer patients. The development of gaseous system as a versatile platform for the fabricated nanobubbles, has attracted much interest in improving the efficacy of ultrasound therapeutic, diagnostic, and theranostic platforms. Nano-sized bubble, as an ultrasound contrast agent, with spherical gas-filled structures exhibited contrast enhancement capability due to their inherent EPR effect. Additionally, nanobubbles exhibited good stability with extended retention time in the blood stream. The current review summarized various nanobubbles and discussed about the crucial parameters affecting the stability of ultrafine bubbles. Furthermore, therapeutic and theranostic gaseous systems for fighting against cancer were described.

Activated Platelet-Homing Nanoplatform for Targeting Magnetic Resonance Imaging of Aneurysm-Related Thrombus in Rabbits

Thrombosis is closely related to the instability of intracranial aneurysm (IA), whose rupture is associated with high morbidity and mortality. It is difficult to detect an IA-related thrombus because traditional magnetic resonance imaging (MRI) and even contrast-enhanced MRI cannot clearly distinguish a thrombus from the surrounding tissues. Herein, a nanoplatform [(MFe₂O₄-ZnDPA nanoparticles (NPs)], consisting of Zn_0.4Co_0.6Fe₂O₄@Zn_0.4Mn_0.6Fe₂O₄ NPs for imaging and Zn(II)-bis(dipicolylamine) (ZnDPA) for thrombus targeting, is constructed to target an experimental aneurysm-related thrombus in rabbits via MRI. In vitro experiments including platelet safety evaluation primarily prove that MFe₂O₄-ZnDPA NPs with a high MRI transverse relaxation time (T₂) have good biocompatibility. MFe₂O₄-ZnDPA NPs could target a thrombus via the special interaction between ZnDPA and phosphatidylserine of activated platelets in the thrombus through MRI and Fe quantification assays. Moreover, after MFe₂O₄-ZnDPA NPs are injected into the ear vein of common carotid artery aneurysm model rabbits, MRI shows that MFe₂O₄-ZnDPA NPs could accumulate in the aneurysm-related thrombus from 0 to 15 min after injection and decrease in the next 45 min. Meanwhile, MFe₂O₄-ZnDPA NPs could decrease the MRI T₂ signal of the aneurysm-related thrombus to enhance the outline of the aneurysm. This study demonstrates that a nanoplatform can enhance the detection of an aneurysm-related thrombus as well as aneurysm itself to assist further treatment of IA.

Fucoidan for cardiovascular application and the factors mediating its activities

Fucoidan is a sulfated polysaccharide with various bioactivities. The application of fucoidan in cancer treatment, wound healing, and food industry has been extensively studied. However, the therapeutic value of fucoidan in cardiovascular diseases has been less explored. Increasing number of investigations in the past years have demonstrated the effects of fucoidan on cardiovascular system. In this review, we will focus on the bioactivities related to cardiovascular applications, for example, the modulation functions of fucoidan on coagulation system, inflammation, and vascular cells. Factors mediating those activities will be discussed in detail. Current therapeutic strategies and future opportunities and challenges will be provided to inspire and guide further research.

The choice of targets and ligands for site-specific delivery of nanomedicine to atherosclerosis

As nanotechnologies advance into clinical medicine, novel methods for applying nanomedicine to cardiovascular diseases are emerging. Extensive research has been undertaken to unlock the complex pathogenesis of atherosclerosis. However, this complexity presents challenges to develop effective imaging and therapeutic modalities for early diagnosis and acute intervention. The choice of ligand-receptor system vastly influences the effectiveness of nanomedicine. This review collates current ligand-receptor systems used in targeting functionalized nanoparticles for diagnosis and treatment of atherosclerosis. Our focus is on the binding affinity and selectivity of ligand-receptor systems, as well as the relative abundance of targets throughout the development and progression of atherosclerosis. Antibody-based targeting systems are currently the most commonly researched due to their high binding affinities when compared with other ligands, such as antibody fragments, peptides, and other small molecules. However, antibodies tend to be immunogenic due to their size. Engineering antibody fragments can address this issue but will compromise their binding affinity. Peptides are promising ligands due to their synthetic flexibility and low production costs. Alongside the aforementioned binding affinity of ligands, the choice of target and its abundance throughout distinct stages of atherosclerosis and thrombosis is relevant to the intended purpose of the nanomedicine. Further studies to investigate the components of atherosclerotic plaques are required as their cellular and molecular profile shifts over time.

Molecular Imaging of Arterial and Venous Thrombosis

Thrombosis contributes to one in four deaths worldwide and is the cause of a large proportion of mortality and morbidity. A reliable and rapid diagnosis of thrombosis will allow for immediate therapy, thereby providing significant benefits to patients. Molecular imaging is a fast-growing and captivating area of research, in both preclinical and clinical applications. Major advances have been achieved by improvements in three central areas of molecular imaging: 1) Better markers for diseases, with increased sensitivity and selectivity; 2) Optimised contrast agents with improved signal to noise ratio; 3) Progress in scanner technologies with higher sensitivity and resolution. Clinically available imaging modalities used for molecular imaging include, magnetic resonance imaging (MRI), X-ray computed tomography (CT), ultrasound, as well as nuclear imaging, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT). In the preclinical imaging field, optical (fluorescence and bioluminescent) molecular imaging has provided new mechanistic insights in the pathology of thromboembolic diseases. Overall, the advances in molecular imaging, driven by the collaboration of various scientific disciplines, have substantially contributed to an improved understanding of thrombotic disease, and raises the exciting prospect of earlier diagnosis and individualised therapy for cardiovascular diseases. As such, these advances hold significant promise to be translated to clinical practice and ultimately to reduce mortality and morbidity in patients with thromboembolic diseases.

Polymer-Based Materials and Their Applications in Image-Guided Cancer Therapy

BACKGROUND

Advances in nanotechnology have enabled the combination of disease diagnosis and therapy into a single nano package that has tremendous potential for the development of new theranostic strategies. The variety of polymer-based materials has grown exponentially over the past several decades. Such materials have great potential as carriers in disease detection imaging and image monitoring and in systems for the precise delivery of drugs to specific target sites.

OBJECTIVE

In the present article, we review recent key developments in the synthesis of polymer-based materials for various medical applications and their clinical trials.

CONCLUSION

There is a growing range of multi-faceted, polymer-based materials with various functions. These functions include carriers for image contrast agents, drug delivery systems, and real-time image-guided systems for noninvasive or minimally invasive therapeutic procedures for cancer therapy.

Imaging Constructs: The Rise of Iron Oxide Nanoparticles

Over the last decade, an important challenge in nanomedicine imaging has been the work to design multifunctional agents that can be detected by single and/or multimodal techniques. Among the broad spectrum of nanoscale materials being investigated for imaging use, iron oxide nanoparticles have gained significant attention due to their intrinsic magnetic properties, low toxicity, large magnetic moments, superparamagnetic behaviour and large surface area-the latter being a particular advantage in its conjunction with specific moieties, dye molecules, and imaging probes. Tracers-based nanoparticles are promising candidates, since they combine synergistic advantages for non-invasive, highly sensitive, high-resolution, and quantitative imaging on different modalities. This study represents an overview of current advancements in magnetic materials with clinical potential that will hopefully provide an effective system for diagnosis in the near future. Further exploration is still needed to reveal their potential as promising candidates from simple functionalization of metal oxide nanomaterials up to medical imaging.

Platelets in Multiple Sclerosis: Early and Central Mediators of Inflammation and Neurodegeneration and Attractive Targets for Molecular Imaging and Site-Directed Therapy

Platelets are clearly central to thrombosis and hemostasis. In addition, more recently, evidence has emerged for non-hemostatic roles of platelets including inflammatory and immune reactions/responses. Platelets express immunologically relevant ligands and receptors, demonstrate adhesive interactions with endothelial cells, monocytes and neutrophils, and toll-like receptor (TLR) mediated responses. These properties make platelets central to innate and adaptive immunity and potential candidate key mediators of autoimmune disorders. Multiple sclerosis (MS) is the most common chronic autoimmune central nervous system (CNS) disease. An association between platelets and MS was first indicated by the increased adhesion of platelets to endothelial cells. This was followed by reports identifying structural and functional changes of platelets, their chronic activation in the peripheral blood of MS patients, platelet presence in MS lesions and the more recent revelation that these structural and functional abnormalities are associated with all MS forms and stages. Investigations based on the murine experimental autoimmune encephalomyelitis (EAE) MS model first revealed a contribution to EAE pathogenesis by exacerbation of CNS inflammation and an early role for platelets in EAE development via platelet-neuron and platelet-astrocyte associations, through sialated gangliosides in lipid rafts. Our own studies refined and extended these findings by identifying the critical timing of platelet accumulation in pre-clinical EAE and establishing an initiating and central rather than merely exacerbating role for platelets in disease development. Furthermore, we demonstrated platelet-neuron associations in EAE, coincident with behavioral changes, but preceding the earliest detectable autoreactive T cell accumulation. In combination, these findings establish a new paradigm by asserting that platelets play a neurodegenerative as well as a neuroinflammatory role in MS and therefore, that these two pathological processes are causally linked. This review will discuss the implications of these findings for our understanding of MS, for future applications for imaging toward early detection of MS, and for novel strategies for platelet-targeted treatment of MS.

Targeted Molecular Imaging of Cardiovascular Diseases by Iron Oxide Nanoparticles

Cardiovascular disease is one of the major contributors to global disease burden. Atherosclerosis is an inflammatory process that involves the accumulation of lipids and fibrous elements in the large arteries, forming an atherosclerotic plaque. Rupture of unstable plaques leads to thrombosis that triggers life-threatening complications such as myocardial infarction. Current diagnostic methods are invasive as they require insertion of a catheter into the coronary artery. Molecular imaging techniques, such as magnetic resonance imaging, have been developed to image atherosclerotic plaques and thrombosis due to its high spatial resolution and safety. The sensitivity of magnetic resonance imaging can be improved with contrast agents, such as iron oxide nanoparticles. This review presents the most recent advances in atherosclerosis, thrombosis, and myocardial infarction molecular imaging using iron oxide-based nanoparticles. While some studies have shown their effectiveness, many are yet to undertake comprehensive testing of biocompatibility. There are still potential hazards to address and complications to diagnosis, therefore strategies for overcoming these challenges are required.

COVID-19: Nanomedicine Uncovers Blood-Clot Mystery

Further complications associated with infection by severe acute respiratory syndrome coronavirus 2 (a.k.a. SARS-CoV-2) continue to be reported. Very recent findings reveal that 20-30% of patients at high risk of mortality from COVID-19 infection experience blood clotting that leads to stroke and sudden death. Timely assessment of the severity of blood clotting will be of enormous help to clinicians in determining the right blood-thinning medications to prevent stroke or other life-threatening consequences. Therefore, rapid identification of blood-clotting-related proteins in the plasma of COVID-19 patients would save many lives. Several nanotechnology-based approaches are being developed to diagnose patients at high risk of death due to complications from COVID-19 infections, including blood clots. This Perspective outlines (i) the significant potential of nanomedicine in assessing the risk of blood clotting and its severity in SARS-CoV-2 infected patients and (ii) its synergistic roles with advanced mass-spectrometry-based proteomics approaches in identifying the important protein patterns that are involved in the occurrence and progression of this disease. The combination of such powerful tools might help us understand the clotting phenomenon and pave the way for development of new diagnostics and therapeutics in the fight against COVID-19.

MRI tracing of ultrasmall superparamagnetic iron oxide nanoparticle‑labeled endothelial progenitor cells for repairing atherosclerotic vessels in rabbits

Endothelial progenitor cells (EPCs) have been discovered to be relevant to the prognosis of cardiovascular diseases. Previous research has demonstrated that EPCs serve vital roles in the occurrence and development of atherosclerosis. Significant improvements have been made in MRI technology and in the experimental use of EPCs for therapeutic angiogenesis and vascular repair. Nevertheless, the migratory, adhesive, proliferative and angiogenic properties of EPCs remain unknown. The aims of the present study were to investigate the potential of using non-invasive monitoring with ultrasmall superparamagnetic iron oxide nanoparticle (USPION)-labeled endothelial progenitor cells (EPCs) after transplantation, and to assess the treatment outcomes in an atherosclerotic rabbit model. EPCs derived from rabbit peripheral blood samples were labeled with USPION-poly-l-lysine (USPION-PLL). The morphology, proliferation, adhesive ability and labeling efficiency of the EPCs were determined by optical and electron microscopy. Moreover, biological activity was assessed by flow cytometry. In addition, T2-weighted image fast spin-echo MRI was used to detect cell labeling. USPION content in the labeled EPCs was determined by Prussian blue staining and scanning electron microscopy. Rabbit atherosclerosis model was established using a high-fat diet. USPION-labeled EPCs were transplanted into rabbits, and in vivo MRI was performed 1 and 7 days after transplantation. It was found that EPCs cultured on Matrigel formed capillary-like structures, and expressed the surface markers CD133, CD31, CD34 and vascular endothelial growth factor receptor 2 (VEGFR2). The optimal USPION concentration was 32 µg/ml, as determined by adhesion and proliferation assays. It was identified that USPION-PLL nanoparticles were 10–20 nm in diameter. Histopathological analysis results indicated that 1 day after transplantation of the labeled EPCs, blue-stained granules were observed in the intima of vascular lesions in rabbit models after Prussian blue staining. Therefore, the present results suggest that USPION-labeled EPCs may play a role in repairing endothelial injury and preventing atherosclerosis in vivo.

Curcumin, a Multifaceted Hormetic Agent, Mediates an Intricate Crosstalk between Mitochondrial Turnover, Autophagy, and Apoptosis

Curcumin has extensive therapeutic potential because of its antioxidant, anti-inflammatory, and antiproliferative properties. Multiple preclinical studies in vitro and in vivo have proven curcumin to be effective against various cancers. These potent effects are driven by curcumin's ability to induce G2/M cell cycle arrest, induce autophagy, activate apoptosis, disrupt molecular signaling, inhibit invasion and metastasis, and increase the efficacy of current chemotherapeutics. Here, we focus on the hormetic behavior of curcumin. Frequently, low doses of natural chemical products activate an adaptive stress response, whereas high doses activate acute responses like autophagy and cell death. This phenomenon is often referred to as hormesis. Curcumin causes cell death and primarily initiates an autophagic step (mitophagy). At higher doses, cells undergo mitochondrial destabilization due to calcium release from the endoplasmic reticulum, and die. Herein, we address the complex crosstalk that involves mitochondrial biogenesis, mitochondrial destabilization accompanied by mitophagy, and cell death.

In vitro Biological Tests as the First Tools To Validate Magnetic Nanotheranostics for Colorectal Cancer Models

Colorectal cancer (CRC) remains a leading cause of cancer death. Nanotechnology has focused on reaching more effective treatments. In this concern, magnetic nanoparticles (MNPs) have been studied for a wide range of biomedical applications related to CRC, such as diagnostic imaging, drug delivery and thermal therapy. However, limited research is currently found in the open literature that refers to nanosystems combining all these mentioned areas (theranostics). When developing nanosystems intended as theranostics applied to CRC, possible variations between patients must be considered. Therefore, multiple in vitro assays are required as guidance for future preclinical and clinical trials. The objective of this contribution is to evaluate the available and recent literature regarding the interactions of MNP and CRC models, aiming to critically analyze the information given by the commonly used assays and evaluate the data provided by each one with a view to implementing this novel technology in CRC diagnostics and therapy.

Emerging nanotherapeutics for antithrombotic treatment

Thrombus causes insufficient blood flow and ischemia damages to brain and heart, leading to life-threatening cardio-cerebrovascular diseases. Development of efficient antithrombotic strategies has long been a high priority, owing to the high morbidity and mortality of thrombotic diseases. With the rapid development of biomedical nanotechnology in diagnosis and treatment of thrombotic disorder, remarkable progresses have been made in antithrombotic nanomedicines in recent years. Herein, we outline the recent advances in this field at the intersection of thrombus theranostics and biomedical nanotechnology. First, thrombus diagnosis techniques based on biomedical nanotechnology are presented. Then, emerging antithrombotic nanotherapeutics are overviewed, including thrombus-targeting strategies, thrombus stimuli-responsive nanosystems and phase transition-driven nanotherapeutics. Furthermore, multifunctional nanosystems for combination theranostics of thrombotic diseases are discussed. Finally, the design considerations, advantages and challenges of these biomedical nanotechnology-driven therapeutics in clinical translation are highlighted.

Nanoparticle-Mediated Drug Delivery for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the foremost causes of high morbidity and mortality globally. Preventive, diagnostic, and treatment measures available for CVDs are not very useful, which demands promising alternative methods. Nanoscience and nanotechnology open a new window in the area of CVDs with an opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues. The application of nanoparticles and nanocarriers in the area of cardiology has gathered much attention due to the properties such as passive and active targeting to the cardiac tissues, improved target specificity, and sensitivity. It has reported that more than 50% of CVDs can be treated effectively through the use of nanotechnology. The main goal of this review is to explore the recent advancements in nanoparticle-based cardiovascular drug carriers. This review also summarizes the difficulties associated with the conventional treatment modalities in comparison to the nanomedicine for CVDs.

Gd(DOTA)-grafted submicronic polysaccharide-based particles functionalized with fucoidan as potential MR contrast agent able to target human activated platelets

Early detection of thrombotic events remains a big medical challenge. Dextran-based submicronic particles bearing Gd(DOTA) groups and functionalized with fucoidan have been produced via a simple and green water-in-oil emulsification/co-crosslinking process. Their capacity to bind to human activated platelets was evidenced in vitro as well as their cytocompatibility with human endothelial cells. The presence of Gd(DOTA) moieties was confirmed by elemental analysis and total reflection X-ray fluorescence (TRXF) spectrometry. Detailed characterization of particles was performed in terms of size distribution, morphology, and relaxation rates. In particular, longitudinal and transversal proton relaxivities were respectively 1.7 and 5.0 times higher than those of DOTAREM. This study highlights their potential as an MRI diagnostic platform for atherothrombosis.

Magnetic Nanoparticles as MRI Contrast Agents

Iron oxide nanoparticles (IONPs) have emerged as a promising alternative to conventional contrast agents (CAs) for magnetic resonance imaging (MRI). They have been extensively investigated as CAs due to their high biocompatibility and excellent magnetic properties. Furthermore, the ease of functionalization of their surfaces with different types of ligands (antibodies, peptides, sugars, etc.) opens up the possibility of carrying out molecular MRI. Thus, IONPs functionalized with epithelial growth factor receptor antibodies, short peptides, like RGD, or aptamers, among others, have been proposed for the diagnosis of various types of cancer, including breast, stomach, colon, kidney, liver or brain cancer. In addition to cancer diagnosis, different types of IONPs have been developed for other applications, such as the detection of brain inflammation or the early diagnosis of thrombosis. This review addresses key aspects in the development of IONPs for MRI applications, namely, synthesis of the inorganic core, functionalization processes to make IONPs biocompatible and also to target them to specific tissues or cells, and finally in vivo studies in animal models, with special emphasis on tumor models.

Nano-Medicine for Thrombosis: A Precise Diagnosis and Treatment Strategy

Thrombosis is a global health issue and one of the leading factors of death. However, its diagnosis has been limited to the late stages, and its therapeutic window is too narrow to provide reasonable and effective treatment. In addition, clinical thrombolytics suffer from a short half-life, allergic reactions, inactivation, and unwanted tissue hemorrhage. Nano-medicines have gained extensive attention in diagnosis, drug delivery, and photo/sound/magnetic-theranostics due to their convertible properties. Furthermore, diagnosis and treatment of thrombosis using nano-medicines have also been widely studied. This review summarizes the recent advances in this area, which revealed six types of nanoparticle approaches: (1) in vitro diagnostic kits using "synthetic biomarkers"; (2) in vivo imaging using nano-contrast agents; (3) targeted drug delivery systems using artificial nanoparticles; (4) microenvironment responsive drug delivery systems; (5) drug delivery systems using biological nanostructures; and (6) treatments with external irradiation. The investigations of nano-medicines are believed to be of great significance, and some of the advanced drug delivery systems show potential applications in clinical theranotics.

The effect of size and surface ligands of iron oxide nanoparticles on blood compatibility

Superparamagnetic iron oxide nanoparticles (SPIONs) have been widely used and have attracted increased attention for their unique physicochemical properties, especially in biomedical sciences as contrast agents following intravenous administration. However, only few studies have systematically reported the blood compatibility of iron oxide nanoparticles with different physicochemical properties such as different sizes and surface ligands. Therefore, we selected three widely used organic ligands (polyacrylic acid, hyaluronic acid, and chitosan) with modified SPIONs at the same size of 5-6 nm, and polyacrylic acid-modified SPIONs with different sizes (5, 10, and 30 nm) at different concentrations to evaluate their haemocompatibility. Our results revealed that SPIONs modified with polyacrylic acid demonstrated size-dependent destruction of red blood cells and complement activation. Interestingly, 5 nm SPIONs prolonged blood clotting time as compared with 10 nm and 30 nm SPIONs in vitro. Compared with polyacrylic acid-modified SPIONs, hyaluronic acid- and chitosan-modified SPIONs least affected red blood cells, platelets, coagulation, and complement activation. Hence, hyaluronic acid- and chitosan-coated SPIONs are more suitable for nanomedicine applications than polyacrylic acid-coated SPIONs. Furthermore, the interaction between SPIONs and blood components strongly correlated with the administered concentration of nanoparticles. These results will provide some experimental information for safe-by-design SPIONs.

The Potential of Fucose-Containing Sulfated Polysaccharides As Scaffolds for Biomedical Applications

Marine environments have a high quantity and diversity of sulfated polysaccharides. In coastal regions brown algae are the most abundant biomass producers and their cell walls have fucosecontaining sulfated polysaccharides (FCSP), known as fucans and/or fucoidans. These sulfated compounds have been widely researched for their biomedical properties, namely the immunomodulatory, haemostasis, pathogen inhibition, anti-inflammatory capacity, and antitumoral. These activities are probably due to their ability to mimic the carbohydrate moieties of mammalian glycosaminoglycans. Therefore, the FCSP are interesting compounds for application in health-related subjects, mainly for developing scaffolds for delivery systems or tissue regeneration. FCSP showed potential for these applications also due to their ability to form stable 3D structures with other polymers able to entrap therapeutic agents or cell and growth factors, besides their biocompatibility and biodegradability. However, for the clinical use of these biopolymers well-defined reproducible molecules are required in order to accurately establish relationships between structural features and human health applications.

From design to the clinic: practical guidelines for translating cardiovascular nanomedicine

Cardiovascular diseases (CVD) account for nearly half of all deaths in Europe and almost 30% of global deaths. Despite the improved clinical management, cardiovascular mortality is predicted to rise in the next decades due to the increasing impact of aging, obesity, and diabetes. The goal of emerging cardiovascular nanomedicine is to reduce the burden of CVD using nanoscale medical products and devices. However, the development of novel multicomponent nano-sized products poses multiple technical, ethical, and regulatory challenges, which often obstruct their road to successful approval and use in clinical practice. This review discusses the rational design of nanoparticles, including safety considerations and regulatory issues, and highlights the steps needed to achieve efficient clinical translation of promising nanomedicinal products for cardiovascular applications.

Targeting P-Selectin Adhesion Molecule in Molecular Imaging: P-Selectin Expression as a Valuable Imaging Biomarker of Inflammation in Cardiovascular Disease

P-selectin is an adhesion molecule translocated to the surface of endothelial cells and platelets under inflammatory stimuli, and its potential as a biomarker in inflammatory conditions has driven preclinical studies to investigate its application for molecular imaging of inflammation. Clinical imaging of P-selectin expression for disease characterization could have an important role in stratifying patients and determining treatment strategies. The objective of this review is to outline the role of P-selectin in cardiovascular inflammatory conditions and its translation as an early inflammatory biomarker for several molecular imaging modalities for diagnostic purposes and therapeutic planning.

Nanotherapies for Treatment of Cardiovascular Disease: A Case for Antioxidant Targeted Delivery

Purpose of Review

Cardiovascular disease (CVD) involves a broad range of clinical manifestations resulting from a dysfunctional vascular system. Overproduction of reactive oxygen and nitrogen species are causally implicated in the severity of vascular dysfunction and CVD. Antioxidant therapy is an attractive avenue for treatment of CVD associated pathologies. Implementation of targeted nano-antioxidant therapies has the potential to overcome hurdles associated with systemic delivery of antioxidants. This review examines the currently available options for nanotherapeutic targeting CVD, and explores successful studies showcasing targeted nano-antioxidant therapy.

Recent Findings

Active targeting strategies in the context of CVD heavily focus on immunotargeting to inflammatory markers like cell adhesion molecules, or to exposed extracellular matrix components. Targeted antioxidant nanotherapies have found success in pre-clinical studies.

Summary

This review underscores the potential of targeted nanocarriers as means of finding success translating antioxidant therapies to the clinic, all with a focus on CVD.

Core-Shell Polymer-Based Nanoparticles Deliver miR-155-5p to Endothelial Cells

Heart failure occurs in over 30% of the worldwide population and most commonly originates from cardiovascular diseases such as myocardial infarction. microRNAs (miRNAs) target and silence specific mRNAs, thereby regulating gene expression. Because the endogenous miR-155-5p has been ascribed to vasculoprotection, loading it onto positively charged, core-shell poly(isobutylcyanoacrylate) (PIBCA)-polysaccharide nanoparticles (NPs) was attempted. NPs showed a decrease (p < 0.0001) in surface electrical charge (ζ potential), with negligible changes in size or shape when loaded with the anionic miR-155-5p. Presence of miR-155-5p in loaded NPs was further quantified. Cytocompatibility up to 100 μg/mL of NPs for 2 days with human coronary artery endothelial cells (hCAECs) was documented. NPs were able to enter hCAECs and were localized in the endoplasmic reticulum (ER). Expression of miR-155-5p was increased within the cells by 75-fold after 4 hours of incubation (p < 0.05) and was still noticeable at day 2. Differences between loaded NP-cultured cells and free miRNA, at days 1 (p < 0.05) and 2 (p < 0.001) suggest the ability of prolonged load release in physiological conditions. Expression of miR-155-5p downstream target BACH1 was decreased in the cells by 4-fold after 1 day of incubation (p < 0.05). This study is a first proof of concept that miR-155-5p can be loaded onto NPs and remain intact and biologically active in endothelial cells (ECs). These nanosystems could potentially increase an endogenous cytoprotective response and decrease damage within infarcted hearts.

Molecular Imaging of the Heart

Multimodality cardiovascular imaging is routinely used to assess cardiac function, structure, and physiological parameters to facilitate the diagnosis, characterization, and phenotyping of numerous cardiovascular diseases (CVD), as well as allows for risk stratification and guidance in medical therapy decision-making. Although useful, these imaging strategies are unable to assess the underlying cellular and molecular processes that modulate pathophysiological changes. Over the last decade, there have been great advancements in imaging instrumentation and technology that have been paralleled by breakthroughs in probe development and image analysis. These advancements have been merged with discoveries in cellular/molecular cardiovascular biology to burgeon the field of cardiovascular molecular imaging. Cardiovascular molecular imaging aims to noninvasively detect and characterize underlying disease processes to facilitate early diagnosis, improve prognostication, and guide targeted therapy across the continuum of CVD. The most-widely used approaches for preclinical and clinical molecular imaging include radiotracers that allow for high-sensitivity in vivo detection and quantification of molecular processes with single photon emission computed tomography and positron emission tomography. This review will describe multimodality molecular imaging instrumentation along with established and novel molecular imaging targets and probes. We will highlight how molecular imaging has provided valuable insights in determining the underlying fundamental biology of a wide variety of CVDs, including: myocardial infarction, cardiac arrhythmias, and nonischemic and ischemic heart failure with reduced and preserved ejection fraction. In addition, the potential of molecular imaging to assist in the characterization and risk stratification of systemic diseases, such as amyloidosis and sarcoidosis will be discussed. © 2019 American Physiological Society. Compr Physiol 9:477-533, 2019.

Bimodal Fucoidan-Coated Zinc Oxide/Iron Oxide-Based Nanoparticles for the Imaging of Atherothrombosis

A polyol method was used to obtain ultrasmall ZnO nanoparticles (NPs) doped with iron ions and coated with a low molecular weight fucoidan in order to perform in vivo MR and ex vivo fluorescence imaging of athrothrombosis. During the synthesis, the early elimination of water by azeotropic distillation with toluene allowed us to produce NPs which size, determined by XRD and TEM, decreased from 7 nm to 4 nm with the increase of iron/zinc ratios from 0.05 to 0.50 respectively. For the highest iron content (NP-0.50) NPs were evidenced as a mixture of nanocrystals made of wurtzite and cubic phase with a molar ratio of 2.57:1, although it was not possible to distinguish one from the other by TEM. NP-0.50 were superparamagnetic and exhibited a large emission spectrum at 470 nm when excited at 370 nm. After surface functionalization of NP-0.50 with fucoidan (fuco-0.50), the hydrodynamic size in the physiological medium was 162.0 ± 0.4 nm, with a corresponding negative zeta potential of -48.7 ± 0.4 mV, respectively. The coating was evidenced by FT-IR spectra and thermogravimetric analysis. Aqueous suspensions of fuco-0.50 revealed high transverse proton relaxivities (T₂) with an r₂ value of 173.5 mM-1 s-1 (300 K, 7.0 T) and remained stable for more than 3 months in water or in phosphate buffer saline without evolution of the hydrodynamic size and size distribution. No cytotoxic effect was observed on human endothelial cells up to 48 h with these NPs at a dose of 0.1 mg/mL. After injection into a rat model of atherothrombosis, MR imaging allowed the localization of diseased areas and the subsequent fluorescence imaging of thrombus on tissue slices.

Erythrocyte-Inspired Discoidal Polymeric Nanoconstructs Carrying Tissue Plasminogen Activator for the Enhanced Lysis of Blood Clots

Tissue plasminogen activator (tPA) is the sole approved therapeutic molecule for the treatment of acute ischemic stroke. Yet, only a small percentage of patients could benefit from this life-saving treatment because of medical contraindications and severe side effects, including brain hemorrhage, associated with delayed administration. Here, a nano therapeutic agent is realized by directly associating the clinical formulation of tPA to the porous structure of soft discoidal polymeric nanoconstructs (tPA-DPNs). The porous matrix of DPNs protects tPA from rapid degradation, allowing tPA-DPNs to preserve over 70% of the tPA original activity after 3 h of exposure to serum proteins. Under dynamic conditions, tPA-DPNs dissolve clots more efficiently than free tPA, as demonstrated in a microfluidic chip where clots are formed mimicking in vivo conditions. At 60 min post-treatment initiation, the clot area reduces by half (57 ± 8%) with tPA-DPNs, whereas a similar result (56 ± 21%) is obtained only after 90 min for free tPA. In murine mesentery venules, the intravenous administration of 2.5 mg/kg of tPA-DPNs resolves almost 90% of the blood clots, whereas a similar dose of free tPA successfully recanalizes only about 40% of the treated vessels. At about 1/10 of the clinical dose (1.0 mg/kg), tPA-DPNs still effectively dissolve 70% of the clots, whereas free tPA works efficiently only on 16% of the vessels. In vivo, discoidal tPA-DPNs outperform the lytic activity of 200 nm spherical tPA-coated nanoconstructs in terms of both percentage of successful recanalization events and clot area reduction. The conjugation of tPA with preserved lytic activity, the deformability and blood circulating time of DPNs together with the faster blood clot dissolution would make tPA-DPNs a promising nanotool for enhancing both potency and safety of thrombolytic therapies.

Exogenous imaging contrast and therapeutic agents for intravascular photoacoustic imaging and image-guided therapy

Intravascular photoacoustic (IVPA) imaging has been developed in recent years as a viable imaging modality for the assessment of atherosclerotic plaques. Exogenous imaging contrast and therapeutic agents further enhance this imaging modality and provide significant benefits. Imaging contrast agents can significantly increase photoacoustic signal, resulting in enhanced plaque detection and characterization. The ability to use these particles to molecularly target markers of disease progression makes it possible to determine patient-specific levels of risk and plan treatments accordingly. With improved diagnosis, clinicians will be able to use therapeutic agents that are synergistic with IVPA imaging to treat atherosclerotic patients. Pre-clinical and clinical studies with relevance to IVPA imaging have shown promise in the area of diagnosis and therapeutics. In this review, we present a variety of imaging contrast agents that are either designed for or are compatible with IVPA imaging, cover uses of therapeutic agents that compliment this imaging modality, and discuss future directions of research in the field.

Phosphodiesterase III inhibitor attenuates rat sinusoidal obstruction syndrome through inhibition of platelet aggregation in Disse's space

BACKGROUND AND AIM

Sinusoidal obstruction syndrome (SOS) is a serious drug-induced liver injury. However, the pathophysiology of the disease remains unclear. This study investigated the effects of cilostazol (CZ), a phosphodiesterase III inhibitor, in a monocrotaline (MCT)-induced rat model of SOS.

METHODS

Male Wistar rats were administrated MCT to induce SOS. Rats were divided into control, MCT, and MCT + CZ groups. In the MCT + CZ group, CZ was administered at 48 h, 24 h, and 30 min prior to and 8 h and 24 h after MCT administration. The MCT group was treated with water instead of CZ. At 48 h after MCT administration, blood and liver samples were collected to assess biochemistry and liver histology. Expression of rat endothelial cell antigen, CD34, CD41, P-selectin, and caspase-3 in the liver were analyzed. Plasminogen activator inhibitor-1 (PAI-1) in hepatocytes was analyzed using western blotting and polymerase chain reaction.

RESULTS

In the MCT group, macroscopic findings showed a dark-red liver surface. Histological findings showed sinusoidal dilatation, coagulative necrosis of hepatocytes, and endothelial damage of the central vein. These changes were attenuated in the MCT + CZ group. Elevated serum transaminase and decreased platelet counts were observed in the MCT + CZ group compared with those in the MCT group. Treatment with CZ reduced MCT-induced damage to the liver sinusoidal endothelial cells, inhibited extravasated platelet aggregation, and suppressed hepatocyte apoptosis around the central vein. CZ attenuated hepatic PAI-1 protein and mRNA levels.

CONCLUSIONS

Cilostazol attenuated MCT-induced SOS by preventing damage to liver sinusoidal endothelial cells and extravasated platelet aggregation. Hepatic PAI-1 levels were suppressed with CZ treatment.

Phase Transition Nanoparticles as Multimodality Contrast Agents for the Detection of Thrombi and for Targeting Thrombolysis: in Vitro and in Vivo Experiments

Thrombotic disease is extremely harmful to human health, and early detection and treatment can improve the prognosis and reduce mortality. Multimodal molecular imaging can provide abundant information about thrombi, but to date, few studies have used multimodal and multifunctional nanoparticles (NPs) for thrombus detection and for targeting thrombolysis. In this study, phase transition multimodal and multifunctional NPs (EWVDV-Fe-Ink-PFH NPs) were constructed for the first time using a three-step emulsification and carbodiimide method, and the physical and chemical properties of the NPs were investigated. The targeting abilities of the NPs and multimodal imaging, that is, photoacoustic, magnetic resonance, and ultrasound imaging, were successfully achieved in vitro and in vivo. The ability of the EWVDV peptide on the NPs to effectively target the P-selectin of thrombi was confirmed by multimodal imaging and pathology, and the penetration depths of the NPs into the thrombi were far deeper than the previously reported depths. Moreover, a perfluorohexane (PFH) phase transition induced by low-intensity focused ultrasound irradiation enabled the EWVDV-Fe-Ink-PFH NPs to cause thrombolysis in vitro. In summary, EWVDV-Fe-Ink-PFH NPs are a theranostic contrast agent that will provide a simple, effective, and noninvasive approach for the diagnosis and treatment of thrombosis.

Thrombolytic therapy based on fucoidan-functionalized polymer nanoparticles targeting P-selectin

Injection of recombinant tissue plasminogen activator (rt-PA) is the standard drug treatment for thrombolysis. However, rt-PA shows risk of hemorrhages and limited efficiency even at high doses. Polysaccharide-poly(isobutylcyanoacrylate) nanoparticles functionalized with fucoidan and loaded with rt-PA were designed to accumulate on the thrombus. Fucoidan has a nanomolar affinity for the P-selectin expressed by activated platelets in the thrombus. Solid spherical fluorescent nanoparticles with a hydrodynamic diameter of 136 ± 4 nm were synthesized by redox radical emulsion polymerization. The clinical rt-PA formulation was successfully loaded by adsorption on aminated nanoparticles and able to be released in vitro. We validated the in vitro fibrinolytic activity and binding under flow to both recombinant P-selectin and activated platelet aggregates. The thrombolysis efficiency was demonstrated in a mouse model of venous thrombosis by monitoring the platelet density with intravital microscopy. This study supports the hypothesis that fucoidan-nanoparticles improve the rt-PA efficiency. This work establishes the proof-of-concept of fucoidan-based carriers for targeted thrombolysis.

Peptide-based fibrin-targeting probes for thrombus imaging

The development of new methods to image the onset and progression of thrombosis is an unmet need. Non-invasive molecular imaging techniques targeting specific key structures involved in the formation of thrombosis have demonstrated the ability to detect thrombus in different disease state models and in patients. Due to its high concentration in the thrombus and its essential role in thrombus formation, the detection of fibrin is an attractive strategy for identification of thrombosis. Herein we provide an overview of recent and selected fibrin-targeted probes for molecular imaging of thrombosis by magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), and optical techniques. Emphasis is placed on work that our lab has explored over the last 15 years that has resulted in the progression of the fibrin-binding PET probe [64Cu]FBP8 from preclinical studies into human trials.